Reciprocity Calculator

If it’s not on the list, then Generic color-negative film is a safe option.

Input the exposure time that the Light Meter gave you for a scene.

The calculator provides the adjusted exposure time accounting for reciprocity failure.

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Theory of Reciprocity Failure

• Film’s sensitivity decreases during long exposures, requiring longer exposure times than metered.
• Each film has unique reciprocity characteristics.
• Failure typically becomes significant at exposures longer than 1 second.
• Color shifts may also occur with color films during long exposures.

Tips:

• Always use reciprocity correction for exposures longer than 1 second.
• Bracket your corrected exposures ±1 stop when shooting critical work.
• Keep notes on which film stocks perform best for your typical long exposure work.
• For exposures over 10 minutes, consider the impact of changing light conditions during the exposure.

• Colour Negative Films

• 100 Classic
• 200 Creative
• 400 Action

• Neopan 100 Acros II
• Provia 100F
• Velvia 50
• Velvia 100

• Phoenix
• Phoenix II

• Delta 100
• Delta 400
• Delta 3200
• FP4+
• HP5+
• Ortho+
• Pan F+
• SFX
• XP2 Super

• Pan 100
• Pan 400

• Ektacolor Pro 160, 400, 800
• Ektapan 100
• Ektapan 400
• Ektapan 3200
• Ektar 100
• Kodacolor 100, 200
• Gold 200
• Porta 160, 400, 800
• T-Max 100
• T-Max 400
• T-Max 3200
• Tri-X 400
• UltraMax 400
• Vision Films

• RPX 25
• RPX 100
• RPX 400