I have had gray cards forever and never bothered to use them, dumb idea!! These things are great!

A gray card is just that…a gray card. The color is a “medium gray” according to your camera’s reflective light meter. I’m not very science-minded so you’ll have to do a quick google for complexities beyond that but what I do know is that if you implement this little bugger in photography where color correctness is key (which is like, most photography) like food photography.

Knitting is a major hobby of mine aside from photography, I’m just as obsessive about fiber as I am about photos. Both are expensive hobbies that cause my husband’s eyes to glaze over when I talk about.

When I post my WIPs (that’s works in progress for you non-knitters) to Ravelry (biggest/best knitting community evar) I really hated putting that “color isn’t exact” disclaimer in the notes on my project pages. I see your eyes glazing over photogs, stay with me! Yarn color is a big party of the creative process when you select a pattern to knit, so I want to show it off right!

Here’s the sample image, I used the eyedropper white balance tool in Adobe Camera Raw CS4 to get the proper slider numbers…

And here’s the color correct photo. I used the numbers I got from the eyedropper white balance in ACR and set a custom white balance:

And here’s the straight from the camera jpeg for comparison:
(with my camera set to Auto White Balance)

Here’s another example where the difference is even more striking. Food is another form of photography that I can never seem to get “perfect” with AWB or even the sliders in Lightroom/ACR.

Sample image, corrected with the eyedropper clicked onto the gray card:

Corrected image…yum…(that’s sun dried tomato pizza btw):

And the SOOC jpeg on AWB:

Pretty cool, eh? I think I’ll be using cards more often!