LONG EXPOSURE

ND Filter Exposure Calculator

Convert a metered shutter speed into the corrected exposure for any neutral-density filter from one to sixteen stops.

CORE FORMULAfiltered shutter = base shutter × 2ˢᵗᵒᵖˢInputs stay in this browser.

INPUTS

Set your shot

Unfiltered shutter denominator1/x secFor 1/125 s, enter 125. For 2 s, enter 0.5.Filter strengthstops

LIVE RESULT

Your working numbers

Filtered shutter time8.2 sec

Exposure multiplier1,024×

Optical densityND 3Equivalent to 10 stops

Metered shutter1/125 sec

Assumes aperture and ISO stay fixed. Round to an available shutter setting and verify with a test exposure.

READ THE RESULT

Use the estimate as a planning tool.

Camera specifications, tolerances and shooting conditions can change a real result. We expose the assumptions so you can choose a margin that fits the consequence of getting it wrong.

Read the related field guide