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

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.

1715 x 591

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What's the shutter speed on these? I think you're catching the cycling of the lights.

jm_usmc wrote in post #12349531
What's the shutter speed on these? I think you're catching the cycling of the lights.

Shutter speed varied from 1/100 to around 1/1250 depending on the aperture and ISO used

Slowing your shutter speed will help. It's normal with faster shutter speeds and fluorescent lighting to get odd colors. It's not your lens or camera - it's the nature of cyclical lighting.

oldvultureface wrote in post #12349565
Slowing your shutter speed will help. It's normal with faster shutter speeds and fluorescent lighting to get odd colors. It's not your lens or camera - it's the nature of cyclical lighting.

On these two, the left one was taken at 1/320, the right one at 1/400:

Slower, cycling of fluorescent lights.

I'm pretty sure you'll have to be less than 1/60th to prevent this.

jm_usmc wrote in post #12349531
What's the shutter speed on these? I think you're catching the cycling of the lights.

definitely the refresh rate on the flour-lites 60hz and every variation of it...as noted by jm. No problem with the equipment. do a little search on "Limitations of Flourescent Lighting" here on POTN... details are there

https://photography-on-the.net ….php?p=790596&p​ostcount=1

flourecent indeed. I just cheat by setting it to auto ISO and Tv and do 1/60 if i'm feeling super lazy, other wise I try and just do it right