What does the flash index mean?

Flash index is a parameter of camera or flash, which is used to describe the output power of flash. GN value, also called derivative, is usually used to represent the farthest effective irradiation distance of a flash lamp. The greater the GN value, the greater the irradiation range of the flash.

The importance of flash index is that it can be selected and adjusted according to different shooting requirements. For example, when shooting a scene that requires a strong light source, it is necessary to use a relatively large flash flash index; In some special cases, the flash index of the flash can be appropriately reduced to avoid overexposure.

In the actual photography process, the setting of flash index of flash will affect the quality of photos to some extent. Too high or too low flash index will cause distortion or insufficient light, which needs to be adjusted flexibly according to the specific situation. After mastering the basic meaning and application of this parameter, we can better control the shooting quality of photos.