I am a small white SLR photographer. Recently, when I was watching some photography experience sharing, I saw such a passage: when shooting portraits in reverse light, use a flash to synchronize the s

I am a small white SLR photographer. Recently, when I was watching some photography experience sharing, I saw such a passage: when shooting portraits in reverse light, use a flash to synchronize the speed. One of the most basic parameters of flash memory is flash memory index. Such as 32, 24, etc. If the portrait taken by the flash is neither "up" nor "down" when shooting a portrait in the backlight, it is necessary to accurately predict the distance between the camera and the subject, which is determined by the flash index and aperture value. Here is a formula: shooting distance = flash index divided by aperture value.

Manual shift (M) for general SLR cameras. Specific steps: 1, (assuming your camera flash synchronization speed is1125 seconds), set the camera aperture to F8; 2. (Suppose your flash index is 24) Divide 24 by 8 to get that the distance between the camera and the subject is 4 meters, and adjust the focal length of your camera to 4 meters; 3. shoot.