01-26-2019 11:38 PM
Hello - I am new here and thanks for having me.
I am having problems getting good focus with my 5D Mk II and I have just noticed that there are green outlines on left of objects and red on right edges. This occurs where there are strong contrasts especially between dark and light colours.
I am using a 24-105 mm 1:4 L IS USM lens.
What could be the problem please?
01-27-2019 06:25 AM
That sounds like chromatic aberration. It is unusual to see in an “L” lens, though.
Notice the purple and green fringing.
The shot was highly cropped. Most lens correction algorithms can remove just about all of it.
01-27-2019 12:04 PM
It is likely CA (chromatic aberration). All lenses have it some just more than others. Mostly it is very easy to correct in post editing. If you don't have a good editor like Photoshop and/or Lightroom, the free from Canon DPP will do the trick.
"I am using a 24-105 mm 1:4 L IS USM lens." Has this lens been damaged in any way? Maybe just a little drop or something?
CA will be more apparent if you enlarge the shot a lot. HIgh contrast areas like white on dark will show it more. If you are using LR you can set up a preset to do CA correction and lens distortion correction upon import. So you will never notice it again.
01-27-2019 05:30 PM
"I am using Photosop CS6."
Shoot Raw file format and use ACR to convert the file into PS. CA is easily corrected in ACR. Also do lens correction in ACR.
01-27-2019 05:33 PM
"(Which was all I could afford at this time)"
The 5D Mk II and ef 24-105mm f4L is a very nice combo. It made me a lot of money for along time.
01-27-2019 05:37 PM
Hello. I bought both the camera and lens second-hand.
(Which was all I could afford at this time)
The 24-105mm f/4l is a pretty good lens and shouldn't be exhibiting noticeable chromatic aberration. If you can't correct it in post-processing, you might want to have Canon look at it and see if something is out of alignment. Is there any evidence that the lens has been dropped?
01-28-2019 04:39 AM
I always shoot in RAW and if I remember correcrtly there was no (or barely perceptible) red/green outlines in PS RAW editor.
However, once the image opens from RAW to PS, then zoomed to 100% the lines are there.
I took this image as I was having trouble getting a focussed image (f11/100). The green and red lines are clear on the metal work against the white concrete tank stand. This is a jpeg for web, but the tiff has the lines too.
I'll look into doing what you advised.
I used a borrowed camera all last semester from uni (same Canon model and lens) yet no aberrations.
Thanks for your advice.