John Mitchell Posted August 10, 2015 Share Posted August 10, 2015 I would appreciate some help with the image below. Is this (100% crop) CA or some kind of colour fringing/bleeding? The photo was taken just before sunset, so there was lots of red light around. It certainly looks a lot like CA, but CA sliders have absolutely no effect on the RAW version. Chances are I won't submit this image to Alamy (too risky), but I would like to know. Thanks in advance. Link to comment Share on other sites More sharing options...
Armstrong Posted August 10, 2015 Share Posted August 10, 2015 Link not working for me! Link to comment Share on other sites More sharing options...
John Mitchell Posted August 10, 2015 Author Share Posted August 10, 2015 Link not working for me! fixed, see below Link to comment Share on other sites More sharing options...
Lastrega Posted August 10, 2015 Share Posted August 10, 2015 Link still not working..................... Link to comment Share on other sites More sharing options...
John Mitchell Posted August 10, 2015 Author Share Posted August 10, 2015 Link still not working..................... Bummer. How about now? Link to comment Share on other sites More sharing options...
Craig Yates Posted August 10, 2015 Share Posted August 10, 2015 Nope. Regards Craig Link to comment Share on other sites More sharing options...
John Mitchell Posted August 10, 2015 Author Share Posted August 10, 2015 It looks as if PhotoShelter links aren't working here (except for me). Will have to try another option. Sorry. Link to comment Share on other sites More sharing options...
John Mitchell Posted August 10, 2015 Author Share Posted August 10, 2015 Here it is. At last. I hope. Link to comment Share on other sites More sharing options...
Armstrong Posted August 10, 2015 Share Posted August 10, 2015 That's worked! Link to comment Share on other sites More sharing options...
Armstrong Posted August 10, 2015 Share Posted August 10, 2015 Sorry to be a pain...just so I get the context, it's the red around the side of the orange? Is it a metal beam with an orange safety type surface? Link to comment Share on other sites More sharing options...
John Mitchell Posted August 10, 2015 Author Share Posted August 10, 2015 Sorry to be a pain...just so I get the context, it's the red around the side of the orange? Is it a metal beam with an orange safety type surface? Yes, it's the red fringe around the sides of the orange metal support beam. Don't know if it's the type of surface that you mentioned. CA sliders have no effect. P.S. If you click on the image, there is a "save" option. Link to comment Share on other sites More sharing options...
spacecadet Posted August 10, 2015 Share Posted August 10, 2015 Even with my criminal record, some of it for CA, I'd say no, it's colour flare. I'm paranoid about it as well. Link to comment Share on other sites More sharing options...
John Mitchell Posted August 10, 2015 Author Share Posted August 10, 2015 Even with my criminal record, some of it for CA, I'd say no, it's colour flare. I'm paranoid about it as well. Thanks for the opinion. That's what I think as well. I haven't had the pleasure of a sin bin sojourn for a long time, and my shrink is probably on summer vacation. Hence the extreme paranoia. Link to comment Share on other sites More sharing options...
Jill Morgan Posted August 10, 2015 Share Posted August 10, 2015 Try the Defringe slider in ACR. Has saved many of my images. Jill Link to comment Share on other sites More sharing options...
Johnnie5 Posted August 10, 2015 Share Posted August 10, 2015 I just found a neat trick in Lightroom. Using the color sliders in the HSL panel pick the color red and move the Hue slider to the right. It seems to change the red to match the orange which then makes the red disappear. I have no idea what it will do to the rest of the photo but its worth a try. You can also de-saturate the red and dial down the luminance which may have a negative affect on the whole photo but is worth a try. Link to comment Share on other sites More sharing options...
Armstrong Posted August 10, 2015 Share Posted August 10, 2015 Sorry to be a pain...just so I get the context, it's the red around the side of the orange? Is it a metal beam with an orange safety type surface? Yes, it's the red fringe around the sides of the orange metal support beam. Don't know if it's the type of surface that you mentioned. CA sliders have no effect. P.S. If you click on the image, there is a "save" option. I don't think it's CA but as it stands I wouldn't submit. I don't think it looks horrendous but I'd err on the side of caution. Some of the suggestions above sound good. Link to comment Share on other sites More sharing options...
John Mitchell Posted August 10, 2015 Author Share Posted August 10, 2015 Thanks for the helpful suggestions. I'm using DxO OpticsPro to process my RAW images. The fringing (purple only in DxO) slider has no effect. However, there is an HSL panel. I'll play around with it. I can always go back and re-shoot this image at another time of day. I've seen this effect before with red subjects shot at sunset with this same lens. Didn't submit those images either. Link to comment Share on other sites More sharing options...
Bill Brooks Posted August 12, 2015 Share Posted August 12, 2015 Is this the main subject of the image or is it from an unimportant corner? Do the important parts of the image show the same fringing? If it is not an important part of the image, and the important part of the image does not show the same fringing, I would submit the image as is. When you have such an abrupt change of colour/luminance and slight softness, a slightly soft edge will bleed over into the dark part. If the dark part was lighter, or any colour, the slight bleed would still be there, but not show. I have seen this edge in photoshop when dropping a bright red maple leaf onto a blue/green sky background. Grey edge due to mingling of 3 colours for one or 2 pixels. This effect could be caused by soft corners due to lens curvature of field, lens flare, secondary image caused by a filter on the lens, Zoom lens, cheap lens, internal flare in camera. Link to comment Share on other sites More sharing options...
John Mitchell Posted August 12, 2015 Author Share Posted August 12, 2015 Is this the main subject of the image or is it from an unimportant corner? Do the important parts of the image show the same fringing? If it is not an important part of the image, and the important part of the image does not show the same fringing, I would submit the image as is. When you have such an abrupt change of colour/luminance and slight softness, a slightly soft edge will bleed over into the dark part. If the dark part was lighter, or any colour, the slight bleed would still be there, but not show. I have seen this edge in photoshop when dropping a bright red maple leaf onto a blue/green sky background. Grey edge due to mingling of 3 colours for one or 2 pixels. This effect could be caused by soft corners due to lens curvature of field, lens flare, secondary image caused by a filter on the lens, Zoom lens, cheap lens, internal flare in camera. Thanks, Bill. The crop is from an unimportant part of the image. The main subject does not show the colour bleeding, or whatever it is. However, in my experience, Alamy QC does not see one part of an image as being more important than another (except where main focus point is concerned). There is no mention of this type of thing in Alamy's submission guidelines, but my fear is that the QC inspector will think the red stuff is -- or looks like -- chromatic aberration. Possibly spending a month waiting to find out doesn't appeal, although my QC record may be good enough these days to avoid incarceration. Still, one never knows... Link to comment Share on other sites More sharing options...
spacecadet Posted August 12, 2015 Share Posted August 12, 2015 CA at the extreme edges of an image has done for me a couple of times. I click the LR button for every image with sky in it. I don't even look for the CA anymore. Another option would be a moderate burn-in of the area. Link to comment Share on other sites More sharing options...
John Mitchell Posted August 12, 2015 Author Share Posted August 12, 2015 CA at the extreme edges of an image has done for me a couple of times. I click the LR button for every image with sky in it. I don't even look for the CA anymore. Another option would be a moderate burn-in of the area. Luckily, I've never had a fail for CA. Don't think I'll bother spending any more time on this image. I'll try retaking it when the sun is higher in the sky and from a different angle. Thanks again, everyone, for all the help. Link to comment Share on other sites More sharing options...
Bill Brooks Posted August 17, 2015 Share Posted August 17, 2015 I would appreciate some help with the image below. Is this (100% crop) CA or some kind of colour fringing/bleeding? The photo was taken just before sunset, so there was lots of red light around. It certainly looks a lot like CA, but CA sliders have absolutely no effect on the RAW version. Chances are I won't submit this image to Alamy (too risky), but I would like to know. Thanks in advance. It is not a lens issue it is a sensor issue. In his book “Adobe Photoshop for Photographers CS5” Martin Evening talks about intense colour or very bright luminance bleeding onto adjacent pixels on the sensor chip. It presents itself in the dark areas when there is a abrupt change in colour or luminance from very bright to very dark. It is everywhere, under these conditions, but we usually do not notice the bleed because of the background. A pixel senses intense, over the top, brightness and then electrically stimulates it’s neighbor pixel. This stimulus overflow causes the neighbor pixel to detect a small amount of brightness, when in fact it should detect nothing. So it is not chromatic aberration it is an adjacent pixel stimulus issue on the sensor chip caused by intense color or luminance. CA correction in software therefore will not work. Link to comment Share on other sites More sharing options...
John Mitchell Posted August 17, 2015 Author Share Posted August 17, 2015 I would appreciate some help with the image below. Is this (100% crop) CA or some kind of colour fringing/bleeding? The photo was taken just before sunset, so there was lots of red light around. It certainly looks a lot like CA, but CA sliders have absolutely no effect on the RAW version. Chances are I won't submit this image to Alamy (too risky), but I would like to know. Thanks in advance. It is not a lens issue it is a sensor issue. In his book “Adobe Photoshop for Photographers CS5” Martin Evening talks about intense colour or very bright luminance bleeding onto adjacent pixels on the sensor chip. It presents itself in the dark areas when there is a abrupt change in colour or luminance from very bright to very dark. It is everywhere, under these conditions, but we usually do not notice the bleed because of the background. A pixel senses intense, over the top, brightness and then electrically stimulates it’s neighbor pixel. This stimulus overflow causes the neighbor pixel to detect a small amount of brightness, when in fact it should detect nothing. So it is not chromatic aberration it is an adjacent pixel stimulus issue on the sensor chip caused by intense color or luminance. CA correction in software therefore will not work. So, since it's omnipresent in digital images, do you still think this one might be OK to submit (unfair question, I know)? Link to comment Share on other sites More sharing options...
Bill Brooks Posted August 18, 2015 Share Posted August 18, 2015 You may be able to get rid of this red bleed by setting the black point even darker. I often get rid of noise in the blacks by setting the black point darker until the noise disappears. If a black background has no detail but some noise at a value of 10, I set the black point to level 10. This eliminates all noise that has a value of 10 or below. In your image there is no significant detail in the blacks except the bleed, and you want to get rid of the bleed. In Adobe Camera Raw this black point adjustment will have hardly any effect on the shadows. If it does, raise the shadows slider slightly until the bleed starts to reappear. Make the adjustments and then check out the image overall to see if it still pleases you. Purple fringing on tree branches is the same thing in the whites. I will sometimes raise the white point to eliminate the purple fringing. Link to comment Share on other sites More sharing options...
John Mitchell Posted August 18, 2015 Author Share Posted August 18, 2015 You may be able to get rid of this red bleed by setting the black point even darker. I often get rid of noise in the blacks by setting the black point darker until the noise disappears. If a black background has no detail but some noise at a value of 10, I set the black point to level 10. This eliminates all noise that has a value of 10 or below. In your image there is no significant detail in the blacks except the bleed, and you want to get rid of the bleed. In Adobe Camera Raw this black point adjustment will have hardly any effect on the shadows. If it does, raise the shadows slider slightly until the bleed starts to reappear. Make the adjustments and then check out the image overall to see if it still pleases you. Purple fringing on tree branches is the same thing in the whites. I will sometimes raise the white point to eliminate the purple fringing. Thanks again for the tips. I'll experiment with the black point and see if that makes a difference. Link to comment Share on other sites More sharing options...
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