When you have been shooting for some time, using a gray card becomes a necessity rather than an option. This is especially true when shooting under artificial light, but the first question is why use gray cards in the first place?
Our own eyes are very good at adapting to different lighting conditions and we generally don’t notice subtle changes in the color of light. However, a camera will render these changing lighting conditions as either very blue or very yellow images.
The simplest way to correct this phenomenon is to take a quick snap of a gray card, note the white balance reading, then use that setting for the rest of your images. This process can be done either in-camera or after the event in software.
A gray card can also be used for setting the exposure and other color correcting issues. The ultimate aim of this process is to make sure all your images have accurate colors, which is just as important with black and whites images.
In the digital world, editing software like Lightroom freely allows you to play about with the white balance slider to achieve a neutral color balance. There’s also the option to select a white or gray part of an image or even eyeball the process by moving the white balance slider around. However, it is far simpler to use a gray card for the most consistent colors.
The common standard is to use an 18 percent gray card, which essentially reflects 18 percent of the light which falls on it. This standard was set back in the old film days and is used mostly for exposure. The ANSI standard for this value is actually 12 percent and some argue that for digital cameras, the value should be 25 percent.
This is why, on professional photo shoots, a lot of effort goes into achieving exact color rendition before the start of the process. Diving into the deep world of color theory and color temperature is beyond this article, but if you use one of the gray cards listed below, it will give you a good starting point for your own color optimization.
A pocket-sized gray card is a popular solution, with the WhiBal G7 White Balance Pocket Card being one of the best. Made from hard-wearing plastic, each card is spectrally neutral and is scratch and fade resistant.
The card has a target for easy focusing, with very low reflexivity, plus white and black patches for setting a true white balance reference. The card comes with its own keychain, making it quick and easy to use and break out at a moment’s notice.
When shooting with this card, all images can have their gray, black, and white points set very easily in software. This ultimately produces very accurate images in a very conveniently sized package. The unit also provides accurate readings with filters attached. If you can’t justify the price of the X-Rite ColorChecker, then this gray card is a good one to go for.
There are lots of options around for very basic gray cards, with the Kaavie 3 in 1 Pocket-Sized Reference Color & White Balance Gray Card Set having the three basic colors you would ever need.
The gray card has 18 percent reflectance, with the white version having 90 percent reflectance. These are all attached together with a nice little wrist attachment. The cards do a basic job of obtaining accurate white balance, but they are rather small and it takes a little practice to lock focus onto the things.
However, as a very simple and cost-effective solution, these cards are a good starting point.
The DGK Color Tools Optek Premium Reference White Balance Card Set comes with three color calibrated reference cards, carry strap, and user guide.
These cards are accurately set, along with being small and convenient to use. They are a branded version, which means that the gray points are more accurate than some of the more generic offerings on the market. These cards provide accurate color optimization and do exactly what they say on the tin.
Just like other plain faced gray cards, they have a blank surface, which means I usually draw a small target on each card. This allows autofocus to lock on to the card far more accurately.
5. Lightdow 12 x 12 Inch White Balance 18% Gray Reference Reflector Gray Card (Budget Winner)
While there are small gray cards which are just as cheap as the Lightdow 12 x 12 Inch (30 x 30 cm) White Balance 18 Percent Gray Reference Reflector Gray Card, this thing has a central target for AF systems to lock onto.
The gray side of this foldable unit has a 17.8 percent reflectance and comes with its own little carrying case. It can be unfolded and used with one hand and just as easily packed away. The other great thing is that it won’t degrade or warp over time as can happen with plastic versions if exposed to too much heat or light.
This unit, therefore, is very cost-effective, weighs next to nothing, and can be easily packed down into a camera bag.
Choosing the Best Gray Cards
On the surface, a gray card seems like a simple purchase. But, once you dig into the finer details of color profiling, all the solutions available are not made equally.
If you want the simplest and usually cheapest solution, the small pocket-sized gray cards can work very well. However, as in the WhiBal G7 White Balance Pocket Card example above, it’s better to have one with written on targets, measurements, and other readings.
As a one-stop solution to cover all color correcting needs, you simply can’t go wrong with the X-Rite ColorChecker Passport Photo 2. That’s if you don’t mind the initial asking price, but the results of this handy little camera accessory will be worth it.