Pinhole, worked out

The right hole for your camera

Enter the distance from the pinhole to the film and the format. The app gives the diameter to drill, d = c·√(f·λ), with the constant you choose from four published ones, and the f-number to the nearest third of a stop.

• Angle of view across the diagonal, the width and the height.
• Light fall-off towards the corners (cos⁴), and what a curved film plane changes.
• The thickness cut-off: how thin the material must be for the hole to behave as a pinhole.
• How sharpness changes with the distance to the subject.
• The needle and drill sizes that come closest to the hole you want.
• Measure a hole you have made from a scan of it.

The time, and the maker’s correction

Meter with the phone, or enter an EV or pick the conditions: the app gives the metered time, t = N²/2^EV · 100/ISO, for your hole and your film speed. Past a second film needs more light, so the app applies the maker’s own reciprocity correction and shows the metered and the corrected time together.

• Where a maker publishes nothing for a film, the app says “no published data” and shows no guess.
• Where a maker gives the correction only in stops of aperture, which a pinhole cannot open, the app shows the maker’s words and works nothing out.
• Nothing is worked out past the end of a maker’s table.

A timer for long exposures

Start the corrected time and leave the phone: a Live Activity and the Lock Screen show the time left, a haptic and a sound tell you when to close the hole, and the exposure log keeps what you did.

• Share the exposure log as a CSV file, only when you tap Share.

Your cameras, saved

Save each pinhole camera as a profile, with its distance, format and hole, and come back to it in the field. The app is in 13 languages.