Manual Flash calculator GN 58

计算拍照在特定距离所需的闪光输出。

Calculates the flash output required to take a photo at a specific distance.

Many flash guns don't support TTL technology so it's necessary to configure them manually. The configuration could be done with reference to guide number table on the user manual. Alternatively with this application you can calculate the flash output to set to achieve the correct exposure.

You need to provide the distance of the subject the lens aperture and optionally the flash coverage and the camera ISO sensibility. Pressing calculate button you get the flash output setting you have to use and an indicator under or over exposure in stops.