Most Neutral Gray Cards for Digital Photography

Do you think you have to pay a lot of money to get a good neutral gray reference? If so, read on. The best solution may be free, and it may come from a hardware store.

I am colorblind, and I am a professional photographer. That creates problems. It means that I need to have color references I can trust, because, if I do, I can use them to create images with pleasing, vivid and accurate colors. If my references are off, then my images will probably be too.

I wanted to know which of my available gray-card references was most accurate, so I decided to measure them using a Gretag Macbeth i1 Spectrophotometer that I have. The i1 isn't the world's most accurate Spectrophotometer, but it's better than what most photographers would have available. If someone wants to improve on this by providing better measurements with a higher-end tool, I'd love to hear about it.

The candidates and the i1 Spectrophotometer are shown in the image below. I used the i1 to measure the "color" of all of the choices, then summarized how much they deviated from a neutral gray in the table that follows. The gray references are the Lastolite Ezybalance (largest behind the others), the WhiBal White Balance Reference (smallest with the black and white areas), DGC-100 Digital Gray Card (medium sized -- all gray) and a Glidden Paint sample strip (Snowfield, Universal Grey, Veil, Granite Grey, Obsidian Glass, Dark Secret) from Home Depot.

The measurements surprised me. I would have thought that the photo-products would have outscored the paint sample, but that's not the case. The Glidden strip is more neutral in every case except for the extremes where "Snowfield" (the lightest color) and "Dark Secret" (the darkest color) are slightly less neutral than the DGC-100.
So, what's a photographer to do. Well, if you've got something that's working, stick with it. My measurements are the average of three measurements on a single product, and there may well be enough product variation that you've got "a good one." If you're looking to buy something new, you might just settle for the right Glidden paint strip in these tough economic times. I have to admit, I like the form factor of the Lastolite the best, but I've been using it less and less since I did these measurements.