Weird Vignetting: Sigma 50mm 1.4

Is this normal? I am testing a Sigma 50mm 1.4 for purchase.

When shooting at 1.4 and then viewing the image on the back of my 5d2 i see a black ring around the image like a vignette. In lightroom, prior to importing the ring is there, but it disappears after the import. I thought it was the hood or the filter but after taking both off, the rings are still there.

The images look good after import (without any lens correction) and there is no trace of the ring. I really like the way the images come out but I am trying to figure out if this is normal for this lens or is this a lemon. I want to hear from other sigma 50mm 1.4 owners on FF. Please advise.

Thank you

(Attached are two images screen captured on my mac to show what i am talking about.)

OK, I'm curious. I don't use LR so won't be any help.

If I had to guess, it looks like software identifying something - it's like LR is showing where vignetting is - inner ring 1 stop, outer ring 2 stops under....

Only for this lens? If the problem disappears when you import the files, then there might be a problem with your camera's jpg preview generation.

Well, it doesnt happen with my other lenses. And it is also showing up on the back of my 5d2 preview.

It shows up in remote shooting using the EOS utility when I shoot JPG instead of RAW. It is also most pronounced at ISO 640. Just tried my other lenses, to make sure my camera didn't develop the issue recently and still only shows up with this lens.

do you have peripheral illumination correction (or whatever it is called) turned on on that 5D2?

SMP_Homer wrote in post #15733903
do you have peripheral illumination correction (or whatever it is called) turned on on that 5D2?

http://www.learn.usa.c​anon.com …_peripheral_art​icle.shtml
Peripheral Illumination Correction is automatically applied to JPEG images when the cameras are set to Full Auto or Creative Auto, or to any of the Basic Zone exposure modes

ISO200. Shot Small JPG remotely into Canon EOS Utility

Choderboy wrote in post #15733920
http://www.learn.usa.c​anon.com …_peripheral_art​icle.shtml
Peripheral Illumination Correction is automatically applied to JPEG images when the cameras are set to Full Auto or Creative Auto, or to any of the Basic Zone exposure modes

I am shooting in Manual Also tried AV

losangelino wrote in post #15733944
I am shooting in Manual Also tried AV

Do you have peripheral illumination correction turned on?
on a 5D2, this is in the red menu

I just turned it off. That seems to have fixed it. Should that be a concern?

losangelino wrote in post #15733972
I just turned it off. That seems to have fixed it. Should that be a concern?

No.

http://www.lensrentals​.com …on-and-third-party-lenses

Okay. Thank you. You guys are awesome

losangelino wrote in post #15733972
I just turned it off. That seems to have fixed it. Should that be a concern?

I've seen this with various 3rd party lenses... my Sig85 doesn't do it with any of my bodies, but does on a friend's 5D2... one of 3 diff Sig50 does this on my 5D2, but not any other bodies...