Introduction

Photography depends on the quality of light and color. Only well adjusted colors can make a photograph pleasant to look at. White balance is the key, but many digital photographers don’t pay enough attention to it as they wrongly assume that they can fix it in post production. However, without a neutral reference point, this is impossible. That is why the use of white balance tools is imperative for high-end digital photography. The gray card, ColorChecker passport and the ExpoDisk are professional tools to create such a neutral reference point.

Gray Card

A standard 18% middle gray card is first and foremost a tool for measuring the exposure or calibrating black and white film development according to the zone system. Some photographers use it as a white balance tool as well. They take a digital image of the card in the scene and in post production, they use this reference image to set the white balance. Depending on the image processing program, a white balance picker can be placed on the card in the frame and the resulting measurement is then applied to all subsequent RAW-files shot under the same lighting conditions.

This process can be called reflective method, as the idea is that all the various light sources with different color temperatures reflect onto a neutral surface, therefore providing a neutral reference.

Unfortunately, the assumption that a regular gray card for exposure metering is free of color tints can be wrong. I strongly advice against using a regular gray card for setting the white balance unless it is specifically designated as color neutral.

ColorChecker

A specialized tool for the reflective method is the ColorChecker by Calibrite. The passport version has a hard plastic shell containing four reference surfaces. One combination consists of a gray card (18%) patch and a tint-free, perfectly neutral white balance patch. An image of the card has to be taken so that it can serve as a white balance target for the RAW-images in post production.

It is worth mentioning that the second combination of reference patches offers more specialized white balance options. A set of warmer and cooler reference patches allows for shifting the white balance and therefore the color look in a controlled way. Creating a personalized, cooler or warmer color tone consistently under different lighting conditions becomes a repeatable process with these reference targets.

ColorChecker Passport - advanced white balance reference patches and camera profiling patches.

ExpoDisc

Two versions of the ExpoDisk as well as numerous third party copies of varying quality were released over the years. The ExpoDisk is a calibrated incident white balance filters that works similarly to incident light meters. By holding the filter disk in front of the camera’s lens and pointing it towards the main light source, a white balance reference image can be taken to either set the white balance in camera or to create a reference image for later use. I recommend always doing both.

With some practice, the photographer is able to determine at which light source the ExpoDisk should be aimed at to get the best result. Depending on the circumstances, it might be necessary to take the subject’s position to get a proper reading.

Some photographers point the ExpoDisk at the scene to get an average reflective white balance reading. I cannot recommend this method as the results depend on the colors present in the scene and therefore vary from one set to another.

Test Scenes

The scene below was lit by window light.

The scene below was lit by window light and a warm LED.

The scene below was lit by window light, a warm LED and a cold LED.

Verdict

Both methods of setting the white balance work very well.

However, for some scenarios, a reflective white balance tool is preferable over an incident tool. For example, when shooting with on-camera flash it is impossible to get a reading with the ExpoDisk. Incident tools are also not recommended when the distance between the light source and subject is too short, like in macro or reproduction photography. The camera might not be positioned in a way to take a reading.

The ExpoDisk has its individual strengths as well. The possibility of setting the white balance in camera gives an accurate preview on set and for landscape and outdoor photography, the incident method is very convenient. Also, the original ExpoDisc can be used as a diffuser, converting the camera’s internal light meter to an incident light meter of sorts.

I primarily use the ColorChecker passport as I found it to be more suitable for my type of work. However, I also own an ExpoDisk as both tools have their unique strengths and use cases.

Also on YouTube

White Balance Tools