Film Development – Temperature Time Calculator

Adjusts development time when temperature changes. Uses t₂ = t₁ · c^((T₁ − T₂)/10). Coefficient c = 2.5 (fixed; D-23 / D-76 / ID-11).

Base time at T₁ (20 °C)

Examples: 10:00 · 6:30 · 1:05:00 · 9.5 (minutes)

Actual temperature T₂ (°C)

Warmer → shorter time. Colder → longer time.

Standard temperature T₁ (°C)

Temperature coefficient c

c = 2.5 Fixed for D-23 / D-76 / ID-11

Factor: — t₁: — T₁: —°C → T₂: —°C

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Notes

Only adjusts for temperature. Agitation, dilution, and water quality also impact development.
Quick check: 10:00 at 20 °C → 25 °C with c=2.5 ≈ 6:20.