Lighting Ratio vs Silverlog Reciprocity

Lighting Ratios makes exposure calculations quick for photography and film lighting. • Calculate fill or background stops from any key light value • Enter key and fill stops to instantly get contrast ratios • Clear on-screen explanations with step-by-step math

Silverlog Reciprocity calculates corrected exposure times for long exposures on film, compensating for reciprocity failure — the point where film loses sensitivity during extended exposures. HOW IT WORKS Select your film stock from a comprehensive database covering Kodak, Ilford, Fujifilm, Fomapan, CineStill, Lomography and more. Enter your metered exposure time and instantly see the compensated time you should actually use. Calculations use manufacturer-published reciprocity data or established empirical formulas, and each correction shows which method was used: interpolation from a published data table, or a Schwarzschild exponent formula. FEATURES • Over 70 film stocks with reciprocity data • Instant calculation — no submit buttons, results update live • Method shown with each correction — data table or Schwarzschild exponent • Built-in countdown timer for the corrected exposure • Favourite and recent films for quick access • Works offline — no internet connection needed • Clean, focused interface designed for use in the field • Dark mode support BUILT FOR PHOTOGRAPHERS Whether you're shooting Velvia at sunset, Tri-X under moonlight, or Delta 3200 in a cathedral, Silverlog Reciprocity gives you the corrected time without fumbling with charts or guesswork. Part of the Silverlog photography toolkit. No account required. No data collected.