WhiBal and color temperature
I picked up a WhiBal color balance card and, though I haven’t had the chance to do any really critical (or even really interesting) photography the past few weeks, it’s already given me great results with some easy, casual shots. White balance is one of those subtle things that’s hard to get right, but really stands out when it’s wrong. Fairly or not, when I’m looking a photographer’s work, it’s the first thing that gives me an impression of their technical skill.
The card is a small, neutral piece of plastic that you use to determine an accurate white balance, either with a custom white balance before shooting, or as a batch setting in post-production. It comes in several sizes; I got one about the size of a business card, because I do a lot of macro and wanted a smallish one, but for larger scenes Amazon carries a 3.5″x6″ Studio size, and there’s a wider variety directly from the manufacturer. It comes with a stand, a lanyard, and a thin, cheap-feeling case; they also make a really small one that attaches to your keychain. One nice aspect of the card is that the color comes from the material, not a printed surface, so any scratches won’t affect its effectiveness. There’s a sticker on one side that’s used for setting white and black points in post, and it has an autofocus target as well.
The WhiBal looks like a typical Kodak gray card used for exposure (in that both are gray rectangles), but the two are used for different purposes. A gray card has a standard 18% reflectivity, so your camera’s light meter gives you a consistent exposure with them. But they’re not entirely neutral in color, and they aren’t even the same color in different types of light — so using a gray card for white balance will give you the wrong color temperature, and it won’t even be a predictable amount of wrong in different situations. On the other hand, the WhiBal isn’t 18% gray, and using it for exposure will be a bit off; I’m not sure by how much, or how consistently, but I’ll bet you could experiment with exposure compensation to meter off the white and black sticker.
In a RAW workflow, you use the WhiBal by placing it in the scene you’re shooting, adjust the angle so you don’t see any glare on the stickers, and taking a shot of it. Then you go on shooting as normal. If the lighting conditions change, take another shot. Once you’re in post-production, you can use the “click white balance” tool of your digital darkroom on the card, and then copy that setting across all the images in those lighting conditions. All the software I’ve used has a batch-copy tool to make this simple. It’s supremely easy and consistent — it takes about five seconds to shoot the card, and another five to set the entire shoot’s white balance.
By the way, in case you’re interested, I’ve measured the color temperature of my Vivitar 285HV flash as 5750 degrees, with a tint of -2 in LR. My 40D’s on-camera flash measures 6400 degrees, with no tint adjustment.
The image of the robin above was balanced using the WhiBal card, and for the photography I do — which is very nature and animal oriented — it’s a great example of the card’s impact. Auto white balance was totally off. The Daylight setting I was shooting in was just slightly too warm, and like many images I’ve taken in the fall and winter, the dried leaves just looked subtly wrong. It’s not terribly visible in the comparison image, but it’s something that’s bothered me for a long time, and I picked this specific image because the WhiBal’s setting made the colors of the dead foliage feel “right” for the first time.
So the verdict is good. It’s easy to use, tremendously helpful, and not terribly expensive, even for a low-budget photographer like myself. I wish I’d gotten one earlier.