Exposure / 01
ND exposure calculator
Extend a metered shutter time for a neutral-density filter. Add stacked filters by adding their stop values.
Darkroom desk / Tool cabinet 01
Photography tools
Work out the numbers before you load the film. These small field tools cover exposure, formats, focus and timing. Calculations run in your browser. Save this page to your Home Screen for quick access; core tools are designed to work offline once installed.
LIGHT LOSS
Exposure / 02
Long exposure & reciprocity
Combine a meter reading, ND filter and (for film) the correction published by the film maker.
Lens / 03
Focal length & format converter
Compare diagonal angle of view between film gates and sensor formats. The table shows the focal length that gives roughly the same framing.
Focus / 04
Depth of field & hyperfocal
Estimate near and far acceptable focus using a traditional circle-of-confusion calculation.
Sequence / 05
Time-lapse planner
Plan a sequence from capture interval, shooting duration and playback frame rate.
Exposure / 06
Exposure settings converter
Start with an EV100 reading, choose ISO and aperture, and calculate the matching shutter speed.
Flash / 07
Guide number calculator
Work out aperture, distance or guide number for a direct flash exposure.
Darkroom / 08
F-stop printing calculator
Adjust a base print exposure by fractional stops and build an even test strip.
Darkroom / 09
Darkroom process timer
Build and run a sequence for film, paper or another process. You supply the process instructions.
Darkroom / 10
Developer dilution mixer
Work out stock and water quantities for a chosen working volume.
Darkroom / 11
Formula book
Keep personal recipes on this device, record where they came from and scale ingredient quantities.
Made for the field
Large controls, short forms and readable results work on a phone screen. No account or connection is needed for calculations.
Use the figures as a guide
Film, filters, shutters and meters vary. Check critical exposures against your camera, film-maker guidance or a trusted meter.