Photography Calculators
Free, practical calculators for exposure, lenses, macro, output, cinema and optical imaging—plus printable lens test charts.
01Exposure & EVFind equivalent shutter, aperture and ISO settings, plus normalized EV₁₀₀.↗
02ND FilterConvert a metered shutter for stacked ND stops, density variance and timer use.↗
03Film ReciprocityEstimate seconds-to-minutes film correction from an emulsion-specific exponent.↗
04Exposure BracketingGenerate a centered HDR shutter sequence from frame count and EV spacing.↗
05Flash Guide NumberSolve manual-flash aperture, distance, ISO and power from guide number.↗
06Inverse-Square LightPredict illumination and stop change after moving a light or subject.↗
07Color TemperatureConvert Kelvin to mired and calculate the direction and strength of correction.↗
08SunlightEstimate sunrise, sunset, solar noon, golden hour and blue hour by place and date.↗
09Depth of FieldCalculate near/far limits, total depth and hyperfocal distance for a sensor and lens.↗
10Motion & HandheldChoose the faster shutter required by focal-length shake and subject movement.↗
11PanoramaPlan stitched coverage, overlap, frame count and resulting pixel dimensions.↗
12Astro ShutterCompare NPF and 500-rule limits using sensor size, aperture and pixel pitch.↗
13Star TrailsConvert a desired trail arc into shoot duration, frame count and duty cycle.↗
14TimelapseConnect event duration, interval, frame count, playback length and storage.↗
15MacroEstimate total magnification, sensor field width, effective aperture and light loss.↗
16Extension TubePredict added magnification, field width and exposure cost from extension tubes.↗
17Effective ApertureConvert marked aperture to close-focus f-number, bellows factor and stop loss.↗
18Focus StackingCalculate macro depth per frame, rail step, overlap and total stack count.↗
19Reproduction ScaleTurn subject size and frame fill into reproduction ratio and copy-stand geometry.↗
20Scan ResolutionConvert original size and scan DPI into pixels, file size and print potential.↗
21Pixel DensityDerive pixel pitch, Nyquist sampling and a two-pixel diffraction reference.↗
22Aspect Ratio & CropFind the largest target-ratio crop, retained pixels and final megapixels.↗
23Print & ResolutionTranslate pixel dimensions into print size, PPI and viewing-quality guidance.↗
24Viewing DistanceRelate print PPI to visual acuity, inspection distance and field of view.↗
25Storage PlannerCombine stills, video bitrate, card size and copy count into a storage plan.↗
26Shutter AngleConvert frame rate and shutter angle into exposure time and equivalent shutter speed.↗
27HMI Flicker-FreeFind mains-synchronized shutter angles closest to a creative motion target.↗
28AnamorphicCalculate horizontal spherical equivalence, desqueezed ratio and angle of view.↗
29Slow Motion & ConformConvert capture and delivery rates into playback speed, frames and screen duration.↗
30TimecodeAdd an integer non-drop duration to a starting timecode and frame count.↗
31Media RuntimeConvert codec bitrate and usable card capacity into runtime and data per minute.↗
32Film LengthConvert runtime and frame rate into film footage, metres, frames and roll count.↗
33Thin LensSolve image distance, extension, magnification and total conjugate length.↗
34Optical MagnificationMap object size to sensor fill, reproduction scale and ideal lens distances.↗
35Field of ViewCalculate horizontal/vertical angle and framed dimensions at a known distance.↗
36Lens EquivalenceMatch framing, depth of field and total-light exposure across sensor formats.↗
37Circle of ConfusionSet an output-aware sensor-plane blur criterion for depth-of-field calculations.↗
38Split FocusFind the widest aperture and focus point that keep two subject planes sharp.↗
39Close-up DiopterEstimate close-up-lens working distance, combined optical power and magnification.↗
40T-stop & TransmissionConvert f-number and transmission efficiency into T-stop and exposure loss.↗
41DiffractionCompare Airy-disc diameter with pixel pitch at normal or macro effective aperture.↗
42PinholeBalance geometric blur and diffraction to size a pinhole and effective f-number.↗
Method
Every tool gives the calculation, the assumptions behind it, a short reading of the result, and an in-field recommendation. Defaults are practical starting points rather than claims about a specific camera, lens, film, filter or lab.
Closely related tools are intentionally combined—for example hyperfocal distance lives with depth of field, while photo and video storage share one planning model.
About
PhotoForm covers six technical families: photo calculations, macro, pixel/output planning, cinema, optical imaging and lens testing.