Home Made Grey Card

[martcol]

If I fill a page with 15% Gray in MS Word will that make a good enough Gray Card for my White Ballance?

If I'm being totally stupid here, I do like to be told but gently! 8)

Martin

[ssim]

If I was you I would buy one from a camera store. They are not expensive.

[daveh]

That really depends on the accuracy and the nature of your printer/inks. (Why 15 rather than 18?)

Anything can be used a reference, but if you're not using a well-designed standard (like 15% instead of 18% and perhaps blacks that are a little on the warm or cool side) you may need to adapt to that reference rather than using it as simply as a well-made gray card.

Even "real" gray cards vary somewhat but probably less than your home-made card will. Then again, in a pinch, my hand is my gray card ;)

[slejhamer]

Why are you using a gray card to set white balance?

[robertwgross]

The 18% gray card is what you are supposed to use to set white balance. It does not matter so much whether it is 18% or 15% or even 1%, but the standard gray card is completely neutral for color.

You can use a completely white sheet of paper if you need to, but the white paper tends to reflect color from nearby. The gray card tends not to do that, so it tends to be the perfect neutral target.

---Bob Gross---

[slejhamer]

Thanks Bob, but the 10D owner's manual states that a white sheet of paper is what you are "supposed to use." :)

I've always thought that 18% gray cards are for setting exposure, not WB.

Also, wouldn't you want to neutralize those nearby colors that are being reflected by the white sheet? If they are not incorporated into your custom WB setting, would they not affect the color tone of the image?

Or is it just that the difference in reflectivity is so small that it is more convenient to use the gray card to set both exposure and WB at the same time?

[daveh]

slejhamer wrote:
Thanks Bob, but the 10D owner's manual states that a white sheet of paper is what you are "supposed to use." :)

Gray is sometimes better for setting "white balance" because it won't blow-out.

Whether/how much to incorporate surrounding dominant colors is a tricky question.

[robertwgross]

slejhamer wrote:
Thanks Bob, but the 10D owner's manual states that a white sheet of paper is what you are "supposed to use." :)


When did the discussion get limited to the 10D ?

---Bob Gross---

[slejhamer]

robertwgross wrote:
When did the discussion get limited to the 10D ?




It didn't. I was simply giving a published reference as context for my subsequent questions.


daveh: thanks; that makes sense.

[jimmyd]

Hello! I'm new to the forum and I'm a brand new owner of a 10D. I am both a videographer and a photographer, but primarily I'm a videographer. It seems to me that digital photography is more akin to digital videography. Assuming I'm correct, you would be best served using a white sheet of paper for white balance. There are alos gels (like 1/8 blue) that can be put over the lens when you white balance to a white card. This, for instance, will give warmer flesh tones in daylight.

[carnagex2000]

why not just open the image in photoshop, and go to image/levels and use the grey dropper to set white balance???