Red edges to Sparkles from EOS 20D

[POP]

Hello All    

I have an EOS 20D, and on the whole am very happy with it, unless I am trying to take pictures facing the sun where the sun is reflected off of water, where I am getting red around sparkles!

Using the Canon viewing software the redness is visible in the thumbnails, when you view the image in the viewer utility before it has fully loaded the image and you get to see a very low res image the redness is there until the full res image loads and the redness is gone (and that is the only way I can see these images without redness!).

In all Adobe software (Bridge/CS2) the redness exists, and the redness prints aswell  

Examples:

Peter

[Tim Gray]

do a search for "Purple fringing" - or chromatic abberation, there's a dialog in ACR or Lightroom under Lens Correction that let's you minimize the effect.  Not sure how effective Lightroom would be against a JPG (you could try) and obviously the ACR dialog is only available for RAW.

[POP]

do a search for "Purple fringing" - or chromatic abberation, there's a dialog in ACR or Lightroom under Lens Correction that let's you minimize the effect.  Not sure how effective Lightroom would be against a JPG (you could try) and obviously the ACR dialog is only available for RAW.
[a href=\"index.php?act=findpost&pid=106252\"][{POST_SNAPBACK}][/a]

I have tried the Chromatic Aberation adjustment in ACR, it helps but this clearly is not a case of CA, and is not fixable with ACR unfortunately.  The JPG images supplied have nothing to do with the purple fringing, I can provide a DNG image or a CR2 image or a PSD image that look just like the JPG images.

People have talked about wide/ultrawide angle lenses being responsible for CA but the images supplied are at 40mm (64mm) and it occures with my tele zoom lens aswell    

Admittedly I have not read all the posts I found (tired and ready to go to bed) but I read people stating that the purple fringing is not an issue with the 20D, and yet I strongly beg to differ, so I am wondering is it a fault with my particular camera, though I doubt it frankly.  Are there any 20D owners out there that recognise my purple fringing?

I read (for example) Jonathan Weinke's method of curing it and will try that I guess, though I was hoping for some magic way of making it not show up in the first place really hehe, none the less thanks for the reply Tim  

Peter

[francois]

I have tried the Chromatic Aberation adjustment in ACR, it helps but this clearly is not a case of CA, and is not fixable with ACR unfortunately.  The JPG images supplied have nothing to do with the purple fringing, I can provide a DNG image or a CR2 image or a PSD image that look just like the JPG images.

People have talked about wide/ultrawide angle lenses being responsible for CA but the images supplied are at 40mm (64mm) and it occures with my tele zoom lens aswell   

Admittedly I have not read all the posts I found (tired and ready to go to bed) but I read people stating that the purple fringing is not an issue with the 20D, and yet I strongly beg to differ, so I am wondering is it a fault with my particular camera, though I doubt it frankly.  Are there any 20D owners out there that recognise my purple fringing?

I read (for example) Jonathan Weinke's method of curing it and will try that I guess, though I was hoping for some magic way of making it not show up in the first place really hehe, none the less thanks for the reply Tim 

Peter
[a href=\"index.php?act=findpost&pid=106262\"][{POST_SNAPBACK}][/a]

Try a different RAW converter. Your purple fringing might be somewhat reduced. Other than that, you'll need to lessen PF in Photoshop. Also, have you tried to remove your front UV filter? I've rarely seen such severe PF, even when I shoot near water.

[Tim Gray]

So you've peaked my curiosity - can you post a link to a DNG?

[dlashier]

Demosaicing artifacts due to channel clipping. As already mentioned, some raw converters will handle this much better than others. C1 is worth a try if you haven't tried already.

- DL

[POP]

So you've peaked my curiosity - can you post a link to a DNG?
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Oki Doki, I'm not sure about how to do this but I will give it a try  

the same as the example one:
[a href=\"http://www.pictures-of-paradise.com/images/115526_Sunlight_reflected_from_the_sea_-_Paekak_hilltop_(40mm).dng]115526_Sunlight_reflected_from_the_sea_-_Paekak_hilltop_(40mm).dng[/url]

and similar one but from EF 70-200mm F4L @ 70mm:
115527_Sunlight_reflected_from_the_sea_(with_2_boats)_-_Paekak_hilltop_(70mm).dng

If the links work I will leave them there for awhile but will delete them eventually since they take up alot of space...

Seems they do work when I previewed them so have a look and let me know what you think, my curiosity was tweaked awhile back    

Peter

[POP]

Demosaicing artifacts due to channel clipping. As already mentioned, some raw converters will handle this much better than others. C1 is worth a try if you haven't tried already.

- DL
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Pardon my lack of knowledge in the achronyms DL, and good to have your feed back, but what is 'C1' (I understand it is a RAW converter, but is it a plug in for PShop or stand alone, or...)? and where do I get it?  and does it cost an arm 'n a leg?

Peter
P.S. POP stands for [a href=\"http://www.pictures-of-paradise.com]pictures of paradise[/url] (shamless plug for my site)

[DarkPenguin]

Capture One.  Go to Phase One to try a demo.  Probably www.phaseone.com

[BernardLanguillier]

I have found Raw Developper to be good at getting rid of similar issues.

RD is unfortunately only available for Mac at this stage.

Cheers,
Bernard

[dlashier]

Peter, if you want to send me the raw file I'll give it a try in C1 and post the result. There's an upload file link on my "about" page.

- DL

[POP]

Hi all again, it has been a busy day  

I went to PhaseOne and downloaded a 15 day trial of CaptureOneLE and eventually got a chance to give it a try...

Surfice it to say that Adobe Camera Raw and CaptureOne are quite different to each other, since I have used ACR all my digital life, I have come to feel right at home with it, and found C1 clumsy and imprecise to use, but I guess with time it would get better (perhaps).  However the crux of the matter!

With C1:
 

Digital processing is just incredibly complex, though saying that, I guess it is not that different, but it's just that all the adjustments are in my hands now and I am coming upon a steep learning curve. I was ready to fork out US$99 for C1 but now I'm not so sure again  

Perhaps Dlashier I could take you up on your kind offer and upload a DNG file to you and see what you make of it? It would be great to remove all my uncertain methods and have someone who really knows what they are doing can reveal    If you left a mail at my site with a password for the file upload section perhaps?

Cheery
Peter
Pictures of Paradise

[Ben Rubinstein]

Looks like blooming to me. That is (I think) where the pixels next to blown out pixels get some sort of light leak from the blown out areas which appears red/purple. I've not found a good way to get rid of the problem but it often occurs with edges where one side is blown out and the other is not, you will see it often in sunsets for example.

[POP]

Looks like blooming to me. That is (I think) where the pixels next to blown out pixels get some sort of light leak from the blown out areas which appears red/purple. I've not found a good way to get rid of the problem but it often occurs with edges where one side is blown out and the other is not, you will see it often in sunsets for example.
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Maybe the individual pixels of the sensor needs little tiny lens hoods...  Or possibly larger sites on a larger sensor, but then you would be buying a 5D   It is ashame that Adobe seem to have fallen short on incorporating the phenomenon into their algorythums quite as well as apparently some other software makers have.

Bed time here in New Zealand (way past it actually) so good night  

Peter
[a href=\"http://www.pictures-of-paradise.com]Pictures of Paradise[/url]

[dlashier]

Peter, I forgot that upload requires a password. I'll have to look it up later but I'm pretty certain that it's "upload".

- DL

[Tim Gray]

Probably the result of the nasty clipping.  It can be fixed at the cost of some major desaturation (my first play with the targetted saturation tool in Lightroom), but the chromatic aberation tools in LR didn't do much.

[attachment=2089:attachment]

[dlashier]

Probably the result of the nasty clipping.
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Yup Tim, I agree.

and btw Peter, the pw is "upload" as I thought. Nothing secret here, just trying to keep out the teenies who stumble on the site.

- DL

[John Sheehy]

I have an EOS 20D, and on the whole am very happy with it, unless I am trying to take pictures facing the sun where the sun is reflected off of water, where I am getting red around sparkles![a href=\"index.php?act=findpost&pid=106239\"][{POST_SNAPBACK}][/a]

That's infrared light, in too strong a dose for the hot-cut filter to cut it out.  What is happening is that the curves in the water are making parabolic mirrors that increase the intensity of light in certain spots, and your lens is not focusing the IR as well as the visible, so you get strong IR right outside the blown-out areas.

[John Sheehy]

Admittedly I have not read all the posts I found (tired and ready to go to bed) but I read people stating that the purple fringing is not an issue with the 20D, and yet I strongly beg to differ,[a href=\"index.php?act=findpost&pid=106262\"][{POST_SNAPBACK}][/a]

There are three distinct phenomena that people call "purple fringing".  In your case, it is infrared light that is out of focus, and doesn't blow out with the visible light.  Different lenses focus IR differently.

Some people call CA "purple fringing" which is a really bad idea, IMO.

The other thing is that CCD sensors can "bloom"; pixels can saturate and overflow charge into their neighbors.  This overflow is generally from green into red and blue pixels, and the daylight WB calls for boosting red and blue anyway, so the leakage converts as a purple or magenta color.

[POP]

Don, I tried the upload link but I got a page that said there was a problem    try right clicking this link and downloading it to your HDD:
115526_Sunlight_reflected_from_the_sea_-_Paekak_hilltop_(40mm).dng
(I dont normally have understrokes in my file names but for the purposes of transfer I have included them)

John, it is great to read your break down of the problem and it rings true for the example included.  I guess when you have pin point lights in a night time scene it would be the CCD sensor bloom?  I do whole heartedly agree that calling CA 'purple fringing' is highly misleading and tends to make it hard for people that are trying to discuss one thing not to have it confused with another thing (however similar they may be infact).

Cheery
Peter
Pictures of Paradise