Are CRTs still preferred over LCDs?

JF
Posted By
John Fryatt
Jan 29, 2004
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2897
Replies
108
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Closed
That’s it really, do you think a CRT monitor is preferable, for Photoshop image editing, to an LCD monitor? And, if so, why?

I’ve always understood, from reading stuff, that a CRT gives better colour accuracy than an LCD, and has much better viewing angle. Certainly that’s true comparing my portable’s screen with the monitor on my big box. Is it still true for good quality desk-top LCDs though?

I’m just thinking about getting a new PC, and wouldn’t mind freeing up some space on the desk, which is currently dominated by two CRT monitors. Two LCDs would give me back a fair bit of space, but I wouldn’t want to lose anything, quality-wise, by going that way.

Thanks, John

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T
tacitr
Jan 29, 2004
That’s it really, do you think a CRT monitor is preferable, for Photoshop image editing, to an LCD monitor?

Yes.

Top-notch LCDs, such as Apple’s, are nearing CRT quality, but they’re still not quite there yet.

And, if so, why?

Two reasons: Color calibration and image constancy. (The latter is a big problem–even with good LCDs, the color ont he display will change as the viewing angle changes, for example as you move your head.)

Two LCDs would give me back a fair bit of space, but I
wouldn’t want to lose anything, quality-wise, by going that way.

How color-critical is your work? Top-quality LCDs are still not up to spec for demanding prepress work, but they’ve become good enough that they’re perfectly acceptable for, say, Web work.


Rude T-shirts for a rude age: http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
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W
westin*nospam
Jan 29, 2004
"John Fryatt" writes:

That’s it really, do you think a CRT monitor is preferable, for Photoshop image editing, to an LCD monitor?

No.

And, if so, why?

I’ve always understood, from reading stuff, that a CRT gives better colour accuracy than an LCD, and has much better viewing angle.

Every LCD still has some dependence on viewing angle, but it’s quite gentle in the best ones. Otherwise, the LCD wins.

Certainly that’s true comparing my portable’s screen with the monitor on my big box. Is it still true for good quality desk-top LCDs though?

Nope. Bear in mind that the laptop wants to save every milliwatt it can to extend battery life. If the LCD passes more light, less power is needed for the backlight. If that compromises color gamut or linearity, that’s a good tradeoff. But on the desktop, LCD’s can be very good.

I’m just thinking about getting a new PC, and wouldn’t mind freeing up some space on the desk, which is currently dominated by two CRT monitors. Two LCDs would give me back a fair bit of space, but I wouldn’t want to lose anything, quality-wise, by going that way.

Well, I have it from a well-known color scientist that the best of modern desktop LCD’s are better than the best CRT’s. There are several things to bear in mind, however:

1. Top-notch LCD panels and CRT’s all cost quite a bit of money; you’re in the area of $1200 for a 20-21" display.

2. Cheaper CRT’s may well be better than cheaper LCD’s; the worst LCD’s really don’t compare with pretty cheap CRT’s.

3. It’s not always clear which LCD’s fit into the "best" category. The information I have pertains to the Apple Cinema Displays; I don’t know about others.

4. Even with a good LCD, it’s not clear to me that calibration software is up to snuff. The compensation needed is different from that needed for a CRT, and it’s possible that the major software players haven’t adapted to that yet.


-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.
F
Flycaster
Jan 29, 2004
"Stephen H. Westin" <westin*> wrote in message
[snip]
Well, I have it from a well-known color scientist that the best of modern desktop LCD’s are better than the best CRT’s.
[snip]

Really? That’s the first time I’ve heard that. So he opines that, say, an Apple Cinema Display is better than a Sony Artisan or a Barco of equivalent size for color and gamma accurate pre-press work? Is this guy willing to go on the record with test results?

Don’t get me wrong, I’d love for this to be true and do away with this 80 lb lug nut on my desk! However, this just doesn’t match up with what I hear from folks who do this for a living, or from my contacts at Adobe either.

—–= Posted via Newsfeeds.Com, Uncensored Usenet News =—– http://www.newsfeeds.com – The #1 Newsgroup Service in the World! —–== Over 100,000 Newsgroups – 19 Different Servers! =—–
JF
John Fryatt
Jan 30, 2004
Thanks all, some good advice there. The upshot is that I think I’ll stick to the good old CRT monitors for the time being.
Even if a very good LCD compares favourably to a CRT, and there seems some discussion about that, I don’t want to spend that kind of cash.

Regards, John

P.S. I wonder if it’s a feature of types of newsgroup but I got better advice here than in another Photoshop group. That group is an ‘alt’ group though, so maybe slightly facetious answers are the way of things there?

"John Fryatt" wrote in message
That’s it really, do you think a CRT monitor is preferable, for Photoshop image editing, to an LCD monitor? And, if so, why?
I’ve always understood, from reading stuff, that a CRT gives better colour accuracy than an LCD, and has much better viewing angle. Certainly that’s true comparing my portable’s screen with the monitor
on
my big box. Is it still true for good quality desk-top LCDs though?
I’m just thinking about getting a new PC, and wouldn’t mind freeing up some space on the desk, which is currently dominated by two CRT monitors. Two LCDs would give me back a fair bit of space, but I wouldn’t want to lose anything, quality-wise, by going that way.
Thanks, John

G
Greg
Jan 30, 2004
"John Fryatt" wrote in message
P.S. I wonder if it’s a feature of types of newsgroup but I got better advice here than in another Photoshop group. That group is an ‘alt’ group though, so maybe slightly facetious answers are the way of things there?

I could not agree more. I don’t go to the alt…photoshop newsgroup any more at all,
for that reason. (I have no idea why it’s any different, though)

Greg.
A
Alvie
Jan 30, 2004
Between 1988 and 1998, my eyes deteriorated to the point that I need 2.5+ correction to see details I once saw with the naked eye. In 1996, a Swedish survey concluded that CRT monitors operating at Windows ‘default’ frequency of 57 Hz were able to cause epilepsy in children with no history of the disease. Between 1996 and 2003, I used about a gallon of ‘refresh’ eye drops to ease the strain of looking at a CRT screen for 10 hours a day. In June 2003 I purchased a 15" Philips 150 s4, LCD monitor to replace a Sony 21" monitor I had used for 3 years.

I have no knowledge about all the crap flycaster and his ilk go on about. I followed to instruction from my lab on how to achieve a neutral white and then followed their instructions on how to balance the colour on my new screen to produce exact (or so near as to be indistinguishable) prints based on what I see on the Philips screen.

I can absolutely guarantee that the photographs I edit on the Philips screen, will print exactly the same on my Canon S9000 and the Lambda digital photo printer at the lab. I wish I could say the Sony CRT was as easy to set up and as accurate as the LCD but it wasn’t. I spent a fortune on that Sony in the 3 years I owned it and only ever got average results.

Please yourself if you want to go with the Photoshop "Professional’s" recommendation or someone like me who makes a living from taking photographs. At the end of the day, the LCD does not cause me eye strain, is totally accurate in both colour and contrast. I get what I see from LCD and no one will ever convince me to go back to the painful days of CRT screens. All I wish now is that I had bought a 19" screen but I’ll put up with the reduced size for the comfort of using it.

The Yowie

"John Fryatt" wrote in message
That’s it really, do you think a CRT monitor is preferable, for Photoshop image editing, to an LCD monitor? And, if so, why?
I’ve always understood, from reading stuff, that a CRT gives better colour accuracy than an LCD, and has much better viewing angle. Certainly that’s true comparing my portable’s screen with the monitor on my big box. Is it still true for good quality desk-top LCDs though?
I’m just thinking about getting a new PC, and wouldn’t mind freeing up some space on the desk, which is currently dominated by two CRT monitors. Two LCDs would give me back a fair bit of space, but I wouldn’t want to lose anything, quality-wise, by going that way.
Thanks, John

G
Greg
Jan 30, 2004
I think the issue with LCDs is more to do with being able to see subtle tonal gradations,
than just colour accuracy. But we have some very nice looking LCDs indeed at the office
now, and I’m going to try one out for image editing. I’d love to be able to replace
my CRT with an LCD too, and I’m glad to see responses like yours – very promising.

Greg.

"The Yowie" wrote in message
Between 1988 and 1998, my eyes deteriorated to the point that I need 2.5+ correction to see details I once saw with the naked eye. In 1996, a
Swedish
survey concluded that CRT monitors operating at Windows ‘default’
frequency
of 57 Hz were able to cause epilepsy in children with no history of the disease. Between 1996 and 2003, I used about a gallon of ‘refresh’ eye
drops
to ease the strain of looking at a CRT screen for 10 hours a day. In June 2003 I purchased a 15" Philips 150 s4, LCD monitor to replace a Sony 21" monitor I had used for 3 years.

I have no knowledge about all the crap flycaster and his ilk go on about.
I
followed to instruction from my lab on how to achieve a neutral white and then followed their instructions on how to balance the colour on my new screen to produce exact (or so near as to be indistinguishable) prints
based
on what I see on the Philips screen.

I can absolutely guarantee that the photographs I edit on the Philips screen, will print exactly the same on my Canon S9000 and the Lambda
digital
photo printer at the lab. I wish I could say the Sony CRT was as easy to
set
up and as accurate as the LCD but it wasn’t. I spent a fortune on that
Sony
in the 3 years I owned it and only ever got average results.
Please yourself if you want to go with the Photoshop "Professional’s" recommendation or someone like me who makes a living from taking photographs. At the end of the day, the LCD does not cause me eye strain,
is
totally accurate in both colour and contrast. I get what I see from LCD
and
no one will ever convince me to go back to the painful days of CRT
screens.
All I wish now is that I had bought a 19" screen but I’ll put up with the reduced size for the comfort of using it.

The Yowie

"John Fryatt" wrote in message
That’s it really, do you think a CRT monitor is preferable, for Photoshop image editing, to an LCD monitor? And, if so, why?
I’ve always understood, from reading stuff, that a CRT gives better colour accuracy than an LCD, and has much better viewing angle. Certainly that’s true comparing my portable’s screen with the monitor on my big box. Is it still true for good quality desk-top LCDs though?
I’m just thinking about getting a new PC, and wouldn’t mind freeing up some space on the desk, which is currently dominated by two CRT monitors. Two LCDs would give me back a fair bit of space, but I wouldn’t want to lose anything, quality-wise, by going that way.
Thanks, John

B
bent*pegs69noospam*
Jan 30, 2004
"Tacit" wrote:
Top-notch LCDs, such as Apple’s, are nearing CRT quality, but they’re
still not
quite there yet.

My understanding is that Apple is full 64 bit on their graphic’s card which allows them to discern subtle shades of black. Windows-based PC’s are still running 32 bit although the 64 bit stuff is around, the software isn’t.

Maybe in a year?

B~
AQ
Aaron Queenan
Jan 30, 2004
I’m amazed at the number of people who actually leave their screen set to the default refresh rate.

Most people can see the screen flickering if the refresh rate is less than 60Hz, but I can see screen refresh rates up to nearly 80Hz. As a result, I set my refresh rate to 85Hz for the top resolution possible, and 100Hz for lower resolutions. If Windows or the video driver is too dumb to support that refresh rate, I use PowerStrip to force the graphics card to use it. Most newer monitors will happilly work at 80Hz at the recommended resolution.

Of course, running at a higher refresh rate _may_ cause the CRT or its electronics to burn out earlier (according to unsubstantiated rumours), but if it’s my eyes burning out or the CRT burning out, it’s a no-brainer. 😀

Regards,
Aaron Queenan.
J
JJS
Jan 30, 2004
I use the largest Apple Cinema Display for photographic and web work, but the pre-press person makes a final pass over everything I do for publication. She uses CRTs (a couple of them, I don’t know which.) She says I am doing a "pretty good job", which I think is very politic of her. If I did not have her help I’d might be in deep doo-doo. CRTs seem to still rule.
M
Madsen
Jan 30, 2004

B. Peg wrote:

My understanding is that Apple is full 64 bit on their graphic’s card which allows them to discern subtle shades of black. Windows-based PC’s are still running 32 bit although the 64 bit stuff is around, the software isn’t.

Apple G5 has a 64 bit CPU but that has nothing to do with the graphic card. Apple-machines use the same type of graphic cards that you use on Windows-based PC’s.

<http://www.apple.com/powermac/>
| achieving a 533MHz data rate and a maximum bandwidth of 2.1GB per | second — ideal for the ultrafast graphics cards it ships with, | like the ATI Radeon 9800 Pro or NVIDIA GeForce FX 5200 Ultra.


Regards
Madsen.
F
Flycaster
Jan 30, 2004
"The Yowie" wrote in message
[snip]
I have no knowledge about all the crap flycaster and his ilk go on about.

[snip]

Excuse me? First, I did not realize that I had "ilk", and if you are going to insult an entire group of people, at least extend them the courtesy of naming them so that they can respond if they wish. Second, I asked a sincere question followed by knowledgeable third party input, which I clearly qualified; you, on the other hand, simply expressed a personal opinion coupled with insult, and for what reason?

How informative. Yet another "class act", worthy of plonk.

—–= Posted via Newsfeeds.Com, Uncensored Usenet News =—– http://www.newsfeeds.com – The #1 Newsgroup Service in the World! —–== Over 100,000 Newsgroups – 19 Different Servers! =—–
W
westin*nospam
Jan 30, 2004
"Flycaster" writes:

"Stephen H. Westin" <westin*> wrote in message [snip]
Well, I have it from a well-known color scientist that the best of modern desktop LCD’s are better than the best CRT’s.
[snip]

Really? That’s the first time I’ve heard that. So he opines that, say, an Apple Cinema Display is better than a Sony Artisan or a Barco of equivalent size for color and gamma accurate pre-press work?

No, he, or his students, test displays.

Is this guy willing to go
on the record with test results?

Don’t get me wrong, I’d love for this to be true and do away with this 80 lb lug nut on my desk! However, this just doesn’t match up with what I hear from folks who do this for a living, or from my contacts at Adobe either.

I asked Mark Fairchild, director of the Munsell Color Lab at the Rochester Institute of Technology. Here’s the reply.

On Tuesday, October 14, 2003, at 11:49 AM, Stephen H. Westin wrote:
Mark,

How are LCD displays these days? My impression is that they have improved dramatically since your January 2000 report. Some controversy has followed the DLP/LCD test: see
< http://www.avvideo.com/2003/04_apr/features/long_live_dlp.ht m>. My impression is that this doesn’t say anything about direct-view desktop LCDs, as the light levels are so much lower. Even if there’s a direct reciprocity involved, isn’t the backlight at least 1,000 times weaker than the illumination in a video projector?

Hi Steve,

Nice to hear from you. Yes, LCD displays have improved dramatically. I use LCDs exclusively for all of our critical image and color perception research. That should say it all. The people sticking to CRTs are living in the past and holding onto myths about display technology. The most accurate color characterization we have ever had of a display in the lab was on one of the Apple Cinema Displays last year. CRTs have certainly improved as well, but I can’t see why anyone would want to use one of those blurry, low-contrast, non-uniform displays! 🙂

As with CRTs, you get what you pay for. We’ve had lot’s of good luck with the Apple Cinema Displays and the IBM T221 high-res (200dpi) LCDs. Compared to CRTs they are brighter, more spatially uniform, sharper, and higher in contrast (at the pixel level … CRTs are good at big black areas, but not at individual black pixels). Our earlier Cinema Displays did seem to age a bit more quickly than CRTs, but we haven’t noticed that yet with the more recent displays. LCDs still do have a fair bit of angular dependency, but if you sit in front of them (as we do in the visual experiments) then there isn’t a problem. LCDs get a bad reputation for color gamut because many people only see them on laptops where the gamut is smaller in order to get more light through the filters (wider spectral bandpass) to increase brightness and save battery power. The desktop units aren’t constrained that way since they can have plenty of power for the backlights. I honestly can’t think of a situation where I’d pick a CRT over and LCD (except maybe for an inexpensive television).

Now on to those projectors. Yes, the study was only on projectors and they have a ton of light on the panels. I don’t know if there is reciprocity, but I wouldn’t worry about the problem for direct-view LCDs at all. Besides that, they are completely different LCDs.
This came up in a photo newsgroup; it seems that some folks just think LCD’s are a long way from substituting for CRT’s in color-critical applications.

I guess from above you can see I disagree. I don’t think anyone is doing more color-critical work than we are! I guess the one situation, now that I think about it, to go with a CRT is if you had a few people gathered around the display making color-critical judgments simultaneously. In such a case, you might not want to have the variability with view angle of an LCD, even though it is generally pretty small these days. I think some folks will never be happy with LCDs because of their past. I just don’t understand how they can tolerate the lack of sharpness and degradation of image quality at the corners (although CRTs have improved on this front as well). Also, I wouldn’t bother with anything but a digital interface for an LCD and some people do like being able to choose different resolutions on CRTs … they are better at that since they are inherently analog.

I suspect that the discrepancy between his judgments and what you hear from folks in the field are based on history and on what I said before: high cost for a top CRT or LCD, the possibility that most LCD’s don’t fit into the "best" category, and a probable lag in software to correct LCD’s properly.


-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.
F
Flycaster
Jan 30, 2004
"Stephen H. Westin" <westin*> wrote in message
[snip]
I suspect that the discrepancy between his judgments and what you hear from folks in the field are based on history and on what I said before: high cost for a top CRT or LCD, the possibility that most LCD’s don’t fit into the "best" category, and a probable lag in software to correct LCD’s properly.

Thanks, I really appreciate the thoughtful reply. Specifically, one of the service bureaus I use for high-end Lightjet work (PC in Colorado) as well as two PS engineers have told me the problem with even the high end Apple Cinemas are 1, difficulty with profiling, and 2, innacurate contrast (as measured by continuous color ramps when viewed from [very small] differences in viewing angles.)

Nonetheless, I certainly respect your friend’s authority, and his opinion. I’ll share what he says with some of my contacts and see if they have any recent words of wisdom to offer in response. I don’t think most folks at Adobe "live in the past" – they probably play with more new display and other color-related technology than just about anyone else, your friend included, but that doesn’t necessarily mean that they are the "final authority" either. Frankly, they may well now agree – it’s been about a year since I last had the discussion with them.

Again, thanks for going the extra mile. My mind, as well as my desktop, is still open to the idea!

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GC
Graeme Cogger
Jan 30, 2004
In article <UUiSb.33987$>,
says…
<snip>
I can absolutely guarantee that the photographs I edit on the Philips screen, will print exactly the same on my Canon S9000 and the Lambda digital photo printer at the lab. I wish I could say the Sony CRT was as easy to set up and as accurate as the LCD but it wasn’t. I spent a fortune on that Sony in the 3 years I owned it and only ever got average results.
<snip>
The Yowie
Then you’ve achieved something that all the most experienced professionals in the world cannot. In fact there are
unavoidable technical reasons why your images on a monitor _cannot_ look exactly like the printouts, and especially two different technologies of printer. The best you can ever hope for is a reasonable match under controlled lighting conditions. If you want to know why, I suggest that you read "Real World Color Management" by Bruce Fraser et al.
B
Brian
Jan 30, 2004
The Yowie wrote:

I have no knowledge about all the crap flycaster and his ilk go on about.

Well, it’s not crap at all, but rather very proven in real-world experience. However, I think I have identified why you think this:

I can absolutely guarantee that the photographs I edit on the Philips screen, will print exactly the same on my Canon S9000 and the Lambda digital photo printer at the lab.

You know, it’s a lot easier to get an RGB device (in this case your LCD) to closely match another RGB device (both printers you listed). It’s much harder to get a monitor to match CMYK output, but it’s easier with CRTs than LCD.

It is for CMYK output that CRTs are still superior to current LCD technology. This will change, I am certain of it, and probably soon, but for the time being if your work involved color-critical CMYK output then you *must* use a high-end CRT – budget CRTs and LCDs across the board are not appropriate tools for the work.

Brian
B
Brian
Jan 30, 2004
Then you’ve achieved something that all the most experienced professionals in the world cannot. In fact there are
unavoidable technical reasons why your images on a monitor _cannot_ look exactly like the printouts, and especially two different technologies of printer. The best you can ever hope for is a reasonable match under controlled lighting conditions. If you want to know why, I suggest that you read "Real World Color Management" by Bruce Fraser et al.

See my other post – this Yowie guy is talking about RGB output, not CMYK.
EM
Emil Mroz
Jan 30, 2004
On Fri, 30 Jan 2004 09:53:29 -0800, "Flycaster" wrote:

"The Yowie" wrote in message
[snip]
I have no knowledge about all the crap flycaster and his ilk go on about.

[snip]

Excuse me? First, I did not realize that I had "ilk", and if you are going to insult an entire group of people, at least extend them the courtesy of naming them so that they can respond if they wish. Second, I asked a sincere question followed by knowledgeable third party input, which I clearly qualified; you, on the other hand, simply expressed a personal opinion coupled with insult, and for what reason?

How informative. Yet another "class act", worthy of plonk.

You should be honored. Most people can only dream of having a group or a sort, but you’ve got a complete ilk.

I’m impressed.


Emil
T
tacitr
Jan 30, 2004
See my other post – this Yowie guy is talking about RGB output, not CMYK.

There is no such thing as RGB output for print.

A printer, photographic image, or other device may accept RGB data, but the physical thing it produces–a sheet of paper, a photo print, whatever, *is not RGB.* And that physical output will not, and cannot, ever match an emissive RGB device like a monitor.


Rude T-shirts for a rude age: http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
GC
Graeme Cogger
Jan 30, 2004
In article ,
says…
Then you’ve achieved something that all the most experienced professionals in the world cannot. In fact there are
unavoidable technical reasons why your images on a monitor _cannot_ look exactly like the printouts, and especially two different technologies of printer. The best you can ever hope for is a reasonable match under controlled lighting conditions. If you want to know why, I suggest that you read "Real World Color Management" by Bruce Fraser et al.

See my other post – this Yowie guy is talking about RGB output, not CMYK.
I was referring to RGB output – you will still never see a perfect match.
Your point is taken about CMYK, however 🙂
J
JJS
Jan 30, 2004
"Brian" wrote in message

You know, it’s a lot easier to get an RGB device (in this case your LCD) to closely match another RGB device (both printers you listed). It’s much harder to get a monitor to match CMYK output, but it’s easier with CRTs than LCD.

RGB printer?
J
JJS
Jan 30, 2004
"Brian" wrote in message

See my other post – this Yowie guy is talking about RGB output, not CMYK.

Never heard of RGB printer output, either.
J
JJS
Jan 30, 2004
"Graeme Cogger" wrote in message

I was referring to RGB output – you will still never see a perfect match.

I think we were mainly concerned about printing, which is CMYK. Matching RGB for other monitors (Web work, etc) is unlikely and not what we were concerned about.
J
Jimmy
Jan 30, 2004
"jjs" wrote in message
"Brian" wrote in message

You know, it’s a lot easier to get an RGB device (in this case your LCD) to closely match another RGB device (both printers you listed). It’s much harder to get a monitor to match CMYK output, but it’s easier with CRTs than LCD.

RGB printer?
I think the point is that some home printers such as Epsons have to convert RGB to CMYK prior to printing.
M
Madsen
Jan 31, 2004
jjs wrote:

RGB printer?

Quoted from Real World Photoshop 7:

| Photographic printers are true RGB devices.
| They expose photosensitive paper using red, green and blue lasers | of LEDs so the CMYK color mode simply doesn’t apply.


Regards
Madsen.
M
Madsen
Jan 31, 2004
Jimmy wrote:

I think the point is that some home printers such as Epsons have to convert RGB to CMYK prior to printing.

Not only Epson printers. Both GDI (Windows) and Quickdraw (Mac), converts CMYK to RGB and sends RGB values to the printer unless you have a PostScrip-printer or RIP that understands CMYK data in-between. Neither GDI nor Quickdraw knows what CMYK is.

Quartz (OS X) should be different, but as far as I know it too has a few "gotchas" build in at the moment.


Regards
Madsen.
G
Greg
Jan 31, 2004
"Thomas Madsen" wrote in message
| Photographic printers are true RGB devices.
| They expose photosensitive paper using red, green and blue lasers | of LEDs so the CMYK color mode simply doesn’t apply.

And now go over to sci.engr.color and read the thread "Chromacities of digital photo-exposer"
to see why this statement isn’t really giving the full picture. (the red, green, and blue lasers
control the CMY levels on the paper)

Greg.
M
Madsen
Jan 31, 2004
Greg wrote:

And now go over to sci.engr.color and read the thread
"Chromacities of digital photo-exposer" to see why this statement isn’t really giving the full picture. (the red, green, and blue lasers control the CMY levels on the paper)

Okay. I’ll do that and thanks. 🙂


Regards
Madsen.
M
Madsen
Jan 31, 2004
Greg wrote:

And now go over to sci.engr.color [..]

Wow! I’ve never visited that group before. At first glance, it looks very interesting.


Regards
Madsen.
G
Greg
Jan 31, 2004
"Thomas Madsen" wrote in message
Wow! I’ve never visited that group before. At first glance, it looks very interesting.

Bugger – the secret’s out. ;^)

Greg.
M
Madsen
Jan 31, 2004
Greg wrote:

Bugger – the secret’s out. ;^)

🙂


Regards
Madsen.
U
Uni
Jan 31, 2004
Stephen H. Westin wrote:
"John Fryatt" writes:

That’s it really, do you think a CRT monitor is preferable, for Photoshop image editing, to an LCD monitor?

No.

And, if so, why?

I’ve always understood, from reading stuff, that a CRT gives better colour accuracy than an LCD, and has much better viewing angle.

Every LCD still has some dependence on viewing angle, but it’s quite gentle in the best ones. Otherwise, the LCD wins.

Indeed. Also, no constant shifting of colors and gamma with LCDs.

🙂

Uni

Certainly that’s true comparing my portable’s screen with the monitor on my big box. Is it still true for good quality desk-top LCDs though?

Nope. Bear in mind that the laptop wants to save every milliwatt it can to extend battery life. If the LCD passes more light, less power is needed for the backlight. If that compromises color gamut or linearity, that’s a good tradeoff. But on the desktop, LCD’s can be very good.

I’m just thinking about getting a new PC, and wouldn’t mind freeing up some space on the desk, which is currently dominated by two CRT monitors. Two LCDs would give me back a fair bit of space, but I wouldn’t want to lose anything, quality-wise, by going that way.

Well, I have it from a well-known color scientist that the best of modern desktop LCD’s are better than the best CRT’s. There are several things to bear in mind, however:

1. Top-notch LCD panels and CRT’s all cost quite a bit of money; you’re in the area of $1200 for a 20-21" display.

2. Cheaper CRT’s may well be better than cheaper LCD’s; the worst LCD’s really don’t compare with pretty cheap CRT’s.

3. It’s not always clear which LCD’s fit into the "best" category. The information I have pertains to the Apple Cinema Displays; I don’t know about others.

4. Even with a good LCD, it’s not clear to me that calibration software is up to snuff. The compensation needed is different from that needed for a CRT, and it’s possible that the major software players haven’t adapted to that yet.
U
Uni
Jan 31, 2004

B. Peg wrote:
"Tacit" wrote:
Top-notch LCDs, such as Apple’s, are nearing CRT quality, but they’re

still not

quite there yet.

My understanding is that Apple is full 64 bit on their graphic’s card which allows them to discern subtle shades of black.

Wow! Once again, Apple is kicking the PC graphics world in the behind.

🙂

Uni

Windows-based PC’s are still
running 32 bit although the 64 bit stuff is around, the software isn’t.
Maybe in a year?

B~

J
john
Jan 31, 2004
In article <5VBSb.8274$>, "Jimmy"
wrote:

"jjs" wrote in message

RGB printer?
I think the point is that some home printers such as Epsons have to convert RGB to CMYK prior to printing.

SOME of them? All of them convert to CMYK.
MM
max morrison
Jan 31, 2004
"Uni" wrote in message
B. Peg wrote:
"Tacit" wrote:
Top-notch LCDs, such as Apple’s, are nearing CRT quality, but they’re

still not

quite there yet.

My understanding is that Apple is full 64 bit on their graphic’s card
which
allows them to discern subtle shades of black.

Wow! Once again, Apple is kicking the PC graphics world in the behind.

And what a feeble little kick it is.

🙂

Uni

Windows-based PC’s are still
running 32 bit although the 64 bit stuff is around, the software isn’t.
Maybe in a year?

B~

MM
max morrison
Jan 31, 2004
"max morrison" wrote in message
"Uni" wrote in message
B. Peg wrote:
"Tacit" wrote:
Top-notch LCDs, such as Apple’s, are nearing CRT quality, but they’re

still not

quite there yet.

My understanding is that Apple is full 64 bit on their graphic’s card
which
allows them to discern subtle shades of black.

Wow! Once again, Apple is kicking the PC graphics world in the behind.

And what a feeble little kick it is.

Or maybe it seems feeble because the PC world has such a big posterior 🙂

🙂

Uni

Windows-based PC’s are still
running 32 bit although the 64 bit stuff is around, the software
isn’t.
Maybe in a year?

B~

XT
xalinai_Two
Jan 31, 2004
On Fri, 30 Jan 2004 06:28:17 GMT, "B. Peg"
<bent*pegs69noospam*@att.net> wrote:

"Tacit" wrote:
Top-notch LCDs, such as Apple’s, are nearing CRT quality, but they’re
still not
quite there yet.

My understanding is that Apple is full 64 bit on their graphic’s card which allows them to discern subtle shades of black. Windows-based PC’s are still running 32 bit although the 64 bit stuff is around, the software isn’t.

Both is wrong.
The average PC and the average Mac display colors in 24 bit, that is eight bit per channel.

The 32 bit color modes simply waste one byte per pixel to allow the processors (CPU and Graphics processor) to access data in pieces of four bytes a time – a lot faster than accessing the three relevant bytes separately.

There are some rare graphic adapters that have a wider bit range per color, this is usually used for calibration, very few can actually process 16bit colors (they cost more than most of us pay for the whole PC).

Some LCD manufacturers have products that can process 10 bit colors – but again this is mostly used for calibration/to compensate for the tube backlight.

Michael
A
Alvie
Jan 31, 2004
Last time one of "my ilk" posted some very simple and quite valid information about getting ‘what-you-see’ output, you began a ‘dressing down’ about why you need complex colour management in Photoshop. So my personal opinion of you, flycaster is that you are casting a bait. Your sig would be better as baitcaster. There’s no flys here.

The Yowie
——————–
"Flycaster" wrote in message
Excuse me? First, I did not realize that I had "ilk", and if you are
going
to insult an entire group of people, at least extend them the courtesy of naming them so that they can respond if they wish. Second, I asked a sincere question followed by knowledgeable third party input, which I clearly qualified; you, on the other hand, simply expressed a personal opinion coupled with insult, and for what reason?

How informative. Yet another "class act", worthy of plonk.

—–= Posted via Newsfeeds.Com, Uncensored Usenet News =—– http://www.newsfeeds.com – The #1 Newsgroup Service in the World! —–== Over 100,000 Newsgroups – 19 Different Servers! =—–
A
Alvie
Jan 31, 2004
You’re talking crap Tacit.
Red Green Blue is RGB.
Colour correction of photographic printers is via the RGB colour wheel.

The Yowie

"Tacit" wrote in message
See my other post – this Yowie guy is talking about RGB output, not CMYK.

There is no such thing as RGB output for print.

Rude T-shirts for a rude age: http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
A
Alvie
Jan 31, 2004
Cyan Magenta And Yellow are the colour wheel opposites of RGB so all that is happening is RGB.
The Yowie
———–
"Greg" wrote in message

And now go over to sci.engr.color and read the thread "Chromacities of digital photo-exposer"
to see why this statement isn’t really giving the full picture. (the red, green, and blue lasers
control the CMY levels on the paper)

Greg.

G
Greg
Jan 31, 2004
"The Yowie" wrote in message
Cyan Magenta And Yellow are the colour wheel opposites of RGB so all that
is
happening is RGB.

Well, no. All that is happening on the paper is CMY, in fact.

Greg.
G
Greg
Jan 31, 2004

I.e, these "RGB" printers are arguably no truer RGB than an inkjet printer
for which the driver accepts
RGB data and converts it to CMY(K) ) And argue we will, no doubt. 🙂

Greg.

"Greg" wrote in message
"The Yowie" wrote in message
Cyan Magenta And Yellow are the colour wheel opposites of RGB so all
that
is
happening is RGB.

Well, no. All that is happening on the paper is CMY, in fact.
Greg.

M
Madsen
Jan 31, 2004
Xalinai wrote:

Some LCD manufacturers have products that can process 10 bit colors – but again this is mostly used for calibration/to compensate for the tube backlight.

And some graphic cards can process 10 bit colors, but I’ll bet that you can’t see the difference. Maybe you can if you have one of those 10 bit LCD’s but actually my calibration package (the monitor spyder from Colorvision) seems to have a hard time calibrating and profiling my LCD when the graphic card is set to 10 bit. I have tested it several times and the calibration is more accurate when the graphic card is set to 8 bit instead of 10. I guess it’s because that the LUT of my LCD is 8 bit, but that’s just a guess.


Regards
Madsen.
U
Uni
Jan 31, 2004
The Yowie wrote:
Between 1988 and 1998, my eyes deteriorated to the point that I need 2.5+ correction to see details I once saw with the naked eye. In 1996, a Swedish survey concluded that CRT monitors operating at Windows ‘default’ frequency of 57 Hz were able to cause epilepsy in children with no history of the disease. Between 1996 and 2003, I used about a gallon of ‘refresh’ eye drops to ease the strain of looking at a CRT screen for 10 hours a day. In June 2003 I purchased a 15" Philips 150 s4, LCD monitor to replace a Sony 21" monitor I had used for 3 years.

I have no knowledge about all the crap flycaster and his ilk go on about. I followed to instruction from my lab on how to achieve a neutral white and then followed their instructions on how to balance the colour on my new screen to produce exact (or so near as to be indistinguishable) prints based on what I see on the Philips screen.

I can absolutely guarantee that the photographs I edit on the Philips screen, will print exactly the same on my Canon S9000 and the Lambda digital photo printer at the lab. I wish I could say the Sony CRT was as easy to set up and as accurate as the LCD but it wasn’t. I spent a fortune on that Sony in the 3 years I owned it and only ever got average results.
Please yourself if you want to go with the Photoshop "Professional’s" recommendation or someone like me who makes a living from taking photographs. At the end of the day, the LCD does not cause me eye strain, is totally accurate in both colour and contrast. I get what I see from LCD and no one will ever convince me to go back to the painful days of CRT screens.

Let alone the dangerous X-ray radiation of CRT monitors.

Uni

All I wish now is that I had bought a 19" screen but I’ll put up with the reduced size for the comfort of using it.

The Yowie

"John Fryatt" wrote in message

That’s it really, do you think a CRT monitor is preferable, for Photoshop image editing, to an LCD monitor? And, if so, why?
I’ve always understood, from reading stuff, that a CRT gives better colour accuracy than an LCD, and has much better viewing angle. Certainly that’s true comparing my portable’s screen with the monitor on my big box. Is it still true for good quality desk-top LCDs though?
I’m just thinking about getting a new PC, and wouldn’t mind freeing up some space on the desk, which is currently dominated by two CRT monitors. Two LCDs would give me back a fair bit of space, but I wouldn’t want to lose anything, quality-wise, by going that way.
Thanks, John

F
Flycaster
Jan 31, 2004
"The Yowie" wrote in message
Last time one of "my ilk" posted some very simple and quite valid information about getting ‘what-you-see’ output, you began a ‘dressing
down’
about why you need complex colour management in Photoshop. So my personal opinion of you, flycaster is that you are casting a bait. Your sig would
be
better as baitcaster. There’s no flys here.

The Yowie

Ahh, technoaussie, I should have known. I never gave anyone a "dressing down", rather my exact quote was,"And I think all that is very commendable, but for goodness sake stop telling people to "turn off color management."" Moreover, I stand by that statement today, and if that actually "hurts" your feelings, I suggest you consider therapy coupled with drug and alcohol treatment…you need it.

You now join your other "ilk" in the kill file, while I get back to something more productive. Have the last word if you must, but it certainly won’t be for my benefit, much less my attention.

—–= Posted via Newsfeeds.Com, Uncensored Usenet News =—– http://www.newsfeeds.com – The #1 Newsgroup Service in the World! —–== Over 100,000 Newsgroups – 19 Different Servers! =—–
MR
Mike Russell
Jan 31, 2004
Thomas Madsen wrote:
Xalinai wrote:

Some LCD manufacturers have products that can process 10 bit colors – but again this is mostly used for calibration/to compensate for the tube backlight.

And some graphic cards can process 10 bit colors, but I’ll bet that you can’t see the difference. Maybe you can if you have one of those 10 bit LCD’s but actually my calibration package (the monitor spyder from Colorvision) seems to have a hard time calibrating and profiling my LCD when the graphic card is set to 10 bit. I have tested it several times and the calibration is more accurate when the graphic card is set to 8 bit instead of 10. I guess it’s because that the LUT of my LCD is 8 bit, but that’s just a guess.

8 bits is enough for gamma 1.8 and 2.2/2.5, which are normal for Mac and PC, respectively.

If your monitor is set to linear gamma – admittedly rare, but standard in some segments of the film industry – you can see 10 bits. Linear to film will show 12 bits per channel.


Mike Russell
www.curvemeister.com
www.geigy.2y.net
M
Madsen
Jan 31, 2004
Mike Russell wrote:

If your monitor is set to linear gamma – admittedly rare, but standard in some segments of the film industry – you can see 10 bits. Linear to film will show 12 bits per channel.

Yes, but according to Matrox, you should see the difference in programs like Photoshop for instance and if that’s true, then there’s something wrong with my eyes because I can’t.
They forget to mention that most monitors can’t show you more than 8 bit per channel (and often less).


Regards
Madsen.
MR
Mike Russell
Jan 31, 2004
Thomas Madsen wrote:
Mike Russell wrote:

If your monitor is set to linear gamma – admittedly rare, but standard in some segments of the film industry – you can see 10 bits. Linear to film will show 12 bits per channel.

Yes, but according to Matrox, you should see the difference in programs like Photoshop for instance and if that’s true, then there’s something wrong with my eyes because I can’t.
They forget to mention that most monitors can’t show you more than 8 bit per channel (and often less).

You’re right if you’re implying that it’s mostly marketing hype on Matrox’s part, but I have developed apps where the 10 bits really mattered. There are applications where >8 bits makes a difference, and arguably some of those are on a normal CRT.

Even with gamma 2.2 you can see banding in the shadows on a high-quality monochrome display, such as those used in medical applications for viewing CT data. These are computed images which have 10 or even 12 bits of linear significant digits.

For a color monitor you can still see banding in the shadows if you crank up the output of the card to get closer to a linear gamma on the CRT. Of course, everything outside of Photoshop will look like it’s been soaked in bleach, but there you have it.


Mike Russell
www.curvemeister.com
www.geigy.2y.net
G
Greg
Feb 1, 2004
"Mike Russell" wrote in message
Even with gamma 2.2 you can see banding in the shadows on a high-quality monochrome display, such as those used in medical applications for viewing CT data. These are computed images which have 10 or even 12 bits of
linear
significant digits.

It takes *14* bits at gamma 1 to provide the same shadow detail as 8-bit gamma 2.2.

Greg.
M
Madsen
Feb 1, 2004
Mike Russell wrote:

For a color monitor you can still see banding in the shadows if you crank up the output of the card to get closer to a linear gamma on the CRT.

I’m not sure what you mean when you say linear gamma. Does it mean a gamma of 1.0?


Regards
Madsen.
JW
JP White
Feb 1, 2004
The Yowie wrote:
You’re talking crap Tacit.
Red Green Blue is RGB.
Colour correction of photographic printers is via the RGB colour wheel.
I think you miss Tacit’s point.

While you are correct to say that consumer level photo printers are aligned with the rgb color space (because that whats most people/software throws at them), the final output on paper *has* to be CMYK. You have to subtract color from the white paper. The CRT adds color to the black backdrop and is a true rgb device.

Input to consumer level photo printer = RGB
output from printer = CMYK.

Sending CMYK data to the print driver is sub optimal since it will convert it to rgb anyhow (since it has an rgb input) then output as CMYK onto the paper itself.

If you look at your color ink cartridges none of them are labeled red, green or blue.

Having said all that, it does make sense to edit in rgb since that’s what the printer is expecting and is designed to deal with and the average CRT can display that natively.

JP
MR
Mike Russell
Feb 1, 2004
JP White wrote:
The Yowie wrote:
You’re talking crap Tacit.
Red Green Blue is RGB.
Colour correction of photographic printers is via the RGB colour wheel.
I think you miss Tacit’s point.

While you are correct to say that consumer level photo printers are aligned with the rgb color space (because that whats most people/software throws at them), the final output on paper *has* to be CMYK. You have to subtract color from the white paper. The CRT adds color to the black backdrop and is a true rgb device.

Input to consumer level photo printer = RGB
output from printer = CMYK.

Sending CMYK data to the print driver is sub optimal since it will convert it to rgb anyhow (since it has an rgb input) then output as CMYK onto the paper itself.

If you look at your color ink cartridges none of them are labeled red, green or blue.

Having said all that, it does make sense to edit in rgb since that’s what the printer is expecting and is designed to deal with and the average CRT can display that natively.

Edit space and display space need not be the same. There are advantages to editing in Lab and CMYK, or even HSB, and no reason to stay in RGB simply because the printer driver happens to speak RGB.


Mike Russell
www.curvemeister.com
www.geigy.2y.net
G
Greg
Feb 2, 2004
I’ve just tried a Compaq TFT8020 at the office. I could *easily* use this thing for my digital photography.
(speaking as a rank amateur, however)

Also, despite the lack of blue gamut compared to a CRT, this doesn’t matter to me, for printing –
my printer can’t display those blues anyway. In fact, the position of the blue chromacity actually
should give the monitor (in theory, anyway) a very slight increase in cyan gamut, which is an *advantage* over a CRT
for print work.

Greg.
AQ
Aaron Queenan
Feb 2, 2004
"Greg" wrote in message
I’ve just tried a Compaq TFT8020 at the office. I could *easily* use this
thing for my digital photography.
(speaking as a rank amateur, however)

Also, despite the lack of blue gamut compared to a CRT, this doesn’t
matter to me, for printing –
my printer can’t display those blues anyway. In fact, the position of the
blue chromacity actually
should give the monitor (in theory, anyway) a very slight increase in cyan
gamut, which is an
*advantage* over a CRT for print work.

I’ve also noticed that deep reds appear on a CRT as a bright red, whereas on ad LCD they look closer to the scanned image (and therefore probably closer to the print colour), and as another poster has mentioned, LCDs cope much better with smaller areas of black than CRTs can. I would be interested in seeing a proper comparison between the two.

Regards,
Aaron.
W
westin*nospam
Feb 2, 2004
Uni writes:

B. Peg wrote:
"Tacit" wrote:
Top-notch LCDs, such as Apple’s, are nearing CRT quality, but they’re
still not

quite there yet.
My understanding is that Apple is full 64 bit on their graphic’s card which
allows them to discern subtle shades of black.

Wow! Once again, Apple is kicking the PC graphics world in the behind.
🙂

Nah. Current Apple products use graphics cards that are available for PC’s as well. I think nVidia is the current favorite.

<snip>


-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.
G
Greg
Feb 2, 2004
"Aaron Queenan" wrote in message
I’ve also noticed that deep reds appear on a CRT as a bright red, whereas
on
ad LCD they look closer to the scanned image (and therefore probably
closer
to the print colour), and as another poster has mentioned, LCDs cope much better with smaller areas of black than CRTs can. I would be interested
in
seeing a proper comparison between the two.

The red and green "phosphors" look *very* close to a standard monitor in chromacity values. I don’t think
the LCD I tested will show much difference for reds, in comparison with a CRT, assuming both are properly
calibrated and profiled, and assuming both are calibrated to the same whitepoint, and the scan is viewed
in an identical fashion in a colour managed application.

Greg.
W
westin*nospam
Feb 2, 2004
Thomas Madsen writes:

Mike Russell wrote:

For a color monitor you can still see banding in the shadows if you crank up the output of the card to get closer to a linear gamma on the CRT.

I’m not sure what you mean when you say linear gamma. Does it mean a gamma of 1.0?

Yup. Put an image in the frame buffer with no gamma correction, and use the LUT’s to correct it. I’d like 12 bits in the frame buffer for that situation.


-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.
B
Brian
Feb 2, 2004
Tacit wrote:
There is no such thing as RGB output for print.

Tell that to a photo printer such as Photoaccess.com, which use true RGB output to produce photographic prints. No CMYK whatsoever… and most inkjet printers (including the one Yowie referenced) take RGB data, even if the file being printed is CMYK, and the chances of getting a good match from screen to print is much higher when the source data is RGB to begin with (which I believe he/she is using).

Regardless, we are talking about the same thing in essence, and Yowie is talking out of his ass.
B
Brian
Feb 2, 2004
SOME of them? All of them convert to CMYK.

But some printers can keep CMYK data in CMYK mode, whereas the average inkjet will convert CMYK to RGB, and then back to CMYK for output.
B
Brian
Feb 2, 2004
| Photographic printers are true RGB devices.
| They expose photosensitive paper using red, green and blue lasers | of LEDs so the CMYK color mode simply doesn’t apply.

And now go over to sci.engr.color and read the thread "Chromacities of digital photo-exposer"
to see why this statement isn’t really giving the full picture. (the red, green, and blue lasers
control the CMY levels on the paper)

But there is a direct correlation between RGB and CMY (i.e. for any given RGB color there is a specific CMY equivalent, unlike CMYK where you can achieve the same color in print using many different variations of the CMYK values), so there is no "conversion" required in this type of printing.
NS
Nicholas Sherlock
Feb 2, 2004
Brian wrote:
Tacit wrote:
There is no such thing as RGB output for print.

Tell that to a photo printer such as Photoaccess.com, which use true RGB output to produce photographic prints. No CMYK whatsoever

So the ink droplets used are red, green, and blue? Or are they in fact still C,M,Y,K, so a conversion must take place from RGB to CMYK by the printer to know how much ink of each type is needed?

Cheers,
Nicholas Sherlock
SM
Steve McGillivray
Feb 2, 2004
On 2/2/04 11:48 AM, in article bvm601$ojv$, "Nicholas Sherlock" wrote:

Brian wrote:
Tacit wrote:
There is no such thing as RGB output for print.

Tell that to a photo printer such as Photoaccess.com, which use true RGB output to produce photographic prints. No CMYK whatsoever

So the ink droplets used are red, green, and blue? Or are they in fact still C,M,Y,K, so a conversion must take place from RGB to CMYK by the printer to know how much ink of each type is needed?

Cheers,
Nicholas Sherlock
Yeah, how would you get yellow from RGB inks?
J
JJS
Feb 2, 2004
Brian wrote:
Tacit wrote:
There is no such thing as RGB output for print.

Tell that to a photo printer such as Photoaccess.com, which use true RGB output to produce photographic prints. No CMYK whatsoever

If they use RGB in that manner, then they don’t use ink! They use wet photographic (conventional) printing. Sheesh.
J
JJS
Feb 2, 2004
"jjs" wrote in message
Brian wrote:
Tacit wrote:
There is no such thing as RGB output for print.

Tell that to a photo printer such as Photoaccess.com, which use true RGB output to produce photographic prints. No CMYK whatsoever

If they use RGB in that manner, then they don’t use ink! They use wet photographic (conventional) printing. Sheesh.

(Which uses CMY filtration!)
F
Flycaster
Feb 2, 2004
"jjs" wrote in message
"jjs" wrote in message
Brian wrote:
Tacit wrote:
There is no such thing as RGB output for print.

Tell that to a photo printer such as Photoaccess.com, which use true RGB output to produce photographic prints. No CMYK whatsoever

If they use RGB in that manner, then they don’t use ink! They use wet photographic (conventional) printing. Sheesh.

(Which uses CMY filtration!)

I think he’s referring to devices that use RGB lasers to expose tradtional wet photographic papers ~ no "CMY filtration" involved. The rest of this discussion results from the failure (on the part of some) to understand the difference between a "driver" and an ink-based "printer."

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B
Brian
Feb 2, 2004
So the ink droplets used are red, green, and blue? Or are they in fact still C,M,Y,K, so a conversion must take place from RGB to CMYK by the printer to know how much ink of each type is needed?

There is no ink, it is a photomechanical process.
http://www.photoaccess.com/user/howPrints.jsp ;jsessionid=FEB4863B9B97551D100D954524D2A188?cb=PA&svr=w eb6
B
Brian
Feb 2, 2004
jjs wrote:
If they use RGB in that manner, then they don’t use ink! They use wet photographic (conventional) printing. Sheesh.

What’s the "sheesh" for? We’re all beating around the same damn bush, which is that Yowie is NOT referring to calibrating his LCD monitor for CMYK output, which is what the rest of us are talking about when we say that for color-critical work CRTs are still a requirement.
J
JJS
Feb 2, 2004
"Brian" wrote in message
So the ink droplets used are red, green, and blue? Or are they in fact
still
C,M,Y,K, so a conversion must take place from RGB to CMYK by the printer
to
know how much ink of each type is needed?

There is no ink, it is a photomechanical process.
http://www.photoaccess.com/user/howPrints.jsp ;jsessionid=FEB4863B9B97551D100D954524D2A188?cb=PA&svr=w eb6

I was wondering when someone would notice that. And, of course, conventional color printing use CMY. (K is the absense of exposure.)
J
JJS
Feb 2, 2004
"Brian" wrote in message
jjs wrote:
If they use RGB in that manner, then they don’t use ink! They use wet photographic (conventional) printing. Sheesh.

What’s the "sheesh" for? […]

It’s a speech impediment. Yeah, that’s the ticket. Speech problem. That’s my story and I’m sticking to it.
G
Greg
Feb 3, 2004
When I wrote this (below), I was comparing the supplied monitor profile for the LCD (the Compaq TFT8020),
to a generic monitor profile I had on my system. However, upon actually measuring the red chromacities of
my CRT that I’m using at the moment, it’s not as deep as the value in the generic monitor profile. It’s actually
very close to the Trinitron red chromacity, and as it turns out, this CRT is a Trinitron. (an old DEC VRC21).
The LCD’s red measures *very* close to the chromacity in it’s associated profile, and seems to be quite
close to the EBU red chromacity (actually a bit better than even EBU).

So Aaron, I think you’re absolutely right, even for my LCD. It really can produce deeper reds than a typical CRT.

I’m using the Eye One Display monitor puck to take the measurements. Seems to be doing a stirling job.

Greg.

"Greg" wrote in message
"Aaron Queenan" wrote in
message
I’ve also noticed that deep reds appear on a CRT as a bright red,
whereas
on
ad LCD they look closer to the scanned image (and therefore probably
closer
to the print colour), and as another poster has mentioned, LCDs cope
much
better with smaller areas of black than CRTs can. I would be interested
in
seeing a proper comparison between the two.

The red and green "phosphors" look *very* close to a standard monitor in chromacity values. I don’t think
the LCD I tested will show much difference for reds, in comparison with a CRT, assuming both are properly
calibrated and profiled, and assuming both are calibrated to the same whitepoint, and the scan is viewed
in an identical fashion in a colour managed application.
Greg.

G
Greg
Feb 3, 2004
(also, you don’t need me to confirm what your eyes tell you – sorry if I’m coming across as being
a bit autocratic)

"Greg" wrote in message
When I wrote this (below), I was comparing the supplied monitor profile
for
the LCD (the Compaq TFT8020),
to a generic monitor profile I had on my system. However, upon actually measuring the red chromacities of
my CRT that I’m using at the moment, it’s not as deep as the value in the generic monitor profile. It’s actually
very close to the Trinitron red chromacity, and as it turns out, this CRT
is
a Trinitron. (an old DEC VRC21).
The LCD’s red measures *very* close to the chromacity in it’s associated profile, and seems to be quite
close to the EBU red chromacity (actually a bit better than even EBU).
So Aaron, I think you’re absolutely right, even for my LCD. It really can produce deeper reds than a typical CRT.

I’m using the Eye One Display monitor puck to take the measurements. Seems to be doing a stirling job.

Greg.

"Greg" wrote in message
"Aaron Queenan" wrote in
message
I’ve also noticed that deep reds appear on a CRT as a bright red,
whereas
on
ad LCD they look closer to the scanned image (and therefore probably
closer
to the print colour), and as another poster has mentioned, LCDs cope
much
better with smaller areas of black than CRTs can. I would be
interested
in
seeing a proper comparison between the two.

The red and green "phosphors" look *very* close to a standard monitor in chromacity values. I don’t think
the LCD I tested will show much difference for reds, in comparison with
a
CRT, assuming both are properly
calibrated and profiled, and assuming both are calibrated to the same whitepoint, and the scan is viewed
in an identical fashion in a colour managed application.
Greg.

G
Greg
Feb 3, 2004
By the way, is simply measuring the chromacities of a display too simplistic, to determine it’s gamut?
Are there other factors which are as important, or even more important, than just the chromacities?

For example, does a typical LCD retain the purity of it’s "phosphors" (filters) as intensity is varied?

Greg.
U
Uni
Feb 3, 2004
Greg wrote:
When I wrote this (below), I was comparing the supplied monitor profile for the LCD (the Compaq TFT8020),
to a generic monitor profile I had on my system. However, upon actually measuring the red chromacities of
my CRT that I’m using at the moment, it’s not as deep as the value in the generic monitor profile. It’s actually
very close to the Trinitron red chromacity, and as it turns out, this CRT is a Trinitron. (an old DEC VRC21).
The LCD’s red measures *very* close to the chromacity in it’s associated profile, and seems to be quite
close to the EBU red chromacity (actually a bit better than even EBU).
So Aaron, I think you’re absolutely right, even for my LCD. It really can produce deeper reds than a typical CRT.

People are just afraid to change. That’s all.

Uni

I’m using the Eye One Display monitor puck to take the measurements. Seems to be doing a stirling job.

Greg.

"Greg" wrote in message

"Aaron Queenan" wrote in

message


I’ve also noticed that deep reds appear on a CRT as a bright red,
whereas

on

ad LCD they look closer to the scanned image (and therefore probably

closer

to the print colour), and as another poster has mentioned, LCDs cope
much

better with smaller areas of black than CRTs can. I would be interested

in

seeing a proper comparison between the two.

The red and green "phosphors" look *very* close to a standard monitor in chromacity values. I don’t think
the LCD I tested will show much difference for reds, in comparison with a CRT, assuming both are properly
calibrated and profiled, and assuming both are calibrated to the same whitepoint, and the scan is viewed
in an identical fashion in a colour managed application.
Greg.

F
Flycaster
Feb 3, 2004
"Greg" wrote in message
[snip]
I’m using the Eye One Display monitor puck to take the measurements. Seems to be doing a stirling job.

Excellent tools, aren’t they? Are you just using their puck, or do you have one of their bundled packages? (I can’t recall…)

—–= Posted via Newsfeeds.Com, Uncensored Usenet News =—– http://www.newsfeeds.com – The #1 Newsgroup Service in the World! —–== Over 100,000 Newsgroups – 19 Different Servers! =—–
G
Greg
Feb 3, 2004
"Flycaster" wrote in message
Excellent tools, aren’t they? Are you just using their puck, or do you
have
one of their bundled packages? (I can’t recall…)

I got the Eye One Display bundle. (i.e, the puck, and the Eye One Match and ancilliary software).
However, to make spot measurements, I am using the free Measure Tool which is part of the Profile
Maker Pro 4.1.5 download.

Greg.
G
Greg
Feb 3, 2004
"Uni" wrote in message
People are just afraid to change. That’s all.

Yes, I think so, to an extent.We all have different needs. I can believe that the best CRTs
may well still beat the best LCDs, but that’s irrelevant to me. The only question which is
relevant to me is "can I use an LCD for my amateur photography?", and the answer seems to
be a resounding "yes". The LCD I tested is some three years old, too, so current technology
is likely to be even better.

Greg.
AQ
Aaron Queenan
Feb 3, 2004
"Greg" wrote in message
(also, you don’t need me to confirm what your eyes tell you – sorry if I’m coming across as being
a bit autocratic)

No offense taken. 🙂

It reminds me of the refresh rate debate when I start a new job. I can’t stand a refresh rate less than 80Hz, and 75Hz is visibly shaking for me, but a lot of people don’t even perceive the image to be vibrating with a 60Hz refresh rate. It’s kind of hard to convince someone based on something you can clearly see but that they can’t. 🙁

Come to think of it, since our eyes are all different, and the receptivity curves for short, medium and long wavelengths vary, it is entirely possible that I would see a colour as being a deeper red, and you would see the same thing as a more orangy red. 😀

Aaron.
G
Greg
Feb 3, 2004
"Aaron Queenan" wrote in message
Come to think of it, since our eyes are all different, and the receptivity curves for short, medium and long wavelengths vary, it is entirely
possible
that I would see a colour as being a deeper red, and you would see the
same
thing as a more orangy red. 😀

One reason I went back and investigated this is that I took at look at the LCD displaying a deep red,
and thought to myself that it really did look a bit better than my CRT, and darn it, this Aaron chap
may actually be right. 🙂

Greg.
G
Greg
Feb 3, 2004
Also, re: the EBU phoshors, obviously some CRTs do have EBU phosphors. So they’d probably
compare favourably for reds with these LCDs. I once asked Barco whether they had any
monitor with a substantially wider gamut than normal, and they pointed me to some monitors
which use EBU phosphors. I don’t think EBU is very much wider than normal though – nothing
like the Adobe RGB monitor.

Greg.

"Greg" wrote in message
"Aaron Queenan" wrote in
message
Come to think of it, since our eyes are all different, and the
receptivity
curves for short, medium and long wavelengths vary, it is entirely
possible
that I would see a colour as being a deeper red, and you would see the
same
thing as a more orangy red. 😀

One reason I went back and investigated this is that I took at look at the LCD displaying a deep red,
and thought to myself that it really did look a bit better than my CRT,
and
darn it, this Aaron chap
may actually be right. 🙂

Greg.

W
westin*nospam
Feb 3, 2004
"Greg" writes:

By the way, is simply measuring the chromacities of a display too simplistic, to determine it’s gamut?
Are there other factors which are as important, or even more important, than just the chromacities?

For example, does a typical LCD retain the purity of it’s "phosphors" (filters) as intensity is varied?

Take a look at
< http://www.cis.rit.edu/research/mcsl/research/PDFs/GibsonFai rchild.pdf> for a deep look at LCD characterization. The report is several years old, so don’t use it as a guide to the performance of current LCD’s; some of the newer ones are considerably better. But it gives a glimpse of the issues involved and why a calibration scheme developed for CRT’s might not be optimal for an LCD. Oh, and there’s an even older report that’s relevant in the same sort of way:
<http://www.cis.rit.edu/mcsl/research/PDFs/LCD.pdf>


-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.
AQ
Aaron Queenan
Feb 3, 2004
"Greg" wrote in message
Also, re: the EBU phoshors, obviously some CRTs do have EBU phosphors. So
they’d probably
compare favourably for reds with these LCDs. I once asked Barco whether
they had any
monitor with a substantially wider gamut than normal, and they pointed me
to some monitors
which use EBU phosphors. I don’t think EBU is very much wider than normal
though
– nothing like the Adobe RGB monitor.

Do any Adobe RGB monitors exist yet outside of the lab? The only one I can find is the Mitsubishi RDF225WG, and all the info is in Japanese, but it’s supposed to cover 98% of the Adobe RGB gamut. Do you know of any others, or have links to any?

Thanks,
Aaron.
M
Madsen
Feb 3, 2004
Greg wrote:

So Aaron, I think you’re absolutely right, even for my LCD. It really can produce deeper reds than a typical CRT.

The same thing is true for my LCD. It goes deeper in to the reds than my CRT. It’s easy to see if I compare the two profiles in a 3D-viewer. Actually, the LCD goes a little further into the cyan- like blues too. Not much though, but a little.

< http://home18.inet.tele.dk/madsen/monitor/vp201s_vs_fw900_re d.jpg> < http://home18.inet.tele.dk/madsen/monitor/vp201s_vs_fw900_bl ue.jpg>


Regards
Madsen.
G
Greg
Feb 3, 2004
"Aaron Queenan" wrote in message
Do any Adobe RGB monitors exist yet outside of the lab? The only one I
can
find is the Mitsubishi RDF225WG, and all the info is in Japanese, but it’s supposed to cover 98% of the Adobe RGB gamut. Do you know of any others,
or
have links to any?

That’s the only one I know of, and I don’t know the release status of the product.

Greg.
AQ
Aaron Queenan
Feb 3, 2004
"Thomas Madsen" wrote in message
The same thing is true for my LCD. It goes deeper in to the reds than my CRT. It’s easy to see if I compare the two profiles in a 3D-viewer. Actually, the LCD goes a little further into the cyan- like blues too. Not much though, but a little.

< http://home18.inet.tele.dk/madsen/monitor/vp201s_vs_fw900_re d.jpg> < http://home18.inet.tele.dk/madsen/monitor/vp201s_vs_fw900_bl ue.jpg>

Regards
Madsen.

Out of interest, what program are you using for displaying the profiles? Is it freeware or part of a colour profiling package?

Thanks,
Aaron.
G
Greg
Feb 3, 2004
Thomas,
I don’t think those results are correct. I suspect you have used a non-D50 based monitor profile, and the Eye One Match
software? Repeat the experiment, comparing two D50 based profiles. The Eye One Match software creates profiles
for which the chromacities do not match the hardware, if the hardware whitepoint is different to D50. (this is almost
certainly a valid thing to do, but it screws up gamut displays)

Greg.
"Thomas Madsen" wrote in message
Greg wrote:

So Aaron, I think you’re absolutely right, even for my LCD. It really can produce deeper reds than a typical CRT.

The same thing is true for my LCD. It goes deeper in to the reds than my CRT. It’s easy to see if I compare the two profiles in a 3D-viewer. Actually, the LCD goes a little further into the cyan- like blues too. Not much though, but a little.

< http://home18.inet.tele.dk/madsen/monitor/vp201s_vs_fw900_re d.jpg> < http://home18.inet.tele.dk/madsen/monitor/vp201s_vs_fw900_bl ue.jpg>

Regards
Madsen.
G
Greg
Feb 3, 2004

I.e, if you take spot measurements of your phosphors, I don’t think they’ll
match the chromacities
in your gamut plots. If you profile for D50, they will match the hardware.

Greg.
"Greg" wrote in message
Thomas,
I don’t think those results are correct. I suspect you have used a non-D50 based monitor profile, and the Eye One Match
software? Repeat the experiment, comparing two D50 based profiles. The Eye One Match software creates profiles
for which the chromacities do not match the hardware, if the hardware whitepoint is different to D50. (this is almost
certainly a valid thing to do, but it screws up gamut displays)
Greg.
"Thomas Madsen" wrote in message
Greg wrote:

So Aaron, I think you’re absolutely right, even for my LCD. It really can produce deeper reds than a typical CRT.

The same thing is true for my LCD. It goes deeper in to the reds than my CRT. It’s easy to see if I compare the two profiles in a 3D-viewer. Actually, the LCD goes a little further into the cyan- like blues too. Not much though, but a little.

< http://home18.inet.tele.dk/madsen/monitor/vp201s_vs_fw900_re d.jpg> < http://home18.inet.tele.dk/madsen/monitor/vp201s_vs_fw900_bl ue.jpg>

Regards
Madsen.

M
Madsen
Feb 3, 2004
Greg wrote:

I don’t think those results are correct. I suspect you have used a non-D50 based monitor profile, and the Eye One Match
software?

No. I have used OptiCAL and the spyder to calibrate and profile my two monitors. Then I have compared the two profiles. Is that the wrong way to go?

Repeat the experiment, comparing two D50 based profiles. The Eye One Match software creates profiles
for which the chromacities do not match the hardware, if the hardware whitepoint is different to D50. (this is almost certainly a valid thing to do, but it screws up gamut displays)

You mean that I should calibrate the two monitors to D50 and then profile them instead? Why should I pick D50 instead of say D65?


Regards
Madsen.
M
Madsen
Feb 3, 2004
Aaron Queenan wrote:

Out of interest, what program are you using for displaying the profiles?

iccProfile Viewer.
< https://www.chromaticity.com/Store/ShowProduct.asp?ProductID =1063>


Regards
Madsen.
G
Greg
Feb 3, 2004
"Thomas Madsen" wrote in message
No. I have used OptiCAL and the spyder to calibrate and profile my two monitors. Then I have compared the two profiles. Is that the wrong way to go?

Ah, ok – sorry.

You mean that I should calibrate the two monitors to D50 and then profile them instead? Why should I pick D50 instead of say D65?

Before you go to that trouble, take spot readings, and work out the x,y coordinates, and see if they match your gamut plot. (or see if they match the coordinates in your monitor profiles). I have a strong hunch that they won’t. If they don’t, then reprofile both to D50, because then the monitor profiles will probably contain the real chromacities, and the gamut plots will more closely reflect reality. It’s due to a quirk in the way some of today’s
monitor profiles are created.

Greg.
M
Madsen
Feb 3, 2004
Greg wrote:

It’s due to a quirk in the way some of today’s monitor profiles are created.

Ok. I’m not sure if it has anything to do with the quirk you mention, but one of the fixes in OptiCAL 3.7.6, which I use, is this:

| Colorant Tags in ICC profiles are now correctly adapted to D50


Regards
Madsen.
G
Greg
Feb 4, 2004
"Thomas Madsen" wrote in message

| Colorant Tags in ICC profiles are now correctly adapted to D50

This makes me think that your profiles will in fact have the "faked" chromacities, when
the actual monitor whitepoint is not calibrated to D50.

Greg.
M
Madsen
Feb 4, 2004
Greg wrote:

This makes me think that your profiles will in fact have the "faked" chromacities, when the actual monitor whitepoint is not calibrated to D50.

Hmm, god damn! Well, back to the old drawing board. 😉


Regards
Madsen.
G
Greg
Feb 4, 2004
I’m not totally sure yet – I only had a quick look at your chromacity diagram.

I’m not saying there’s anything "wrong" with the "faked" chromacities, even if
the profiles are like that. There is a "chrm" tag available to put the hardware
chromacities – just maybe your profiles have that tag? If so, you ought to be able
to just read the chromacities from that tag, I think.

Just in case you don’t know how to work out the x,y chromacities, and your measurement software can’t give you the values directly, all you need to do is take XYZ spot readings, and then compute x = X/(X+Y+Z), y=Y/(X+Y+Z). But you probably already know this.

Greg.
"Thomas Madsen" wrote in message
Greg wrote:

This makes me think that your profiles will in fact have the "faked" chromacities, when the actual monitor whitepoint is not calibrated to D50.

Hmm, god damn! Well, back to the old drawing board. 😉


Regards
Madsen.
M
Madsen
Feb 4, 2004
Greg wrote:

There is a "chrm" tag available to put the hardware chromacities – just maybe your profiles have that tag? If so, you ought to be able to just read the chromacities from that tag, I think.

No, my profiles doesn’t have that tag, as far as I can see. I only have the following tags in the profiles made with OptiCAL: <http://home18.inet.tele.dk/madsen/monitor/tags.gif>.

Just in case you don’t know how to work out the x,y chromacities, and your measurement software can’t give you the values directly, all you need to do is take XYZ spot readings, and then compute x = X/(X+Y+Z), y=Y/(X+Y+Z). But you probably already know this.

No I didn’t knew how to calculate it, so thanks. 🙂

Actually I’m a little confused here Greg.
You mean that I should calibrate the monitor to D50 and then produce a new profile, right?

I can choose D50 as the white point in OptiCAL and on the following screen shot you can see which measurements OptiCAL can give me: <http://home18.inet.tele.dk/madsen/monitor/optical.gif>


Regards
Madsen.
G
Greg
Feb 4, 2004
Thomas,
Good – you can get xyY readings, so just display a patch of full scale red, green, and blue, and take the respective
spot measurements in xyY. Don’t bother about re-calibrating or re-profiling yet.

I’ve had a closer look at your chromacity diagram, and the LCD chromacities look lik they may be real. The Trinitron
chromacities don’t really look correct to me, particularly the red and green.

Greg.

"Thomas Madsen" wrote in message
Greg wrote:

There is a "chrm" tag available to put the hardware chromacities – just maybe your profiles have that tag? If so, you ought to be able to just read the chromacities from that tag, I think.

No, my profiles doesn’t have that tag, as far as I can see. I only have the following tags in the profiles made with OptiCAL: <http://home18.inet.tele.dk/madsen/monitor/tags.gif>.
Just in case you don’t know how to work out the x,y chromacities, and your measurement software can’t give you the values directly, all you need to do is take XYZ spot readings, and then compute x = X/(X+Y+Z), y=Y/(X+Y+Z). But you probably already know this.

No I didn’t knew how to calculate it, so thanks. 🙂

Actually I’m a little confused here Greg.
You mean that I should calibrate the monitor to D50 and then produce a new profile, right?

I can choose D50 as the white point in OptiCAL and on the following screen shot you can see which measurements OptiCAL can give me: <http://home18.inet.tele.dk/madsen/monitor/optical.gif>

Regards
Madsen.
M
Madsen
Feb 4, 2004
Greg wrote:

Good – you can get xyY readings, so just display a patch of full scale red, green, and blue, and take the respective spot measurements in xyY. Don’t bother about re-calibrating or re-profiling yet.

Ok. This is what I get on my LCD with the settings I normally use: <http://home18.inet.tele.dk/madsen/monitor/spot_measurements>

The Trinitron chromacities don’t really look correct to me, particularly the red and green.

I’ve often wondered about the strange looking gamut of my CRT compared to other monitor profiles, so maybe you’re right that there’s something wrong with that. I’ll have a look at it later…


Regards
Madsen.
G
Greg
Feb 4, 2004
Thomas,
Thanks for doing the reading. I think it looks ok – it matches reasonably closely to the value in your
x,y diagram, and also Viewsonic’s ICC profile for that display.

I’ve had yet another look at the Trinitron chromacities. They’re not *way* off, but they
do seem *slightly* too far off for comfort. I’ll be interested in your spot reading results.

I have to wonder whether we’re really gaining anything by using our relatively inexpensive
colorimeters to measure the chromacities. Can we really measure them accurately enough? I just
wonder whether we’d be better off just manually entering the manufacturer’s data,
if we have the information, and just use the colorimeters to help set the whitepoint, brightness
and contrast, and create accurate gamma correction curves.

Greg.

"Thomas Madsen" wrote in message
Greg wrote:

Good – you can get xyY readings, so just display a patch of full scale red, green, and blue, and take the respective spot measurements in xyY. Don’t bother about re-calibrating or re-profiling yet.

Ok. This is what I get on my LCD with the settings I normally use: <http://home18.inet.tele.dk/madsen/monitor/spot_measurements>
The Trinitron chromacities don’t really look correct to me, particularly the red and green.

I’ve often wondered about the strange looking gamut of my CRT compared to other monitor profiles, so maybe you’re right that there’s something wrong with that. I’ll have a look at it later…

Regards
Madsen.
M
Madsen
Feb 4, 2004
Oh my god! I haven’t used my CRT for weeks. It’s amazing to see how fuzzy it is when your eyes are used to a crystal clear LCD, but that’s another topic I guess. 🙂

Greg wrote:

Thanks for doing the reading. I think it looks ok – it matches reasonably closely to the value in your x,y diagram, and also Viewsonic’s ICC profile for that display.

If I compare my custom made OptiCAL profile for my Viewsonic LCD with the canned profile from Viewsonic, I see a huge difference when viewed in iccProfileViewer:
< http://home18.inet.tele.dk/madsen/monitor/custom_versus_cann ed.jpg> (‘VP201s’ is the custom made. ‘VP201s fra Viewsonic.icm’ is the canned one).

I’ve had yet another look at the Trinitron chromacities. They’re not *way* off, but they do seem *slightly* too far off for comfort. I’ll be interested in your spot reading results.

You can see them here:
< http://home18.inet.tele.dk/madsen/monitor/spot_measurements/ sony>

The result in iccProfileViewer with the newly made Sony profile is pretty much the same as before:
< http://home18.inet.tele.dk/madsen/monitor/viewsonic_versus_s ony.jpg>

It seems that the calibration is pretty accurate according to OptiCAL:
<http://home18.inet.tele.dk/madsen/monitor/calibration/sony/>

I have to wonder whether we’re really gaining anything by using our relatively inexpensive colorimeters to measure the
chromacities. Can we really measure them accurately enough?

That’s a good question.


Regards
Madsen.
G
Greg
Feb 5, 2004
"Thomas Madsen" wrote in message

Greg wrote:

Thanks for doing the reading. I think it looks ok – it matches reasonably closely to the value in your x,y diagram, and also Viewsonic’s ICC profile for that display.

If I compare my custom made OptiCAL profile for my Viewsonic LCD with the canned profile from Viewsonic, I see a huge difference when viewed in iccProfileViewer:
< http://home18.inet.tele.dk/madsen/monitor/custom_versus_cann ed.jpg> (‘VP201s’ is the custom made. ‘VP201s fra Viewsonic.icm’ is the canned one).

This is a bit strange, because the chromacities in the diagram, for the canned profile,
don’t seem to match the chromacities I computed from the ICC file itself. There may be some kind of whitepoint adaptation going on which changes the actual values which that profile comparer displays on the diagram. Not sure. Or perhaps the profile I downloaded is different to the one you are using? (I don’t have access to the profile at the moment, and I can’t remember where I obtained it, either – I did a web search for "VP201s" and found the driver pretty quickly that way – I installed the driver to get the profile)

It seems that the calibration is pretty accurate according to OptiCAL:
<http://home18.inet.tele.dk/madsen/monitor/calibration/sony/>

That doesn’t have anything to do with the accuracy of the chromacity measurements though. All that display is showing is how well the desired tonal response was achieved.

Greg.
M
Madsen
Feb 5, 2004
Greg wrote:

Or perhaps the profile I downloaded is different to the one you are using?

The profile I have, came with the monitor. You can get it here: <http://home18.inet.tele.dk/madsen/monitor/vp201s/canned.icm>

This is my OptiCAL profile for the same monitor:
<http://home18.inet.tele.dk/madsen/monitor/vp201s/vp201s.icm>

It seems that the calibration is pretty accurate according to OptiCAL:
<http://home18.inet.tele.dk/madsen/monitor/calibration/sony/>

That doesn’t have anything to do with the accuracy of the chromacity measurements though.

No, I’m aware of that. My intention was just to illustrate that the desired gamma and white point setting was reached before I profiled it.


Regards
Madsen.
G
Greg
Feb 6, 2004
"Thomas Madsen" wrote in message
The profile I have, came with the monitor. You can get it here: <http://home18.inet.tele.dk/madsen/monitor/vp201s/canned.icm>

The currently available profile from the Viewsonic web site has different chromacities. http://www.viewsonic.com/support/drivers.htm The blue cooradinates seem to differ the most, and the new coordinates are closer to yours. However, there still seems to be a bit of a discrepancy for the green and red coordinates. It looks to me like your colorimeter *may* not be quite as accurate as the Eye One Display puck. (any chance of borrowing an Eye One Display, or better yet, a really good quality emissive spectrophotometer?) I think your Trinitron measurements are also a bit out.

Greg.
G
Greg
Feb 6, 2004
Thomas,
I just calculated the colour difference (dE) between the two reds (yours, and Viesonic’s profile),
after scaling the luminance to match. The result is 26, which is a large difference indeed. (considering that we can *just* detect a dE of 1) I did this to get some sense of the perceptual magnitude of these chromacity discrepancies.

So I think these discrepancies really do make a difference. As to which is more accurate, your mesasurement, or the manufacturer’s profile data, I really don’t know.

Greg.

"Greg" wrote in message
"Thomas Madsen" wrote in message
The profile I have, came with the monitor. You can get it here: <http://home18.inet.tele.dk/madsen/monitor/vp201s/canned.icm>

The currently available profile from the Viewsonic web site has different chromacities. http://www.viewsonic.com/support/drivers.htm The blue cooradinates seem to differ the most, and the new coordinates are closer to yours. However, there still seems to be a bit of a discrepancy for the green and red coordinates. It looks to me like your colorimeter *may* not be quite as accurate as the Eye One Display puck. (any chance of borrowing an Eye One Display, or better yet, a really good quality emissive spectrophotometer?) I think your Trinitron measurements are also a bit out.

Greg.

M
Madsen
Feb 6, 2004
Greg wrote:

So I think these discrepancies really do make a difference. As to which is more accurate, your mesasurement, or the manufacturer’s profile data, I really don’t know.

I can’t imagine that the profile from Viewsonic describes _my_ LCD very accurate. It can’t be much more than a common denominator for every VP201s out there, as I see it, but you’re right that the difference between my custom made profile and the canned one from Viewsonic is quite large.

Maybe you’re right that my colorimeter isn’t very accurate. Unfortunately, I don’t have access to another colorimeter (or spectrophotometer), but if I stumble over someone I can borrow one from, I’ll give it a try.

OptiCAL supports the following sensors, by the way:
< http://home18.inet.tele.dk/madsen/monitor/optical/sensors.gi f> I don’t know which of the supported sensors that are good or bad. As far as I know, the Xrite DTP92, has a quite good reputation(?).


Regards
Madsen.
M
Madsen
Feb 7, 2004
Greg wrote:

However, there still seems to be a bit of a discrepancy for the green and red coordinates. It looks to me like your colorimeter *may* not be quite as accurate as the Eye One Display puck.

It could also be a bug in the software from Colorvision, according to Ian Lyons.

<http://www.computer-darkroom.com/optix/optix_2.htm> | The colour gamut and in particular the chromacity values of the | profiles obtained from each of the systems mentioned above shows | that MonacoOPTIX profiles compare very favourably with those from | the more expensive Eye-One spectrophotometer. Both Spyder bundles | appear to produce profiles with different chromacity values, which | tend to result in more emphasis on blue/cyan and less on | green/reds. My initial impressions having compared how all four | systems reproduce a range of images was that they are all equally | good. However, a more detailed analysis of each application | suggests that MonocoOPTIX is in fact producing very similar | profiles to Eye-One, and that these profiles are more accurate | than those obtained from either Spyder bundle. The numerical | differences might appear small but the effect of the chromacity | discrepancy is clearly visible when a digital version of the | GretagMacbeth ColorChecker chart is viewed with my Apple Cinema HD | Display. The Spyder based profiles have reproduce blue and cyan | much stronger, but they aren’t an accurate representation of the | ColorChecker. The advantage provided by the Apple display for this | comparison is the fact that the profiles are all based upon | exactly the same display settings (i.e. there is nothing to change | so nothing should be different). I repeated the above test with | two other Spyders and a Mitsubishi CRT with similar results, which | leads me to believe that there is a bug in the current version of | both ColorVision applications.


Regards
Madsen.
G
Greg
Feb 7, 2004
Thomas,
Very interesting. So why does Ian Lyons suspect the software, and not the Spyder itself?

Greg.
"Thomas Madsen" wrote in message
Greg wrote:

However, there still seems to be a bit of a discrepancy for the green and red coordinates. It looks to me like your colorimeter *may* not be quite as accurate as the Eye One Display puck.

It could also be a bug in the software from Colorvision, according to Ian Lyons.

<http://www.computer-darkroom.com/optix/optix_2.htm> | The colour gamut and in particular the chromacity values of the | profiles obtained from each of the systems mentioned above shows | that MonacoOPTIX profiles compare very favourably with those from | the more expensive Eye-One spectrophotometer. Both Spyder bundles | appear to produce profiles with different chromacity values, which | tend to result in more emphasis on blue/cyan and less on | green/reds. My initial impressions having compared how all four | systems reproduce a range of images was that they are all equally | good. However, a more detailed analysis of each application | suggests that MonocoOPTIX is in fact producing very similar | profiles to Eye-One, and that these profiles are more accurate | than those obtained from either Spyder bundle. The numerical | differences might appear small but the effect of the chromacity | discrepancy is clearly visible when a digital version of the | GretagMacbeth ColorChecker chart is viewed with my Apple Cinema HD | Display. The Spyder based profiles have reproduce blue and cyan | much stronger, but they aren’t an accurate representation of the | ColorChecker. The advantage provided by the Apple display for this | comparison is the fact that the profiles are all based upon | exactly the same display settings (i.e. there is nothing to change | so nothing should be different). I repeated the above test with | two other Spyders and a Mitsubishi CRT with similar results, which | leads me to believe that there is a bug in the current version of | both ColorVision applications.


Regards
Madsen.
M
Madsen
Feb 7, 2004
Greg wrote:

So why does Ian Lyons suspect the software, and not the Spyder itself?

Maybe he have tried the same software with another colorimeter (or spectrophotometer) and found the same inaccuracy, but I don’t know.

I’ve found another article:

<http://www.drycreekphoto.com/Learn/monitor_calibration.htm> | The Spyder profile overestimates the display performance in some | areas and underestimates in others. The problem is most visible | in darker, saturated red colors. This is likely a combination of | lack of sensitivity in the Spyder and software biased for speed of | profiling over full accuracy.

And further down on the page, you’ll find:

| For illustration, below is a comparison of white and neutral tones | that the Spyder and Spectrolino produced for monitor profiles. | The background color is the desired set point (white = 255/255/255, | mid-tone gray = 127/127/127). The measurement patches from the | Spectrolino were accurate to within 1 RGB point – likely roundoff | error – while the Spyder produced a slight color cast. The results | were measured using a Spectrolino. The cast produced by the Spyder | was difficult to detect without an absolute reference to compare | with. Comparing a $300 Spyder to an instrument costing twenty | times as much is admittedly unfair, but it shows the difference | top-notch hardware can make. Results from an Eye-One should be | very comparable to those obtained using the Spectrolino.

Hmm, maybe I should buy an Eye-One instead.
I definitely miss a package that can produce printer profiles for my Epson Stylus Photo 2100/2200, so at the moment I drool over the Eye-One Publish package. But I could also use a package that can profile a Textronix Phaser 780 color laser, and I’m not sure if I can do that with the Eye-One Publish package. Maybe I should look at the Eye-One Pro package instead. It’s expensive, but seems to be _very_ versatile.


Regards
Madsen.
F
Flycaster
Feb 7, 2004
"Thomas Madsen" wrote in message
[snip]
Hmm, maybe I should buy an Eye-One instead.
I definitely miss a package that can produce printer profiles for my Epson Stylus Photo 2100/2200, so at the moment I drool over the Eye-One Publish package. But I could also use a package that can profile a Textronix Phaser 780 color laser, and I’m not sure if I can do that with the Eye-One Publish package. Maybe I should look at the Eye-One Pro package instead. It’s expensive, but seems to be _very_ versatile.

Thomas, for just the monitor and any RGB driver controlled printer (eg, 2100/2200), the EyeOne package you want is the "Photo" – about $1200 on the internet. Separate modules can be puchased later at very little mark-up if you need them.

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M
Madsen
Feb 7, 2004
Flycaster wrote:

Separate modules can be puchased later at very little mark-up if you need them.

Ok and thanks. Maybe I’ll start with the Photo-package then.


Regards
Madsen.

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