Why are all gray cards different colors? And which to get (for exposure)

[GregR]

I checked some gray cards yesterday. Each was at least a different shade of gray, and some appeared to be different colors - a reddish or blueish tint. I'm not talking about 12% vs 18% either, some difference were subtle, others more pronounced, but all were "18% gray cards".

The brands I checked were Xrite, Spyder, Lastolite (Ezybalance), QP Card (203), Novoflex, Ginichi, and some others. Surely if all are different then only one is correct?

Eitherway, which brand/model do you recommend for setting exposure (not WB)? Smaller is better, and 12% is preferable.

Thanks

 

[donski]

If it's for exposure, shouldn't it be a white card instead?

 

[GregR]

If it's for exposure, shouldn't it be a white card instead?

No, that would underexpose your images. Camera's see 18% gray (or 12% if you like). This is a topic on its own.

 

[kodiak]

No, that would underexpose your images.

You got that right for sure!

Hi Greg,

There are two tools: the WB card and the exposure card.

The WB card
Once your camera profile is in your RAW converter, you use the WB card
as a white or grey or black reference in whatever situation you shoot. See:
https://www.nikoncafe.com/threads/worst-possible-conditions.275734/#post-3546941

The EXPOSURE card
It doesn't matter if a tint is apparent since the only thing that counts is the B&W 18%
reference. In your RAW converter, reading this reference excludes the colour parameter
a consider only light 0r luminosity.

I am using something like:
http://www.amazon.com/X-Rite-MSCCPP-ColorChecker-Passport/dp/B002NU5UW8/ref=sr_1_13?ie=UTF8&qid=1391407436&sr=8-13&keywords=color card photography

 

[Growltiger]

I recommend you get a neutral grey one you can use for WB as well. Xrite offer exactly that.

 

[Butlerkid]

You got that right for sure!

....

I am using something like:
http://www.amazon.com/X-Rite-MSCCPP-ColorChecker-Passport/dp/B002NU5UW8/ref=sr_1_13?ie=UTF8&qid=1391407436&sr=8-13&keywords=color card photography

I, too, use the Color Checker Passport and find it very helpful!

 

[GregR]

The EXPOSURE card
It doesn't matter if a tint is apparent since the only thing that counts is the B&W 18%
reference. In your RAW converter, reading this reference excludes the colour parameter
a consider only light 0r luminosity.

Thanks Kodiak, that explains the color variations.

It seems from the other posts that Xrite is the way to go; however, the "gray" card on the ColorChecker Passport that I saw was almost white, and the documentation states that it is (only) for WB, which makes sense. I know the larger ColorChecker targets have an 18% gray card option, but this is a little too big at the moment. Are there 18% gray card options for the ColorChecker Passport? I couldn't see anything on the website - just the 4 x 7" card.

In the meantime, I might pick up the plastic Novoflex card, which I can cut to size, and later get a ColorChecker. But I'm still open to other options

I also must add, that I want to use the card to set exposure in the field, as opposed to in a RAW editor, as I often work in manual mode.

 

[kodiak]

Are there 18% gray card options for the ColorChecker Passport?

The link I supplied shows thumbnails beside the main photo,
the last one shows the larger "page" of the passport with the grey card.
There is even a good, clear video as well!