18% Gray Card - Maybe a dumb question

[MohaimenK]

but I'll ask anyway (since I'm still a noob on it).

Is it a goodd idea to keep a copy of 18% gray card on your camera so incase you need to use it, just use that image to set the custom white balance? Or do you always have to hold the gray card in the environment you are on to get the correct lighting?

 

[Scatterbrained]

The whole point of a gray card is so you can set your WB and exposure for the ambient light. Keeping a copy of a gray card image in your CF card will be of no use since it will reflect the ambient lighting from the situation in which it was shot.

 

[MohaimenK]

The whole point of a gray card is so you can set your WB and exposure for the ambient light. Keeping a copy of a gray card image in your CF card will be of no use since it will reflect the ambient lighting from the situation in which it was shot.

I see! I wasn't sure if it was the same with a white card vs a gray card. Thanks for the quick reply! :thumbup:

Generally, if I am shooting landscape, should I use a gray card or that's only for shotting portrait or a certain subject?

 

[user3977]

noob here and not wanting to hijack this thread but i think it will help others like me.... what is a gray & white card for? im sure that someone will post "search you noob" and all but just a simple answer would be just as easy.

 

[MohaimenK]

noob here and not wanting to hijack this thread but i think it will help others like me.... what is a gray & white card for? im sure that someone will post "search you noob" and all but just a simple answer would be just as easy.

So you get more accurate white balance in your pictures. Ever took photos where the colors are way orr or your white t-shirt looks more gray?
Especially if you're indoor where the light is not as bright. As far as the difference, I THINK (not 100% sure) but gray will give you a better balance? But someone else can chime on that.

 

[Scatterbrained]

noob here and not wanting to hijack this thread but i think it will help others like me.... what is a gray & white card for? im sure that someone will post "search you noob" and all but just a simple answer would be just as easy.

Your camera's meter always tries to set your exposure so the the image is an overall 18% reflectance (light gray). Using a gray card will help you set your exposure because the camera will try and make the card appear as light gray, also it will set the white balance so that the card is 18% gray (vs blue or brown). Shooting a white card does the same thing, only you are setting your exposure so the white is perfectly white. I find a gray card to be easier as the camera is trying for gray anyway and some white paper is actually slightly yellow or blue which could mess your image up just enough that it won't look quite right.

If you have some time look up the X-rite color checker passport and watch the video. It is my personal favorite tool.

 

[KmH]

Gray is used because it has equal amounts of Red, Green and Blue.

18% reflectivity has little to do with color and more to do with the material used for setting a custom white balance, though the camera's meter is adjusted for 18% reflectivity it really depends what metering mode is used: spot, center-weighted, or Matrix/Evaluative.

I use the WhiBal card from www.rawworkflow.com and the same X-RITE ColorChecker Passport, Scatterbrained mentioned. www.xrite.com

 

[Robin Usagani]

LOL you are funny man! That would be a good blond joke for photographers.

 

[lunaaa]

LOL you are funny man! That would be a good blond joke for photographers.

You mean the OP?

 

[Robin Usagani]

yes

 

[MohaimenK]

yes

:thumbup:
Well sorry I am not as smart as you in photography then

 

[Robin Usagani]

LOL man.. everyone has their "Blond" moment .

yes

:thumbup:
Well sorry I am not as smart as you in photography then

 

[JClishe]

This brings up something that I've always wondered. How often do you guys use a gray card to set white balance? Every time you go out shooting? Or just when the ambient light is particularly challenging? Or not at all and just fix WB in PP?

 

[Petraio Prime]

noob here and not wanting to hijack this thread but i think it will help others like me.... what is a gray & white card for? im sure that someone will post "search you noob" and all but just a simple answer would be just as easy.

Your camera's meter always tries to set your exposure so the the image is an overall 18% reflectance (light gray). Using a gray card will help you set your exposure because the camera will try and make the card appear as light gray, also it will set the white balance so that the card is 18% gray (vs blue or brown). Shooting a white card does the same thing, only you are setting your exposure so the white is perfectly white. I find a gray card to be easier as the camera is trying for gray anyway and some white paper is actually slightly yellow or blue which could mess your image up just enough that it won't look quite right.

If you have some time look up the X-rite color checker passport and watch the video. It is my personal favorite tool.

Actually, no. Camera meters generally are calibrated for about 12-13% reflectance.

 

[MohaimenK]

This brings up something that I've always wondered. How often do you guys use a gray card to set white balance? Every time you go out shooting? Or just when the ambient light is particularly challenging? Or not at all and just fix WB in PP?

Doing research online, they say camera now days are about 99% correct with AWB but professional photographers will most likely do it for every environment they are in.