Strobe Aperture Setter
Pick a starting strobe setting for the f-stop you want.
Required guide number
16.0 (m @ ISO 100)
Effective GN (at ISO)
16.0
Modifier loss
-2 stops
Verdict
Insufficient power — increase ISO or move closer.
Note
Always meter on location — these are starting points.
About this tool
Inputs: ISO, desired f-stop, distance, modifier. Outputs: required guide number, effective GN, modifier loss, verdict. Targets r/photography Sekonic manual-strobe thread.
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