white balance question

[TylerF]

So recently I have seen people taking portraits but before that, they hold up a card. I'm assuming this has something to do with the white balance? If so, what is it and how do u use it? I'm trying to better my portrait taking.

Thanks

 

[keith foster]

Probably a grey card. You are right, it is used to set white balance. Lots of information and discussions on grey cards on here so I won't go into it. Just do a quick search and you will find all you need.

 

[wtdeane]

Hey Tyler,

You are right. What you are seeing is a neutral density card. I use these quite often.

I set-up the model (or scene) and have them hold the card to take a test shot. Then I focus on the whole shoot; never needing to do this step again.

Then, when I am back in PP mode, I use the first shot with the card and use my white point balance based on the values returned form sampling the card. Then, I can apply the new white point setting to all the shots in the series.

Viola. Perfect white balance.

Be careful. Not all neutral density cards are created equally. I use WhiBal cards. You can find more info here:
Digital Photography - RawWorkflow.com - WhiBal Certified Gray Card for White Balance

Sometimes I use an ExpoDisc. You place this special cap over the lens and expose a frame while pointing to the major light source that will hit your subject. In some situations, I like this tool better. You can find info here:
ExpoImaging - ExpoDisc

(No, I am NOT affiliated with these companies. I just really love the products)


Cheers,
Tyler

 

[KmH]

+1 on the Whibal card. Using a gray card allows you to set a custom white balance, very handy if you have mixed lighting (lighting of different color temperatures).

One of the problems with using something white to set white balance is that our perception of white is 'managed' to an extent by our brain. Slight variations in white our eye detects, gets edited by our brains to pure 'white'.

So that 'white' napkin you grabbed to set a custom white balance was really 6.3% gray and that's why you've got a slight color cast in all your portrait images. :blushing: