Simple White Balance Questions

[doug_neeb]

I have a couple of questions about white balance settings. I know

that these sound very basic and simple, but I just need some

understanding.

 

First, I have a cardboard card that I have purchased. It is 18%

grey on one side and white on the other. I mostly know how to shoot

a card to use for a custom white balance. I certainly know how to

use my camera (Canon D30) to set custom white balance. But here is

the one place I seem lost. Am I better to shoot the grey side or

the white side? I mostly shoot HS football so it is always

outside..sometimes in daylight and sometimes under stadium lights.

I have been shooting the white side, and then using that image as

the custom white balance. I have just begun to shoot in RAW

format. If I shoot the grey side do I then just tell my camera that

the grey image is white? Sorry that doesn't seem to make sense to

me.

 

Second, and this should be quick. When I shoot the card to get an

image to use as custom white balance, do I shoot it with my camera

set to automatic white balance? In other words, what is the correct

white balance setting to use when shooting a white card?

 

Just confused.

 

And, thanks in advance for any help.

 

Doug

[Ed_Ingold]

Many writers recommend using an 18% grey card to set the custom white-balance curve. The rationale is that the exposure level is clearly in mid-range, the most important region for balance. It is also less likely to be affected by reflections than a white card. Only the curve is affected, not the sensitivity or ISO. Either way seems to work for me.

 

This is a calibration process, not auto-white balance. I'm not familiar with the specifics of the D30, but it is a custom function (menu) item in a D1x. It should not matter what white balance mode is present during calibration. Then you will set the white balance to a special mode to take advantage of this calibration, not auto-white-balance.

[rodolfo_negrete]

yea both cards are for diferent reasons. the gray card is to balance your exposure and the white one is to balance your light color cast.

I am sure yoy were confusing them .gray to take a rading or your exposure and the wihte to balnce your white balance.

[jimstrutz]

What Edward said.

 

It doesn't really matter which side of the card you use. You're not setting the exposure, just the color of the light. Whether it's white or grey, the camera is just adjusting for color not shading.

 

It won't matter what the white ballance is set to when you shoot your white ballance test/calibration shot either. Its preset color ballance setting doesn't effect the white ballance of the rest of the images no matter what it's set to.

 

If you are shooting in RAW format, none of the white ballance settings effect anything at all. You set the white ballance when you convert the RAW file. So it still doesn't matter.

[indraneel]

Shoot a raw image of the white card and use it to white balance your other raw pictures. You will need to shoot raw images of white cards if the light changes (sunrise/sunset). I find the coolpix 5700 to be balanced for daylight (ie no white balance required for RAW images shot in noon daylight).

[mjd]

Assuming no exposure correction is applied, the picture of the white card will look 18% gray anyway since that is how your meter is calibrated. It doesn't matter which side of the card you use as said above.

[rick_boone]

You may try using the Color Parrot. www.thecolorparrot.com. It's a new device to the market that is great for when a grey card can't quite do the trick, or isn't feasible to use.