HELP! Strange color casting issues with 5D + Sigma 50

996GT2

Diamond Member
Jun 23, 2005
5,212
0
76
Never had this happen before, so I'm a little worried.

I noticed earlier tonight (while taking some snapshots at a party) that my 5D and Sigma 50 f/1.4 were producing strange color casts under fluorescent light.

Below is an example of what I'm talking about.

The degree of casting changes depending on the photo but it seems to happen at a variety of shutter speeds and apertures. The casts only affect PART of the picture, so it does not seem like a white balance issue.

I am not using any kind of protective filter, and these pics were taken with a lens hood in place. No flash was used.

I also tried the Sigma 50 on another camera (a 50D), and it produced similar casting. However, a different lens on my 5D seemed to be fine.

Testing it on the 50D and seeing the same casting made me think it was a lens specific issue, but what could cause the lens to cause color casts like these? Also, is there any chance it's an issue with my 5D's shutter assembly? It almost looks like a flash pic where one part of the photo is not synced properly.

5dcasting.jpg


Here is another example. Notice how the bottom half looks different from the top half.
casting2s.jpg


Notice how the color casting is different in each photo:
casting4.jpg
 

xchangx

Golden Member
Mar 23, 2000
1,692
1
71
Yep. Shoot with faster shutter speeds when there are flourescent lights around. You'll get weird colors ranging from green to beige to purple if you don't.

It's actually slower shutter speeds. Since the lights are cycling 60 times per sec any shutter speed faster than 1/60 has a high probablility that you will get it in mid-cycle, which is what is causing the bars.