why would I get a color cast when I zoom in.

[carpenter]

I did a shoot today for a friend indoors with strobes. If I was zoomed further out (17mm)I had correct colors. The more I would zoom in tight the more of a color cast and incorrect WB I would get. Examples in the following. the more I am zoom in the grayer and paler faces look. Just curious what causes this.

580EX II camera right. strobe camera left and lighting BG.

40D AWB, 17-55 lens

http://cryo-laboratory.com/uploader/files/6/cast1.jpg

http://cryo-laboratory.com/uploader/files/6/cast2.jpg

[bsaber]

Did you have the camera on auto WB? If so that would just be the camera misjudging.

[carpenter]

Did you have the camera on auto WB? If so that would just be the camera misjudging.


yes, it was on AWB. that is my next step I suppose.. getting it off of AWB.

[SkipD]

yes, it was on AWB. that is my next step I suppose.. getting it off of AWB.In my opinion, you should forget that AWB ever existed. I've found AWB in my 20D to be wrong far more often than correct.

You should obtain a neutral target for either setting "custom white balance" or placing in a test shot (for tweaking white balance in post processing).

Shooting in RAW mode (or RAW plus JPG like I do) allows you the simple option of tweaking white balance after the fact.

[cdifoto]

AWB is demon spawn.

[bsaber]

In a controlled environment setting it's best to use a custom WB.

[carpenter]

thanks, I will be getting off AWB by my next shoot. Any somewhat quick "fix" for the shots that are in Jpeg? I will also go back to shooting RAW for studio shots.

[cdifoto]

thanks, I will be getting off AWB by my next shoot. Any somewhat quick "fix" for the shots that are in Jpeg? I will also go back to shooting RAW for studio shots.
No quick fix that does a good job that I know of, but you don't have to go back to RAW in the studio if you're gonna set a custom white balance. At least not for that particular benefit.

[polarbare]

you can open jpgs in the new versions of camera raw in photoshop and fix those color casts in 10 seconds.

[cdifoto]

you can open jpgs in the new versions of camera raw in photoshop and fix those color casts in 10 seconds.
Might take a little longer than that since you can't batch variations. If they're all off by the same amount then yeah. Otherwise, individual tweaking is needed.

[Persephone]

In my opinion, you should forget that AWB ever existed. I've found AWB in my 20D to be wrong far more often than correct.

You should obtain a neutral target for either setting "custom white balance" or placing in a test shot (for tweaking white balance in post processing).

Shooting in RAW mode (or RAW plus JPG like I do) allows you the simple option of tweaking white balance after the fact.

I've found that the later models have better AWB. I once put my 20D and my SX110 on a tripod and shot the same sky. 20D AWB couldn't replicate it right, while the SX110 looked good.

After learning about custom WB, I've tried a lot to steer away from AWB and use tungsten and florescent instead, but sometimes, I've tried AWB and for some reason like that color cast in a few cases. Sometimes I prefer it over florescent.

[carpenter]

you can open jpgs in the new versions of camera raw in photoshop and fix those color casts in 10 seconds.

didn't even think about that.. worked VERY well. Thank you.