Bellows Extension & Exposure Factor Calculator

Precision exposure compensation for large format macro photography.

Parameters

Why compensate?

When extending bellows for macro work, light intensity at the film plane decreases as distance increases. Use these values to adjust your shutter speed or aperture to avoid underexposure.

Calculation Results

Stops to Add

2.0

EV adjustment required

Exposure Factor

4.00x

Multiplier for time

Common Factors

Ratio (Ext/FL) Factor Stops
1.2x1.44x0.5
1.4x2.00x1.0
2.0x4.00x2.0
3.0x9.00x3.2