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View Poll Results: What do you use for custom white balancing
White card 3 21.43%
18% Gray card 1 7.14%
White printer paper 4 28.57%
18% Gray cloth 1 7.14%
Expodisc or similar White Balance filter/cap 2 14.29%
Other 3 21.43%
Voters: 14. You may not vote on this poll

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Old Jan 18, 2010, 12:11 PM   #11
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Yes, I guess having a WBD (White Balance Dog) is a little different compared most tools a camera owner would use for setting a custom white balance. I wonder if Chato has noticed this thread.

I actually use the inside top of one of my camera bags from time to time since it's a mid gray and seems to get it close. But, that's closer to the gray cloth method.

Maybe we should add gray and white fur choices if this type of poll is repeated at some point.
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Old Jan 18, 2010, 12:20 PM   #12
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Ok, this is a total newbe question. How do you know which color to use. On the one lens filter thingy, they had two different ones, people use white, grey.....
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Old Jan 18, 2010, 12:30 PM   #13
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A gray card is the preferred method. But, white can also work. They're both considered to be neutral (i.e,, equal values for Red, Green and Blue). For example, a mid gray may be somewhere around 118, 118, 118 (although you may see different values being used to account for the properties of the material it's printed on), whereas pure white is 255, 255, 255.

Because both have equal parts of red, green and blue, they should both work for setting your white balance (i.e., no one color should be absorbed or reflected more than another when measuring the temperature of the lighting from it).

I'm sure some of the members may understand the theory behind it better than I do. But, both are commonly used method for measuring the temperature of the lighting you're shooting in.
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Old Jan 18, 2010, 12:31 PM   #14
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Or just shoot RAW and use AutoWB, fix if necessary in Post. This has the big advantage because under certain (esp. cheap fluorescent) lights there is no way to set the WB accurately because it changes many times a second.

And if you're shooting under controlled conditions it's easy to fix/adjust batches in Post as long as you are using a decent tool like Lightroom, Aperture, Bibble, DXO, CaptureOne, etc.
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Old Jan 18, 2010, 12:52 PM   #15
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Quote:
Originally Posted by JimC View Post
A gray card is the preferred method. But, white can also work. They're both considered to be neutral (i.e,, equal values for Red, Green and Blue). For example, a mid gray may be somewhere around 118, 118, 118 (although you may see different values being used to account for the properties of the material it's printed on), whereas pure white is 255, 255, 255.
P.S.

What a camera is actually doing when applying a white balance to images is using RGB multipliers.

So, when you take a custom white balance reading from a neutral target, and the camera sees differences between the proportions of red, green and blue it's measuring in the lighting you're shooting in (because of the temperature of the lighting), it can determine what RGB multipliers to apply to the images you take in that lighting.

Basically, that's what you'll find in raw files for the "as shot" white balance settings (all they are is a set of RGB multipliers that a raw converter can choose to apply to the image or not if you want to use the settings the camera had when the images were taken).

Virtually all camera manufacturers use the same technique (store the actual RGB Multipliers they want to apply later).

The raw converter then applies these RGB multipliers (for example, 2.15, 1.1, 1.27) to the red, green and blue channels of an image during the demosaic process if you elect to use the "as shot" white balance (versus setting it yourself).

If you want to see the multipliers being applied, some raw converters can show you that information (for example, UFRaw shows you the RGB multipliers being used if you go to the screen for setting WB and you can see how your changes impact the "as shot" multipliers it found in the metadata)

When you shoot JPEG, the camera is just applying those multipliers during processing of the images. If you shoot raw, most converters will let you use the multipliers the camera would have used if shooting JPEG, or change them to something else as desired.

Most show a color temperature reading for that purpose, too (so you'll know what the temperature of the lighting should be using a given set of multipliers), sometimes with sliders for additional offsets. But, what the converter is actually doing is applying a set of multipliers to the RGB channels.
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Old Jan 18, 2010, 1:39 PM   #16
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Quote:
Originally Posted by TCav View Post
... like Chato's WBD?
Got that right! I just voted, and picked "other." And you bet, my faithful White Balance Dog (Patent Pending) is my tool of choice.

(In all seriousness, I DO use Chato to set WB)

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Old Jan 18, 2010, 1:43 PM   #17
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Quote:
Originally Posted by peripatetic View Post
Or just shoot RAW and use AutoWB, fix if necessary in Post. This has the big advantage because under certain (esp. cheap fluorescent) lights there is no way to set the WB accurately because it changes many times a second.

And if you're shooting under controlled conditions it's easy to fix/adjust batches in Post as long as you are using a decent tool like Lightroom, Aperture, Bibble, DXO, CaptureOne, etc.
I wouldn't use Chato if I didn't shoot RAW. Personally I find that correcting WB after loading an image into an image processing programs never works quite right. Chato, is White, of if in shadow partialy gray, or something in-between. He's a very flexible tool...

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Old Jan 18, 2010, 1:47 PM   #18
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Quote:
Originally Posted by Chato View Post
Got that right! I just voted, and picked "other." And you bet, my faithful White Balance Dog (Patent Pending) is my tool of choice.
I dunno. That patent application may be disputed because of similar prior art, due to patents pending for the use of a WBC (White Balance Cat). ;-)
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Old Jan 18, 2010, 2:16 PM   #19
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Quote:
Originally Posted by JimC View Post
A gray card is the preferred method. But, white can also work. They're both considered to be neutral (i.e,, equal values for Red, Green and Blue). For example, a mid gray may be somewhere around 118, 118, 118 (although you may see different values being used to account for the properties of the material it's printed on), whereas pure white is 255, 255, 255.

Because both have equal parts of red, green and blue, they should both work for setting your white balance (i.e., no one color should be absorbed or reflected more than another when measuring the temperature of the lighting from it).

I'm sure some of the members may understand the theory behind it better than I do. But, both are commonly used method for measuring the temperature of the lighting you're shooting in.

But then there is the school of thought the camera makers cal to ANSI specs. And 18% gray is not the idea thing for WB. I really do not know which school of thought is more accurate? But I go with what I have learn form years ago and have serve me faithfully thus far. But gray 18% gray card and cloth allow you to pack one items and have it sure double or triple duty. So you can do exposure lock, wb, and with cloth clean the lens. Me I just use a white card for wb, and the palm of my hand to do exposure, just add 1 full fstop darker.
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Old Jan 18, 2010, 2:19 PM   #20
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Actually, from what I understand 11% gray is what meters should be calibrated to use for exposure, even though 18% is what you see posted everywhere and that's the way gray cards are manufactured. :-)

See this article discussing it:

http://www.bythom.com/graycards.htm
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