Lighting Calculator
Calculate flash guide numbers, lighting ratios, and inverse square law for photography lighting.
Lighting Calculator
Distance = GN / Aperture
Flash-to-Subject Distance
7.14 m
f/5.6 at ISO 100
Guide Number Details
GN at ISO 10040
Effective GN at ISO 10040.0
Distance by Aperture
f/1.428.6m
f/220.0m
f/2.814.3m
f/410.0m
f/5.67.1m
f/85.0m
f/113.6m
f/162.5m
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
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Formula Source: Standard Mathematical References
by Various
🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.