Silverlog Flash

Silverlog Flash calculates flash exposure using guide numbers — the fundamental relationship between flash power, distance and aperture. HOW IT WORKS Choose what to solve for and enter the other two values. Find the aperture for a given flash-to-subject distance, the maximum distance for a given aperture, or the guide number from a known distance and aperture. Adjust ISO to see how sensitivity affects your working range. FEATURES • Guide number to aperture calculation • Guide number to maximum distance calculation • Guide number from distance and aperture • ISO adjustment • Metric and imperial distance units • Works offline — no internet connection needed • Clean, focused interface • Dark mode support USEFUL FOR • Manual flash photography without TTL • Working out flash-to-subject distance for off-camera flash • Understanding your flash's effective range at different apertures • Film photographers using manual flash units Part of the Silverlog photography toolkit. No account required. No data collected.