Using a gray card is a fast and easy way to set an accurate white balance. A proper white balance eliminates unwanted color casts, so that, for example, skin tones are rendered more naturally and white objects remain a true white in your photos.
ProCamera has a built-in manual white balance feature, as well as an additional method for achieving white balance through what is called ‘gray card’ calibration. The neutral tone of a gray card serves as the reference point for this calibration. It is important that the gray card is positioned in the same light as your actual subject. For a manual white balance you need to switch from Auto to our manual M or semi-automatic SI mode. Tap the WB (White Balance) button on the capture screen to open the color temperature and tint dials – or tap and hold the WB button to perform a gray card calibration. The metered WB values will be locked for continuous shooting until you switch back to Auto White Balance by tapping the WB button again.
Furthermore, a gray card can be used to adjust the white balance in post-processing software. By having the gray card visible in one of your shots, you will later be able to select a point on the gray card in your image editing software in order to set a custom white balance.