Are my strobes causing WB issues?

[carpenter]

Below are two photos taken 4 seconds apart. I seem to have this issue with W/B a fair amount using the strobes. I am not sure what to attribute it to. This time when I would zoom in I'd get the redder warmer color. When I would zoom out I would get the blue tint. (last time it happened it was reverse) This does not happen each time, but I have noticed it in my studio a couple times and then on location in the barn with these shots. In the barn here I don't really see anything that could have reflected light throwing off the W/B
Strobes are interfit Stellar XD digital backs, Camera is 40D shot with 17-55. I also have had this issue with the 85 1.8. Any help or ideas for me to isolate this issue. I appreciate any help.

http://i267.photobucket.com/albums/ii291/carpenter75/wbissue.jpg

[FlashZebra]

Do you possibly have your camera set to auto white balance?

Enjoy! Lon

[Photon Phil]

Yep looks like auto WB to me.

[carpenter]

Do you possibly have your camera set to auto white balance?

Enjoy! Lon


They were shot in Auto WB yes.

Is AWB that wishy washy in what it sees though? Is that because of the strobes? I guess I should start setting a custom WB.

[Photon Phil]

Yep. Start by just setting if for "flash" and then you'll have at least all the same amount to correct on each. Or do a search for WHiBal. It's a neat tool.

[carpenter]

Yep. Start by just setting if for "flash" and then you'll have at least all the same amount to correct on each. Or do a search for WHiBal. It's a neat tool.

thanks.. just seems wonky that such a slight difference would throw the WB off that far. I'll start with setting it to flash and then as you said.. I can batch change if need be.

[FlashZebra]

They were shot in Auto WB yes.

Is AWB that wishy washy in what it sees though? Is that because of the strobes? I guess I should start setting a custom WB.
Just use either the flash or daylight settings.

Being off reasonably consistently is far better that being off from shot to shot.

Enjoy! Lon

[Photon Phil]

FYI: Be aware that technically flash heads will vary their light color by power setting. So you mat see a little variance even using a preset internal setting such as flash. Until you get you flash power nail down and settings stop varying.

[Curtis N]

This time when I would zoom in I'd get the redder warmer color. When I would zoom out I would get the blue tint.
Is AWB that wishy washy in what it sees though? AWB is the camera's "best guess". Zoom in or out, and you change the amount of background in the shot, changing what the camera has to guess with.

I second the recommendation of the WhiBal card. Shoot RAW, adjust your lights, shoot the card, then it's a few clicks to correct the whole set in post.