Ugly green shadows on 50D images

[ggoldthorpe]

Hiya all - I am hoping that I can elicit some insight into what I am sure is a new phenomenon on my images. I had planned to attach an example but I'm having serious internet issues at the moment and can not upload. I'm hoping that what I describe below will be familiar enough to someone that you can comment without visuals.

I have started noticing some green coloring within the shadows of some of my images. It tends to happen on light coloured subjects such as caucasian skin on people or white plumage on birds and is sometimes so distinctive that it can be noticed without zooming in.

I have no idea what causes this or even where the root of the problem is (i.e. camera, raw converter or monitor) so I have no idea where to start with solving the problem.

I am using a Canon 50D with a EF100-400mm f4.5-5.6L lens (the lens was recently serviced) with a MacBook using the Digital Photo Professional raw converter software that came with the camera. I have used the Macs built-in calibration tool but have never used an external monitor calibration kit on it.

Does anyone have any ideas what is causing this and, most importantly, what I need to do to get rid of it?

Cheers - Gareth

[RichardTaylor]

(1) Are they back lit subjects, and the fringes in high contrast areas?
(2) Are you using a filter on the front of the lens?
(3) Does it happen with other lenses.
(4) Are you using a lens hoood?

[BigFuzzy]

Do they appear green on your screen while still in camera (ie the LCD on the back)? Or only after you upload them?

Have you tried printing one and seeing if that color tint is there?

Is it happening with all images or just one particular recent shoot?

Yeah, an attachment (with exif) would really help.

[kcoppock]

Also, does it appear in Photoshop that way, or only after you export them (JPG, etc)? If it's only after you export, it's likely that you're using a different color profile, and the short answer would be that you can just convert them to sRGB to mitigate this problem.

[faeriegodess612]

Just to throw this out there,.... sometimes we get so caught up in other things, that we forget some tiny detail,....but your WB isnt set on Flourescent is it? Like maybe outside against a blue (sky) or green ( trees and shrubbery) background you wouldnt notice it that much, but against something white it shows?

[ggoldthorpe]

Hi Richard - to answer your questions:
(1) Are they back lit subjects, and the fringes in high contrast areas? No
(2) Are you using a filter on the front of the lens? Only a DHG lens protector
(3) Does it happen with other lenses? Not that I've noticed. The only other lens that I use to any real degree is a 28mm so the images from that aren't really the type to feature a lot of shadow areas.
(4) Are you using a lens hoood? Yes

Do any of these provide an answer? The lens protector might be a suspect I guess (I used to have a cheap UV filter on the lens and that was seriously affecting the sharpness of the lens but this protector is supposed to be good quality.

Still working on uploading some examples,

Gareth

[ggoldthorpe]

And your questions:

Do they appear green on your screen while still in camera (ie the LCD on the back)? Or only after you upload them? I can't say I've looked but considering how obvious it is with the uploads I'm guessing not.

Have you tried printing one and seeing if that color tint is there? No but I will.

Is it happening with all images or just one particular recent shoot? I've started to notice it recently but over several different occasions; but not on all the images within an occasion (I've checked the exif on a selection to see if it is something obvious like ISO but to no avail).

Yeah, an attachment (with exif) would really help. Working on it.

[ggoldthorpe]

Also, does it appear in Photoshop that way, or only after you export them (JPG, etc)? If it's only after you export, it's likely that you're using a different color profile, and the short answer would be that you can just convert them to sRGB to mitigate this problem.

It first seems to appear (see response to above) in the raw converter (Digital Photo Professional) and on all subsequent (jpeg) exports.

Could it be that I have the wrong colour profile (sRGB) selected in the camera? I use a MacBook for uploading and I have, in the past, played around with the colour profile for the screen - maybe the problem lies there.

Cheers,


G

[ggoldthorpe]

Originally Posted by faeriegodess612

Just to throw this out there,.... sometimes we get so caught up in other things, that we forget some tiny detail,....but your WB isnt set on Flourescent is it? Like maybe outside against a blue (sky) or green ( trees and shrubbery) background you wouldnt notice it that much, but against something white it shows?

Thanks for throwing but i don't think that's it. I shoot RAW so I generally keep the WB setting to auto and change accordingly in processing.

Cheers,

G

[RichardTaylor]

See how it goes without the lens protector.