Purple fringing in digital images

Rick wrote:

I take mostly landscape phots with my Canon A70 and tend to get a lot of purple fringing around trees etc. Is there and easy way to fix this this in Photoshop 7?
RickB

This is not easily fixable in Photoshop without a specialist plugin aimed at that particular problem. I used a program called jpginst.exe for a while and there are many other jpg enhangement programs around intended to ‘fix up’ fringing and colour casts. Your milage may vary so don’t buy till you try!

Douglas

Rick wrote:

I take mostly landscape phots with my Canon A70 and tend to get a lot of purple fringing around trees etc. Is there and easy way to fix this this in Photoshop 7?
RickB

I was to lazy to check if the Canon you have outputs RAW files. If id does enter "Chromatic" in the search field of your help file and read the "Compensating for chromatic aberration" part

If you don’t have CS or you have CS but no RAW files check this out: www.caldwellphotographic.com/TutorialsDistortionAndColorFrin ging.html or
http://tinyurl.com/hnl8
You’ll have to locate PanoTools, harder since the bastards at Ipix have forced Prof. Dersh to stop offering it.If you can’t find it let me know here Stephan

Newsreader: Microsoft Outlook Express 6.00.2900.2180
On Sat, 13 Nov 2004 21:16:43 -0800,
"Rick" wrote this message:

I take mostly landscape phots with my Canon A70 and tend to get a lot of purple fringing around trees etc. Is there and easy way to fix this this in Photoshop 7?

Fiddaman’s plugins
http://www.sd3.info/pf828/index.html
Free Photoshop Plugins
Purple fringe reduction, shadow and highlight adjustment, color & BW luminance adjustment, and other tools.

/CoMa

—
Conny (CoMa) Magnusson

http://www.algonet.se/~hubbabub/
ICQ : 1351964
=============================
At such times, us wise Cats retire to meditate…

Newsreader:
On Sun, 14 Nov 2004 16:15:48 +1000,
"Douglas MacDonald" wrote this message:

I used a program called jpginst.exe
for a while and there are many other jpg enhangement programs around intended to ‘fix up’ fringing and colour casts.

Did you mean this program,
when you said "jpginst.exe"
Jpeg Enhancer
http://www.vicman.net/jpegenhancer/

/CoMa

—
Conny (CoMa) Magnusson

http://www.algonet.se/~hubbabub/
ICQ : 1351964
=============================
I’ve got to go have my pacemaker checked,
it has been so exciting talking to you

I know this is a Photoshop newsgroup, but I use Paint Shop Pro 9 for correcting both CA and Digital Camera Noise, both of which I have not been able to duplicate the correction level in Photoshop.
"Rick" wrote in message

I take mostly landscape phots with my Canon A70 and tend to get a lot of purple fringing around trees etc. Is there and easy way to fix this this in Photoshop 7?
RickB

In article , Tracy Pori wrote:

I know this is a Photoshop newsgroup, but I use Paint Shop Pro 9 for correcting both CA and Digital Camera Noise

On its own or with plug-ins?

Many of these will work with Photoshop, so we’re not off-topic. 😎

—

Roger

Rick,

Here’s a technique that I found on the net and then tried with success. It can’t hurt for you to try.

1. Convert image to Lab Mode;

2. Select a and b channels only

3. Apply dust and scratches filter (say radius about 7-15)

4. Convert back to RGB

That’s it! I have to admit that I really can’t explain why it works, but it does – at least to significantly reduce the purple fringe.

John

"Rick" wrote in message

I take mostly landscape phots with my Canon A70 and tend to get a lot of purple fringing around trees etc. Is there and easy way to fix this this in Photoshop 7?
RickB

Nope all on it’s own.
"Roger Whitehead" wrote in message

In article , Tracy Pori wrote:

I know this is a Photoshop newsgroup, but I use Paint Shop Pro 9 for correcting both CA and Digital Camera Noise

On its own or with plug-ins?

Many of these will work with Photoshop, so we’re not off-topic. 😎
—

Roger

Purple fringing is not caused by jpg compression. It is usually caused by poor camera optics. If you just want to get rid of the purple fringing then load your image in to Photoshop make a duplicate layer of it above the original image layer. Now you can either apply enough Gaussian Blur to kill the purple color or you can go in with the eye dropper tool and sample colors and then use a paint brush to paint over the purple with the right color. I find the blur easiest. Once you have that done change the altered layers blending mode to color. This merges it with the bottom layer. Basically the bottom layer provides the details and the altered top layer provides the color.

John

"Douglas MacDonald" wrote in message

Rick wrote:

I take mostly landscape phots with my Canon A70 and tend to get a lot of purple fringing around trees etc. Is there and easy way to fix this this in Photoshop 7?
RickB

This is not easily fixable in Photoshop without a specialist plugin aimed at that particular problem. I used a program called jpginst.exe for a while and there are many other jpg enhangement programs around intended to ‘fix up’ fringing and colour casts. Your milage may vary so don’t buy till you try!

Douglas

On Tue, 16 Nov 2004 17:12:20 GMT, "John Doe"
wrote:

Purple fringing is not caused by jpg compression. It is usually caused by poor camera optics.

Wrong. On digital cameras it’s caused by small CCDs.

—

Hecate – The Real One

veni, vidi, reliqui

Hecate wrote:

On Tue, 16 Nov 2004 17:12:20 GMT, "John Doe"
wrote:

Purple fringing is not caused by jpg compression. It is usually caused by poor camera optics.

Wrong. On digital cameras it’s caused by small CCDs.

Actually, it can be both. Small sensors can be a cause, but colour fringing can also be caused by the optics. Even using big sensors like the Canon 1Ds ‘full frame’ sensor you can see color fringing in the corners when a wide angle lens is used. In fact, the *big* size of the sensor is partly the problem, because light hitting the sensor under a steep angle it the main cause. The bigger the sensor, the steeper the angle. That’s why you only see the effect in the corners of the image, not in the centre.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/

On Wed, 17 Nov 2004 01:15:58 +0000, Hecate wrote:

Would it be alright to divert this thread into a discussion on digital cameras ? I’m looking for one that I can keep in my truck for that last minute photo ‘a Kodak moment’ where you never have a camera available. I’ve already asked in several camera groups, and have picked up some good leads, but obviously whatever I get should be editable in PS8.
I haven’t even thought to look and see what PS8 says about digital cameras. Are there any specifically supported by PS?

On Tue, 16 Nov 2004 17:12:20 GMT, "John Doe"
wrote:

Purple fringing is not caused by jpg compression. It is usually caused by poor camera optics.

Wrong. On digital cameras it’s caused by small CCDs.

—

Hecate – The Real One

veni, vidi, reliqui

—
more pix @ http://members.toast.net/cbminfo/index.html

On Wed, 17 Nov 2004 10:42:28 +0100, (Johan W.
Elzenga) wrote:

Hecate wrote:

On Tue, 16 Nov 2004 17:12:20 GMT, "John Doe"
wrote:

Purple fringing is not caused by jpg compression. It is usually caused by poor camera optics.

Wrong. On digital cameras it’s caused by small CCDs.

Actually, it can be both. Small sensors can be a cause, but colour fringing can also be caused by the optics. Even using big sensors like the Canon 1Ds ‘full frame’ sensor you can see color fringing in the corners when a wide angle lens is used. In fact, the *big* size of the sensor is partly the problem, because light hitting the sensor under a steep angle it the main cause. The bigger the sensor, the steeper the angle. That’s why you only see the effect in the corners of the image, not in the centre.

Yes, true. But it’s still the sensor of course. And I take your point about the quality of digital camera lenses – it was just that poster seemed to think that it was only caused by lenses whereas it’s mostly caused by being digital ;’-)

—

Hecate – The Real One

veni, vidi, reliqui

On Wed, 17 Nov 2004 08:44:13 -0500, Husky wrote:

On Wed, 17 Nov 2004 01:15:58 +0000, Hecate wrote:

Would it be alright to divert this thread into a discussion on digital cameras ? I’m looking for one that I can keep in my truck for that last minute photo ‘a Kodak moment’ where you never have a camera available. I’ve already asked in several camera groups, and have picked up some good leads, but obviously whatever I get should be editable in PS8.

I haven’t even thought to look and see what PS8 says about digital cameras. Are there any specifically supported by PS?

Depends whether you’re looking for a camera which saves in RAW. If you are, you’re not really going to get too many choices of point and shoot. Virtually all those are jpg only or some jpg/tiff. AVCR (Adobe Camera RAW has filters for almost all RAW types and Adobe are constantly releasing new versions of ACR as new RAW types appear. Photoshop is not your problem 😉 Your problem is deciding on the camera size and quality level you are prepared to except, along with the lens quality and whether or not you’;re happy with a fixed lens or require a zoom. And then there’s the different camera options available, flash, and ….

Your best idea is to go away and think about exactly what you want from the camera to narrow the search down somewhat. 🙂

—

Hecate – The Real One

veni, vidi, reliqui

On Sat, 13 Nov 2004 21:16:43 -0800, "Rick"
wrote:

I take mostly landscape phots with my Canon A70 and tend to get a lot of purple fringing around trees etc. Is there and easy way to fix this this in Photoshop 7?
RickB

Try this :

http://www.shaystephens.com/ca-ps.asp

Pier
—
Pierre Wiget
http://www.pbase.com/pier
wigetp<REMOVE>@bluewin.ch

On Thu, 18 Nov 2004 01:35:03 +0000, Hecate wrote:

I haven’t even thought to look and see what PS8 says about digital cameras. Are there any specifically supported by PS?

Depends whether you’re looking for a camera which saves in RAW. If you

Actually I’ve never used any computer peripheral other than a printer. I got USB installed specifically cause every camera I saw had ‘requires USB port’ in the details. What I was referring to, is there some camera that PS8 imports directly from ie: fire up PS8, connect camera xxxx, select import from camera.

Since PS8 would be my primary program to fiddle with the shots taken, it only makes sense to narrow down my choices to cameras that PS8 already supports. That would be my 1st triage in cutting down the available cameras. That should be able to narrow the field to maybe 50 cameras ?
I just haven’t dug into PS8 enough to know anything about it and digital photos or digital cameras.

ie: Canon Mavica a camera I researched yesterday. It uses a 3 1/2 floppy vs digital memory or film. Fine till I saw the $600+ price tag.

I have a ton of blank floppies, so far can’t find anything under 1.44 meg to put on them.

This camera obviously wouldn’t directly interface with PS8. Then there’s the heat thing again. If I leave a floppy in the truck here in Florida it’d be worthless on the 1st 80 degree day. And the rest of the year till hurricane season is over.

I’m just figuring the less I have to remember to carry out to the truck, the better. I can remember to uninstall the batteries after every use and store them separately. Should help in keeping them alive.

But what I’m looking for I guess is info on cameras that PS8 doesn’t reject. Or even if the camera has any bearing at all on PS8 ?
—
more pix @ http://members.toast.net/cbminfo/index.html

Hecate wrote:

Purple fringing is not caused by jpg compression. It is usually caused by poor camera optics.

Wrong. On digital cameras it’s caused by small CCDs.

Actually, it can be both. Small sensors can be a cause, but colour fringing can also be caused by the optics. Even using big sensors like the Canon 1Ds ‘full frame’ sensor you can see color fringing in the corners when a wide angle lens is used. In fact, the *big* size of the sensor is partly the problem, because light hitting the sensor under a steep angle it the main cause. The bigger the sensor, the steeper the angle. That’s why you only see the effect in the corners of the image, not in the centre.

Yes, true. But it’s still the sensor of course. And I take your point about the quality of digital camera lenses – it was just that poster seemed to think that it was only caused by lenses whereas it’s mostly caused by being digital ;’-)

It’s a bit of a chicken and egg, really. I think the best way to discribe it would be "inadequate optics". A small sensor as such does not cause color fringing. But the smaller the sensor, the more it demands from the optics, so even good lenses can become inadequate for a particular sensor. So it’s not the sensor or the lens, it’s the combination that doesn’t match.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/

On Thu, 18 Nov 2004 09:06:07 -0500, Husky wrote:

On Thu, 18 Nov 2004 01:35:03 +0000, Hecate wrote:

I haven’t even thought to look and see what PS8 says about digital cameras. Are there any specifically supported by PS?

Depends whether you’re looking for a camera which saves in RAW. If you

Actually I’ve never used any computer peripheral other than a printer. I got USB installed specifically cause every camera I saw had ‘requires USB port’ in the details. What I was referring to, is there some camera that PS8 imports directly from ie: fire up PS8, connect camera xxxx, select import from camera.

Yes, all of them. But it’s a bad idea. A much better idea is to install a USB card reader (inexpensive and you get ones that will cover practically all card types) and leave that permanently attached to your computer. Give it a drive letter and all you do is take the card out of the camera, put it in the reader, and drag the files onto your hard disk. Access them from there using PS.

Since PS8 would be my primary program to fiddle with the shots taken, it only makes sense to narrow down my choices to cameras that PS8 already supports. That would be my 1st triage in cutting down the available cameras. That should be able to narrow the field to maybe 50 cameras ?

No, it doesn’t narrow down the field at all.

I just haven’t dug into PS8 enough to know anything about it and digital photos or digital cameras.

ie: Canon Mavica a camera I researched yesterday. It uses a 3 1/2 floppy vs digital memory or film. Fine till I saw the $600+ price tag.

Inadvisable.

But what I’m looking for I guess is info on cameras that PS8 doesn’t reject. Or even if the camera has any bearing at all on PS8 ?

Unless you’re shooting RAW files (and I can’t think of a type that ACR doesn’t support except a few of the very newest – i.e. out in the last month or so) it makes absolutely no difference.

—

Hecate – The Real One

veni, vidi, reliqui

On Fri, 19 Nov 2004 00:12:01 +0000, Hecate wrote:

But what I’m looking for I guess is info on cameras that PS8 doesn’t reject. Or

even if the camera has any bearing at all on PS8 ?

Unless you’re shooting RAW files (and I can’t think of a type that ACR doesn’t support except a few of the very newest – i.e. out in the last month or so) it makes absolutely no difference.

So back to the camera ng’s and keep shopping.
tnx
—
more pix @ http://members.toast.net/cbminfo/index.html

I stumbled on a program called DxO (from, surprise: DxO labs). The program reads the EXIF data and corrects chromatic aberrations of specific camera/ lens combinations. You buy the program and the module for your camera and it will largly eliminate curvature, vignetting, chromatic aberrations, etc.

It has done great things for my Minolta A-2, but I don’t know if it as successful with other cameras.

Philip

On Thu, 18 Nov 2004 17:11:26 +0100, (Johan W.
Elzenga) wrote:

Hecate wrote:

Purple fringing is not caused by jpg compression. It is usually caused by poor camera optics.

Wrong. On digital cameras it’s caused by small CCDs.

Actually, it can be both. Small sensors can be a cause, but colour fringing can also be caused by the optics. Even using big sensors like the Canon 1Ds ‘full frame’ sensor you can see color fringing in the corners when a wide angle lens is used. In fact, the *big* size of the sensor is partly the problem, because light hitting the sensor under a steep angle it the main cause. The bigger the sensor, the steeper the angle. That’s why you only see the effect in the corners of the image, not in the centre.

Yes, true. But it’s still the sensor of course. And I take your point about the quality of digital camera lenses – it was just that poster seemed to think that it was only caused by lenses whereas it’s mostly caused by being digital ;’-)

It’s a bit of a chicken and egg, really. I think the best way to discribe it would be "inadequate optics". A small sensor as such does not cause color fringing. But the smaller the sensor, the more it demands from the optics, so even good lenses can become inadequate for a particular sensor. So it’s not the sensor or the lens, it’s the combination that doesn’t match.

Philip Procter wrote:

I stumbled on a program called DxO (from, surprise: DxO labs). The program reads the EXIF data and corrects chromatic aberrations of specific camera/ lens combinations. You buy the program and the module for your camera and it will largly eliminate curvature, vignetting, chromatic aberrations, etc.

It has done great things for my Minolta A-2, but I don’t know if it as successful with other cameras.

Photoshop CS CameraRAW can do this also, if you use it in ‘Expert’ mode.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/