Search Ctrl K
Home / Tools
THE FEUTEX TOOLKIT

ND Filter Long Exposure Planner

Calculate exposure duration after a neutral-density filter and display optical density.

Photography workspace● Runs in your browser
01 Your input
02 Your result
View or copy raw result data
FormulaFiltered shutter duration = time*2**stops; Optical density = stops*log10(2); Light transmission = 100/2**stops
Sources and model references

Worked example

Inputs

Unfiltered shutter duration
0.01 s
Filter strength
10 stops

Expected results

Filtered shutter duration
10.24 s
Optical density
3.010299957
Light transmission
0.09765625 %

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Calculate exposure duration after a neutral-density filter and display optical density.
  2. Set unfiltered shutter duration, filter strength in the indicated units.
  3. Calculate and compare filtered shutter duration, optical density, light transmission.

Try this example

{
  "time": 0.01,
  "stops": 10
}

Accuracy and scope

Idealized educational model. Enter measured values in the displayed units; real systems may require additional corrections.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.