Hi Linelle
You’ve kind of stumbled into a working scenario. Your assign, then edit workflow is useable, but not the best way to get from A to B. Ideally, you should correct your image in a ‘working space’ such as AdobeRGB. When you have an image you’re happy with and ready to print, *convert* to your Canon profile. After this conversion you could do a few more small edits if you like.
What is happening? Always remember – assigning a profile only describes the colors. It does not change them within the file. By assigning the printer profile you are telling the monitor (and all the color gears inside your computer) to show you how the colors appear in the Canon’s color world, or in the Canon’s language of sorts. When you edit with the Canon profile assigned, you are speaking its language and it happily gives you what you saw on your calibrated screen. So what is the problem? Well, the file you’ve so carefully tweaked for your printer is now just that – a file ONLY for your printer. Take that same image to an Epson and suddenly you’ll find yourself making even more edits to get the colors back to how you want! This will most likely create trouble, both technically (you can only pull those pixels so much!) and psychologically. The good news? This is why we convert.
By working in a standard working space (AdobeRGB, sRGB, ColorMatch, ECIRGB, ProPhoto) you are creating a device independent file – one that is portable. Converting from this device-independent, portable, master file essentially does the work for you. The converstion translates the color numbers from your file to the ‘language’ of the printer. The idea is that, given good output profiles, you could print your master image to 20 different printers and get the same colors out in the end.
In your situation, you see how much easier it was just to convert and print. Your colors were translated *by Photoshop* from the photo’s space to the printer space rather than *you* doing all of the work in the printer space. Hope that makes the lightbulb turn on!
Scott
I tried *assigning* the Canon profile and the image appeared on my monitor washed out. So I made my corrections and then it printed out perfectly. However, if I take the same image and *convert* to the Canon profile, it looks virtually the same as when opened in PS, i.e., not washed out.
Linelle Lane wrote:
Like many others, I’m struggling with color space concepts. I read all I can on the topic, but mastery still seems just beyond my grasp.
The way of the color jedi: walked this path many have.
But I do have a specific question right now. I have a Canon i9100, which has great-looking output. I use Photoshop 7 at home and CS at work. My monitors have been calibrated with Adobe Gamma, as it’s the best I can do for now.
Nothing wrong with Adobe Gamma – stick with it and don’t worry about colorimeters. Although important in a production workflow, they are almost useless for a single person setup. Their main function is to keep you out of trouble (gambling, liquor, drugs, and so forth) by reducing your money supply.
Originally when I printed my digital photos,
the i9100 output seemed washed out.
If you simply print your image with no color setup, Canon printers, along with most other printers, will print a given image somewhat lighter than a PC monitor will display it.
Then I tried *assigning* the
Canon profile and the image appeared on my monitor washed out.
Yes. The profile is doing exactly what the printer does: displaying your images brighter. Assigning a profile tells Photoshop "the color numbers in this image are intended for my Canon printer, so please display them lighter than you would a normal image".
So I
made my corrections and then it printed out perfectly. However, if I take the same image and *convert* to the Canon profile, it looks virtually the same as when opened in PS, i.e., not washed out.
Converting a profile tells Photoshop to do two things: "1) please translate the colors in this image so that they will print correctly on my Canon printer, and 2) remember you did this so that you may display them correctly on my monitor". Because of #2, converting normally produces very little change in image appearance.
I’m confused. Should I *assign* and edit, or *convert*?
Converting to your printer profile is the wrong answer. Assign and edit is better, as demonstrated by the fact that it worked for you. but there is third and better way.
That better way is to use a working space (normally sRGB or perhaps Adobe RGB) for editing your images, and use printer color management when printing. If you have assigned the Canon profile to your printer (via the color management tab in your printer settings) everything will work as it was designed.
There are several ways to mess up your color settings. I generally recommend Ian Lyon’s web page for clear instructions on how to set up your color management. Follow these instructions in detail and you’ll be fine. The relevant articles for PS7 are:
http://www.computer-darkroom.com/ps7-colour/ps7_1.htm http://www.computer-darkroom.com/ps7_print/ps7_print_mac.htm For good measure, should you get to the point where finer adjustment is important, here is a test strip to check your printer for color casts and shadow and highlight detail, as well as flesh tones:
http://www.curvemeister.com/downloads/TestStrip/digital_test _strip.htm —
Mike Russell
www.curvemeister.com
www.geigy.2y.net
"mmm" wrote in message
Hello Linelle,
Please forgive a newbie’s intrusion into this thread, but I’m a bit confused by some of the replies and wasn’t sure where best to add this comment. I don’t think I’m as far down the track as you in understanding these issues.
I thought that one of the major uses of color profiles was to give one the ability to produce a file in a (usually standard) color space and have the associated software/drivers convert the file for output, such that outputs (e.g. via monitor, printer 1, printer 2) were as close to each other as possible. Again I thought the idea was that this could be done without further editing??
3 notes (caveats?)
1. The file is being viewed as intended (video and monitor correctly set up – calibrated, correct profile, environment issues taken into account)
2. A device’s output is consistent with it’s profile (printer
calibration?)
3. You accept that you are limited to the intersection of the color spaces of the working file and output device. (I think!)
So I’m confused now with the need to edit (i.e. color correct) a file to match different output devices. Sorry to be so slow on this. I’d appreciate any comment showing where I’m missing the point here as there’s obviously something I haven’t grasped.
Mark
Linelle Lane wrote:
Like many others, I’m struggling with color space concepts. I read all I
can
on the topic, but mastery still seems just beyond my grasp.
But I do have a specific question right now. I have a Canon i9100, which
has
great-looking output. I use Photoshop 7 at home and CS at work. My
monitors
have been calibrated with Adobe Gamma, as it’s the best I can do for
now.
Originally when I printed my digital photos, the i9100 output seemed
washed
out. Then I tried *assigning* the Canon profile and the image appeared
on my
monitor washed out. So I made my corrections and then it printed out perfectly. However, if I take the same image and *convert* to the Canon profile, it looks virtually the same as when opened in PS, i.e., not
washed
out.
I’m confused. Should I *assign* and edit, or *convert*?
Mark, welcome to the thread! The more the merrier! And it sounds like you’re about as far along as me anyway. I initially was confused about the difference between assign and convert profile. Originally if I edited my image and printed to my Canon i9100, it would appear washed out. If I assigned my printers profile, it would appear washed out on my monitor, but *exactly* as it printed. Aha, I thought. I’ll do this, edit the image to how I want it to look and it will print as I want. It does, but then I’m left with an image that is screwed up for other output devices, including viewing on my monitor.
So, if I understand *some* of the good people here (not all seem to agree, but hey, what’s new?), I should work in the, say, Adobe RGB color space, and edit my image till it seems right. Then, I convert to my printer profile, so that my colors remap correctly for my output device (printer). Hope I have that right.
This leads me to another question. When I print (after converting to my printer’s profile), do I let my printer take charge, rather than letting Photoshop color manage?
Johan W. Elzenga wrote:
Linelle Lane wrote:
This leads me to another question. When I print (after converting to my printer’s profile), do I let my printer take charge, rather than letting Photoshop color manage?
Because your image is already in the color space of the printer, the logical next step is as follows: Use Photoshop’s color management, so turn OFF printer color management. In Photoshop, use "Document" as source space, and "Same as source" as printer space.
I don’t think so. The images don’t have the color space of the printer. For one thing that would screw up the color on the monitor. The color space in the image is really not for the printer or the monitor; it’s just a reference point.
Your color management system has to be able to translate from that reference point to various devices that this image will be sent to. The first place it translates to is the monitor. That’s why you have to have your monitor reasonably calibrated. If it isn’t then you aren’t going to edit the colors to look right. However, the monitor reference point is still different than the one in the image; you don’t assign the monitor profile to your image.
sRGB was designed to be close to the "average" CRT monitor. That doesn’t mean that it really is the same as your monitor. That also doesn’t mean that your files have to be in sRGB to work on a monitor. AdobeRGB is a broader color space that defines more colors. (There are even broader ones.) Yes, you may not be able to see all those colors on your monitor, but they might be useful in your color editing. In either case, you still save it the same when you are done editing.
This isn’t anywhere near the printer’s color space. For one thing, your printer is probably CMYK and not RGB. It could be CcMmYK or CMYKpRBg (like my R800) or something else. There aren’t any consumer RGB printers so your sRGB or aRGB color spaced images can NOT be in the same color space as the printer.
Then again, it’s not relevant. As long as the color management system is working from known reference points for every device, it can translate properly. So, the color space in the file is a known reference point. Your calibrated monitor is a known reference point. The odds are that you printer maker has build the known color reference points into the printer driver.
Of course, they tend to build known reference points into the drivers FOR ONLY THEIR PAPERS. This can screw up things if you use other papers. This is called introducing unknown reference points into the equation. The proper thing to do in that case is to calibrate the printer driver (or just the color parts) for the new variables. This can be complicated or cost money and is outside the scope of this message.
OK, what do you use to do the translating from one reference point to another? You have two either/or choices. You can use Photoshop or your OS’s color management system. Both OS X and XP will do this just fine in conjunction with the printer drivers. Photoshop will also do it just fine. However, you do NOT want both of them working. So, you have to tell Photoshop NOT to use one of them.
A lot of people recommend turning off the printer’s color management (part of the OS) and using Photoshop’s to do it all. This works particularly well when the printer drivers are only so-so. I like to use the printer’s color management because my Epson R800 driver is pretty darn good. It also leaves me a tad more flexibility for printing on multiple printers. In reality, it’s 6 one way and half a dozen the other.
Therefore, (back to the thread) assigning a profile to an image that already has one will throw off the color reference point that was already in place. Logically, you should only use "assign" when there is no profile in place. Converting the profile will use either the OS or Photoshop to actually change the color reference point of the image.
So ends Clyde’s little lesson on color management.
Clyde
Hi All!
First of all I say: very informative and interesting thread. I thank all contributors and thank OP. Also, I would highly appreciate correcting me for what I wrote here, as I am not a real color profile expert.
After many years with Photoshop and other design software, I still find it really challenging and difficult to scrutinize the various aspects of color profiles. Maybe many people will give better idea about the correct method for dealing with a deceptive topic like color profiles. However, I will mention some facts that I learnt during my work:
The first and basic fact that stands behind all implications of profiles is the following:
RGB (Red Green Blue) are the waves of light (I even do not prefer to call them colors, as the case with printed inks). They are of additive nature, i.e. if the values of RGB are (0,0,0)-RGB then it is Black or more precisely a BLACKOUT. Practically (0,0,0)-RGB means that no light is coming at all or the bulb is OFF. On the contrary (255,255,255)-RGB or more precisely (100%,100%,100%)-RGB will yield WHITE light, given the medium is originally black like a dark room or even a COMPUTER’S MONITOR. On the contrary, CMY (Cyan Magenta Yellow) are the inks which reflect light, so they are the printable colors. CMY are of subtractive nature, i.e. if the values of CMY are (0,0,0)-CMY then actually they represent no color at all. If no ink was printed on a white paper, then the area is white. On the contrary
(100%,100%,100%)-CMY will produce Black (in theory). RGB is the complement or mirror system of CMY. For example, in theory (20%,30%,40%)-RGB (or about (51,77,103)-RGB on 256 scale) should be printed, in theory as (80%,70%,60%)-CMY.
However, for the reason of impurities that can be found in those inks, (100%,100%,100%)-CMY may only produce muddy black, or more visibly a very deep brown. So, Black ink is printed separately to compensate for printing three inks to get a single faux Black. The idea of using the Black, while not being a basic color, has led to the ideas of using further spot colors (see below) to compensate for faint tints in printing. This leads us to a fact that the only color which has equal values in both RGB and CMY systems is the (50%,50%,50%)-RGB (i.e. (127,127,127)-RGB) and (50%,50%,50%)-CMY which is the Gray color. But we have to understand that the first Gray is a LIGHT that may illuminate darkness, and the second gray is an ink that can reflect light. This is why we calibrate the screen using a Adobe Gamma. Adobe Gamma will help us realize a suitable balance between the gray we see like a light and the gray we see printed; thereby, define a point of reference for what we call it Gray in RGB system. This point of reference will, theoretically, lie in the middle of RGB scale. However, practically IT WONT. So, the Gray for a certain monitor is (127,129,128)-RGB and (128,127,130)-RGB for another monitor. The shifting percentage is the calibration done by the color profile. So, we will be in need of a printer calibration (profile) that will respond to the RGB reference point. That profile will interpret RGB values into printable CMY values and should be able to decide when to use the Black ink (in simple printers), and/or other spots like Orange, Green, Light Cyan, Light Magenta, (in more complicated printers), such that it prints the widest possible spectrum. For the reason of the nature of light, RGB (lights) will NEVER be the same colors printed on a printer, however, they will closely resemble them, in certain lighting conditions. Other reasons why printed colors cannot be the same as the monitor colors could be the paper’s native color, ink purity, paper’s roughness, press blanket pressure, etc.
According to the above, I advise of the following:
1- MONITOR CALIBRATION: Calibrate your monitor using Adobe Gamma and pay a lot of attention to see which gray is the best neutral gray. If you don’t know how calibrate your monitor, hire someone to do it for you! It is a crucial step.
2- WHICH PROFILE? Some people will advise you to use so and so. The golden rule DON’T trust anyone nor trust YOUR instinct, nor trust ready-made profiles (that were done in laboratory ideal conditions)! Trust the real experiments! Remember that profiles are nothing but calibration tables. So, if you refer to the scanners manual and you were advised of using a certain profile, DO NOT quit trials with other existing profiles you have. Take some time with your scanner and printer and make various experiments. First try NO PROFILES. Then try with the profiles included with the scanner and the printer. Then try some other well-known profiles. Eventually you will reach at satisfactory results. Remember: what you see on monitor (soft proof) is always brighter than hard proof. If you suspect scanner’s profile that ships with the scanner, just use AUTO COLOR feature in Photoshop, then do a visual comparison with the scanned image. Use other tools (as needed).
3- OFFSET PRINTING: Having calibrated your monitor by using Adobe Gamma, you have to stick to work in CMYK space. Photoshop’s native CMYK will always make you sure that the color values input by hand will remain to the end this way! So DO NOT USE ANY PROFILES for offset printing. Discard all profiles, and correct colors manually before you ship your final publication to separation shop. However, you will need to decide the Black generation process. Black generation is crucial for good offset printing. UCR will be used to compensate the gray shades composed of equal amounts of CMY with a black tint only. Whereas, GCR does wider substitution for different amounts of CMY. Some paper types will highly absorb ink and make the PostScript dot more spreading, and therefore; we should decrease the ink, hence, increase the Dot Gain. (Refer to Photoshop online manual for more information). If you want to output CMYK image to a printer, then it is better you choose Printer’s Color Management. But when the matter comes to output separation films you actually need NO PROFILE tagging if you worked in CMYK from the beginning to the end.
4- CMYKOG and CMYKLcLm: CMYKOG
(Cyan-Magenta-Yellow-blacK-Orange-Green) and CMYKLcLm
(Cyan-Magenta-Yellow-blacK-Light cyan-Light magenta) are two spaces of hexachromatic nature (i.e. six colors process). Both spaces are used on the Large-Format printer. CMYKOG (erratically called this way though sequence of lithographic plates puts Black last) is used in offset printing and pigment-based inks, while the CMYKLcLm is used with dye-based inks on Large-Format Printers. Apparently, color profiles are indispensable to coordinate the roles of all the six inks. The idea behind the six colors is that additional colors are used to output faint tints. Just imagine a green of (6-0-6-0)-CMYK to be offset printed. It will look like a faint thing! What if we used a 20% tint of a premixed (spot) green (30,0,30,0)-CMYK, that would blend seamlessly with the image and the screens output in the lithographic films was 20% density? Of course this would be delightful, and there will be a chance to simulate more of the RGB space. Details of faint tints substitution are much like having a Transfer Function (like that used in Photoshop) that will tell the printer about the generation of the dot currently in print. In case of color separation, lithographic films will be generated according to the real pixel values assigned by the designer (in Photoshop’s CMYK space) OR the SHIFTED pixel values generated by Color Profile. Most of us will NOT be 100% sure on which image setter the artwork will be separated, so there should be some machine-independent procedure for the color profiles. Native CMYK space of Photoshop is always excellent, if and only if we determine how much the dot gain in the conditions of printing press.
FINAL WORD: The designer is completely responsible for any negative changes that occur because of downsampling from RGB to CMYK. Before separation, the designer should have the client’s cursive approval on the final hard copy of the design.
Mohamed Al-Dabbagh
Senior Graphic Designer
From: "Linelle Lane"
I have been using Canon Photo Paper Pro … I haven’t seen any profiles for that paper.
Canon is lax about supplying ICC profiles for its papers, which is one of the reasons it trails Epson so badly in the desktop inkjet market among photographers. I’ve seen some 3rd party ones floating around though.
I just assume the i9100 "knows" this paper and how to print optimally to it.
Usually this is hidden from the user, buried in the printer driver software. You can bypass the ICM flow with the Epsons too, that’s what most low-level users who aren’t using ICM do.
There are a couple of advantages to using the ICM flow — first you can soft-proof accurately (if you have a good monitor profile and accurate printer profiles) and make adjustments earlier in the flow, second you can generate your own profiles if you have the right software/hardware calibration package and get better results than relying on the canned generic profiles, which are rarely optimized for a consumer printer due to the variance between units.
If I were to buy a particular kind of paper (with a profile), how would it know what printer I was using?
Each printer, paper and ink combination should have a unique profile generated for it. At a minimum the profile should be for a specific model of printer (as opposed to a specific unit, which would be ideal) with a specific paper and ink, or the supplier is just playing games.
I’m just guessing that the same AdobeRGB photo would look different when printed on different printers using the same paper.
True.
So, while this explanation sounds simple (and many concur), I don’t quite understand the logic of it.
Basically each printer/paper/ink has a range of colors it can print. With this ICM flow you’d print out a test pattern and measure the actual colors produced by the printer, then software will create what’s essentially a giant look-up table (the ICM profile) so that when your file has a certain color represented by the RGB value the software will translate to the best match for your printer so you get the most accurate colors in your print.
Here’s a pretty good explanation of the basics of the ICM flow (how the RGB triplets get changed to try to match the colors) and on soft proofing …
http://www.creativepro.com/story/feature/13605.html http://www.creativepro.com/story/feature/10150.html?origin=s tory Bill
