Optics, exposure and astro toolkit
Photography Calculators
Free photography, video and optics calculators. Start with depth of field and ND time, then open NPF, flash guide number, timelapse and the rest of the field kit.
Optics & depth of field
DoF, hyperfocal distance, circle of confusion, macro DoF and diffraction limits.
Optics & depth of field
Circle of Confusion Calculator
Get a working CoC from sensor width and height using the 1/1500, Zeiss 1/1730 or 1/1000 diagonal conventions for DoF and hyperfocal math.
Optics & depth of field
Depth of Field Calculator
Work out hyperfocal, near and far sharp limits from focal length, f-number, focus distance and circle of confusion. Metres native; toggle feet on location.
Optics & depth of field
Diffraction Limit Calculator
Compare the Airy disk at your f-number and wavelength to CoC and pixel pitch to see when stopping down is CoC-limited or pixel-limited.
Optics & depth of field
Hyperfocal Distance Calculator
Find the hyperfocal distance from focal length, aperture and circle of confusion so everything from half that mark to infinity is acceptably sharp.
Optics & depth of field
Macro Depth of Field Calculator
Estimate total geometric DoF at close-up magnifications from f-number, magnification, CoC and pupil factor. Use it to decide whether to stack.
Exposure & light
EV, ND filters, exposure shift, flash guide numbers and the Sunny 16 rule.
Exposure & light
Exposure Shift Calculator
Keep the same exposure while changing aperture or ISO: get the shutter that matches, plus how many stops the shutter had to move.
Exposure & light
Exposure Value Calculator
Convert aperture, shutter speed and ISO into EV at ISO 100 and EV at your working ISO. Use it to match meter readings or compare two camera settings.
Exposure & light
Flash Guide Number Calculator
Turn a flash guide number, f-number and ISO into maximum subject distance, with GN scaled from the ISO 100 rating.
Exposure & light
ND Filter Exposure Calculator
Multiply a base shutter speed by 2 to the power of ND stops to get the long-exposure time in seconds, minutes and hours.
Exposure & light
Sunny 16 Calculator
Apply the Sunny 16 rule: f/16 at 1/ISO in sun, then shift shutter for slight overcast, overcast, heavy overcast, or sand and snow.
Sensor & focal length
Crop factor, equivalent aperture, angle of view, field of view and print size from megapixels.
Sensor & focal length
Angle of View Calculator
Compute rectilinear horizontal, vertical and diagonal angles of view from focal length and sensor width and height.
Sensor & focal length
Crop Factor Calculator
Get sensor diagonal, crop factor versus 36×24 mm full frame, and 35 mm-equivalent focal length from your sensor size and lens.
Sensor & focal length
Equivalent Aperture Calculator
Convert an f-number through crop factor into a full-frame-equivalent aperture and the DoF stop delta. Exposure on the sensor stays the f-number you set.
Sensor & focal length
Field of View Calculator
Turn focal length, sensor size and subject distance into frame width, height, diagonal and area in metres — useful for lighting and group shots.
Sensor & focal length
Megapixel Print Size Calculator
Turn megapixels, aspect ratio and DPI into pixel dimensions and print width/height in inches and centimetres. 300 DPI is the usual photo-lab start.
Astrophotography
500 rule, NPF, lunar eclipse and Milky Way starting exposures, and star-trail stacking time.
Astrophotography
500 Rule Calculator
Estimate the longest untracked shutter for stars with the 500, 300 and 200 rules from focal length and crop factor.
Astrophotography
Lunar Eclipse Exposure Calculator
Starting shutter for lunar eclipse phases from ISO and aperture: penumbral, partial, bright total umbra and dark Danjon totality.
Astrophotography
Milky Way Exposure Calculator
Starting Milky Way shutter from the 500 rule, a suggested ISO scaled from f/2.8 and 20 s at 3200, plus night EV at those settings.
Astrophotography
NPF Rule Calculator
Get a pixel-aware untracked star shutter from focal length, aperture, pixel pitch and an accuracy factor — tighter than the 500 rule on high-MP bodies.
Astrophotography
Star Trail Stacking Calculator
Work out stack length, sky-trail arc from Earth’s rotation and a 30 fps video duration from total minutes, interval and declination.
Timelapse & video
Timelapse intervals, file size, shutter angle, slow motion and drone mapping overlap.
Timelapse & video
Drone Mapping Overlap Calculator
Estimate camera footprint, photo grid and a 4000 px GSD from altitude, lens, sensor, survey area and front/side overlap.
Timelapse & video
Shutter Angle Calculator
Convert cinema shutter angle and frame rate into shutter time and reciprocal. 180° at 24 fps is 1/48 s.
Timelapse & video
Slow Motion Pacing Calculator
Find playback duration and slow-motion factor from how many seconds you record, the shoot frame rate and the playback frame rate.
Timelapse & video
Timelapse Interval Calculator
Turn shoot hours, interval and playback frame rate into frame count, clip seconds and clip minutes for a timelapse.
Timelapse & video
Video File Size Calculator
Estimate recording size from video bitrate in Mbps and duration in minutes, using decimal MB/GB (1000, not 1024).
Studio, storage & utilities
Card capacity, handheld shutter speed, inverse-square falloff, aspect crops and pinhole diameter.
Studio, storage & utilities
Aspect Ratio Crop Calculator
Fit a target aspect ratio inside a source pixel rectangle and see the cropped size, pixels kept and how much of the file you throw away.
Studio, storage & utilities
Handheld Shutter Speed Calculator
Get the classic 1/(focal × crop) reciprocal, that time in seconds, and the slower shutter IBIS buys you in stops.
Studio, storage & utilities
Inverse Square Law Calculator
See how light intensity falls when you move a point source: ratio of (d1/d2)² and the stop change of 2 log2(d2/d1).
Studio, storage & utilities
Pinhole Diameter Calculator
Find an optimal pinhole diameter from focal length and wavelength, plus the resulting f-number and Airy disk in micrometres.
Studio, storage & utilities
SD Card Capacity Calculator
Estimate how many stills and how many minutes of video fit on a card from capacity, still file size and video bitrate. Decimal GB.
Clusters
- Optics & depth of fieldDoF, hyperfocal distance, circle of confusion, macro DoF and diffraction limits.
- Exposure & lightEV, ND filters, exposure shift, flash guide numbers and the Sunny 16 rule.
- Sensor & focal lengthCrop factor, equivalent aperture, angle of view, field of view and print size from megapixels.
- Astrophotography500 rule, NPF, lunar eclipse and Milky Way starting exposures, and star-trail stacking time.
- Timelapse & videoTimelapse intervals, file size, shutter angle, slow motion and drone mapping overlap.
- Studio, storage & utilitiesCard capacity, handheld shutter speed, inverse-square falloff, aspect crops and pinhole diameter.