alright so let me get this straight, you basically put the gray card in your light box (im using a lightbox), take a picture of the gray card and use that picture to set the white balance?
alright so let me get this straight, you basically put the gray card in your light box (im using a lightbox), take a picture of the gray card and use that picture to set the white balance?
In your case, you would put the gray card in your lightbox. But no matter where you are and what you are shooting, the idea is to place the gray card in the same light as your subject. That will allow you to one-click-set-your-white-balance in post. But that only works until the light changes on your subject (theatrical lighting is altered, the sun is obscured by a passing cloud, etc.)