In order to get correct colors in digital photography, it is often necessary to use custom white balance mode. If you shoot in JPG, having the correct white balance is crucial since color adjustments in post-processing are very limited with JPG. Shooting RAW makes it possible to color correct any image, but it's better to have the correct white balance right in the camera, so you can see better preview of your images and save time in post-processing.
ExpoDisc is a well-known and widely used white balance correction tool. It turns your camera's reflected light meter into an incident one. ExpoDisc is a filter that you put in front of your lens to average out the light falling onto your subject. This gives you an average temperature of all light sources illuminating the subject. Thus, when using ExpoDisc, it is important to point your camera toward the source of light or the direction you're going to be shooting from.
ExpoDisc comes in several sizes to fit lenses of various diameters, including 52mm, 58mm, 62mm, 67mm, 72mm, 77mm, 82mm, and 95mm. (For this review, we used ExpoDisc 77mm.) While it's convenient to have the discs to match your lenses, it is not necessary to have more than one. You can get an ExpoDisc that matches your widest diameter lens and use it with lenses of the smaller diameters by simply holding the disc in front of them.
Also, there are two flavors of ExpoDisc: Portrait and Neutral. For more details please refer to ExpoDisc Portrait vs. ExpoDisc Neutral review
ExpoDisc features several spring loaded bearings that allow it to snap onto a lens of the matching diameter. There is no thread on the disc, so you don't have to screw it on. The attaching is as fast as it gets.
Each ExpoDisc comes with a nicely designed lanyard and a pouch. Having at least one of them is essential for being able to quickly access your filter.
If you decide to use the lanyard, make sure you adjust its length (or the length of your camera strap), so that ExpoDisc does not get in your way. Alternatively, you can put the disc in your shirt or vest pocket where it's easy accessible while still being attached to the lanyard. Also, the lanyard features a small clip that allows easy detaching of the filter when necessary (to put it into the pouch, for example).
The pouch is firm, and it provides good protection for the disc. It also has a loop on the back side to be attached to a belt. We find this very convenient and prefer using the pouch over the lanyard.
One of the popular ways of setting custom white balance is by using a gray card. Without a doubt, a high quality gray card does the job well. Not all gray cards, however, are calibrated and well manufactured. All ExpoDiscs are meticulously calibrated and well built.
Here are few advantages of ExpoDisc:
Thus, while a gray card is a good and usually cheaper way to set custom white balance, ExpoDisc delivers more accurate results, it is typically easier to use, and it is very likely to last longer.
Below, there are few examples of images taken in different lighting conditions with and without ExpoDisc.
The first pair of images are taken in broad daylight. Even though automatic white balance does a good job (left), ExpoDisc was able to remove a slight tint.
The mannequin shots below are taken with tungsten light studio softboxes. As you can see, auto white balance fails to produce correct colors while ExpoDisc delivers the spot-on result.
The last comparison was done in the rain at night. White balance was adjusted for car headlights, as they were the main source of light. The color cast in the left (auto white balance) image is apparent. The right image is more pleasant since the headlights look more neutral.
Thus, ExpoDisc is a high quality white balance tool that is built to last. It produces consistent results and works great in virtually any situation.
If you have any questions or comments, please post them below.