Do I need a CWB when using strobes? (40D)

[flute4peace]

I've just recently been using a 40D at times (started with an XTi), and I've noticed that I'm getting a wide variation in skin tones when I use my strobes (with AWB). It's most noticeable with newborns on a black background - the skin tones vary from blue to red. The first time I thought it was because I had it set on spot metering, but this last time had it set on partial metering and still had a problem. I didn't ever have this problem with the XTi, I'm assuming because the 40 is just a more advanced camera. So...my two questions are:

1. Do I need to set a CWB when using strobes?

and if so,

2. How the heck do I do that?? Meaning, if my focus point placement is affecting the white balance/skin tone fluctuation, how is setting the CWB going to combat that?

Sorry if this is a stupid question, but thank you for your insight/advice.:oops:

[ueb0258]

I always CWB when in the studio. You could use a grey card to do it. I use a photovision calibration target and love it.

http://www.photovisionvideo.com/store/shop.mvc?Screen=CTGY&Category_Code=DCT

[PhotosGuy]

and I've noticed that I'm getting a wide variation in skin tones when I use my strobes (with AWB). 1st, I don't use AWB. Notice that the very last exposure in the 2nd group of tests was of a gray card.
http://photography-on-the.net/forum/showthread.php?t=54281

2nd, maybe you used a longer shutter speed & wider aperture in some shots & the ambient light affected your image? Do I need to set a CWB when using strobes? You're having problems & can't spare 15 seconds to set it? 2. How the heck do I do that?? Meaning, if my focus point placement is affecting the white balance/skin tone fluctuation, how is setting the CWB going to combat that? Focus point placement shouldn't affect the WB. If you shoot the wb image with everything out of focus, you should get the same results.
white balance (http://www.webphotoschool.com/__search/search.php?zoom_query=white+balance&zoom_and=0&zoom_sort=0)

[Curtis N]

A shot of a good white balance reference like a WhiBal card at the beginning of each session will save you a lot of frustration.

If you're shooting JPEG, you'll need to use that shot to set a custom white balance before you shoot. If you're shooting RAW, you can use the reference shot to correct all the images in post with a few clicks.

[flute4peace]

2nd, maybe you used a longer shutter speed & wider aperture in some shots & the ambient light affected your image? I don't think so, I was set at 1/100 and f9.

You're having problems & can't spare 15 seconds to set it? I'm not unwilling, I just never have used it before and was unsure if this was the problem or not.

Focus point placement shouldn't affect the WB. If you shoot the wb image with everything out of focus, you should get the same results. Ok, I was assuming that the information the camera used to "set" the AWB was obtained through the focus point the same way the exposure information is.


Thank you all for your responses. You've confirmed my suspicions and I will now be using a CWB. I had been under the mistaken impression that since it was strobes the CWB was not necessary.

Thank you again!:)

[PhotosGuy]

I'm not unwilling, I just never have used it before and was unsure if this was the problem or not. It's possible, but not highly probable, that your two strobes aren't matched as to WB. You really should do a test, and next time, post an image with the EXIF included so we can see what you're having a problem with.

[zagiace]

It's most noticeable with newborns on a black background - the skin tones vary from blue to red.
That does not sound like a WB issue. Can you post a sample image? I think you have an over exposed image. It could be the relative size of your source light or the balance between your main and fill.