Need help for manual white balanc

[chikeang]

hi every one ,I just build a studio for photo at home my problem is ,i can not get a correct colore for portrait photo,some dark area on the face become little bit yellow ,even i use a proper white paper for manual white balance set up ,if i go to auto white balance the colore is little better but still not satifaction ,the question is my camera g2 has a problem or the technology of digital camera ccd is limit ? or anything else ?
I use 2 externals flash with slave control and umbrela for reflect back and another flash with remote control plug from my G2 (i use 3 flash) *note in my studio there are no external light penetrate . I set the camera to manual at speed 160/s and 2.2 for aperture
thank you

CHIKEANG
MONTREAL

[SkipD]

It sounds to me like your exposure may be a little bit off. I have noticed with my G2 that by changing the exposure there is sometimes a slight color change.

I would suggest that you check the histogram to see if you are getting a proper exposure. The curves should not extend beyond either end of the scale. If you don't understand what I'm referring to after reading the book, several folks will be willing to help here.

For portraits, you probably want enough light to be able to stop down at least halfway to get suitable depth of field. Moving the lights closer to the subject would help. Moving the umbrellas closer to the subject also has the benefit of making the light softer.

[leony]

Actually, if you're using strobes (flash heads) you don't need to use manual WB. For once, the flash is too fast for you to set the WB manually and what you end up doing is setting WB to the ambient light, not the flash. You might have better luck if you switch to "Flash" White Ballance - it's the second setting from the right in the WB menu. Auto WB is only good for ambient light, not flash. I've used a 2 flash set up (550EXs) triggered by TTL Transmitter (the name escapes me at the moment, but Canon only makes one)and have had great results with WB set to "flash."

Hope this helps.