Traditional Culture Encyclopedia - Photography major - White balance a4 paper or grey card?

White balance a4 paper or grey card?

the gray card is good. The reflectivity of a4 paper is only 5, while the reflectivity of grey card is 9. Compared with a4 paper, grey card is more accurate and reliable. Grey card itself is a standard reference tool specially used in the field of photography, while a4 paper is only used as an auxiliary. The surface of grey card is uniform and the reflectivity is stable, which can provide more accurate white balance reference value, so grey card is good.