Custom WB - Gray cards?

[prodigy2k7]

So, I hear something about using gray cards to select the proper WB. Can someone direct me to a link that talks about WB and colored cards.

 

[Mike30D]

Grey Cards are NOT for white balance. Grey cards are for determining your correct exposure. To use one, have someone stand in the picture and meter off the grey card, that will give you a correct meter reading. Remove person and shoot picture.

White Balance has to do with determining the correct color temperature. Incorrect WB can produce unsightly blue, orange and even green color casts.
It's like back in the old film days when you were using daylight balanced film with tungsten lights.

There are quite a few tools out there to give yourself a custom white balance. The popular one is called ExpoDisc. There are also the collapsible ones that have a grey on one side (for exposure) and white on the other (for white balance).

 

[KhronoS]

For WB just use a plain white paper or something that it's white
That's what i use to color balance my light
The gray card it's for exposures, like Mike said.

 

[prodigy2k7]

oh ok, thanks, i must be getting them confused. How do I "meter" off the gray card? I dont think I have spot metering only partial metering on the XTi. I can change the WB using the presets but I dont know how to use custom WB, i can manually do it, but I dont know exactly how to make it good. Also, how do i use a white piece of peper for the WB? Using the custom WB on my camera?

 

[notelliot]

to meter with your gray card, set it up near your subject, select spot metering, and single-point focus, then point your camera at it and take the meter reading. you can do the same thing to read the shadows if you want to add fill-light, or balance your shadows and highlights in camera.

personally, for white balance, I stick to auto, unless I'm using strobes. quick and effortless lightroom adjustment.

 

[SpeedTrap]

Grey Cards are NOT for white balance.

Actually they are used for setting white balance, they have been being used to set white balace for decades.
You do not need an expodisk, a grey card will work fine,
I use one at all my shoots and I have never had a problem with incorect colour cast.

 

[Joves]

Actually they are used for setting white balance, they have been being used to set white balace for decades.
You do not need an expodisk, a grey card will work fine,
I use one at all my shoots and I have never had a problem with incorect colour cast.

Thank you I was going to say. I have heard of people using a white coffee filter like an Expodisc. Just put it over the lens and, measure the light away from the subject.

 

[RacePhoto]

Actually they are used for setting white balance, they have been being used to set white balace for decades.
You do not need an expodisk, a grey card will work fine,
I use one at all my shoots and I have never had a problem with incorect colour cast.

Ditto. This is where forums are flawed by misinformation. Grey cards ARE for white balance.

You can't use a white piece of paper, because white isn't always pure white. Some paper is yellow some has more blue, there are different brightnesses. You would be setting the white balance for that white, which could be introducing a color cast.

If you point a camera at a gray card and shoot fully on auto exposure, you will get a medium toned result. We know how bright the picture will be, so the only thing in question is what color it will be. Since the gray card actually has a neutral hue, any variation from neutral that the camera records must have come from the color of the light shining on it. To do this, it is important that the frame be completely filled with the color we are measuring to prevent reflections from other objects influencing it.

Link to full tip:

http://www.earthboundlight.com/phototips/white-balance-gray-card.html

And this on, on how to use them:

http://www.goshen.edu/~marvinpb/graycd.html

 

[Snyder]

I use Qpcard 101 (http://www.qpcard.se/BizPart.aspx?tabId=28) all the time. The less time I spend in post production the faster I can send up the image to be published and now a days any photo that is too late is old news.