Pinhole

A pinhole camera has a hole where the lens should be. Light passes through an opening well under a millimetre wide, so the picture is formed by geometry alone. There is no glass, so there is nothing to focus and nothing to focus on.

That gives a picture with no plane of focus. Everything is equally soft and equally in focus, from the near edge to the horizon, which is a state no lens can reach. The corners go dark, because the light that reaches them travels further and strikes the film at an angle. The frame shape is whatever the box is, and a pinhole box is often square or 4:5.

Say no lens, then say the hole. A pinhole camera, a hole rather than a lens, and an aperture somewhere between f/150 and f/350.

Ask for the softness to be even. Soft detail across the whole frame, no sharp plane anywhere, low contrast throughout. The absence of a sharp region is the thing a prompt has to state, because a model will otherwise pick a subject and sharpen it.

Say the exposure time and its consequence. Seconds to minutes, so water goes to a smooth sheet, leaves blur in the wind, and a person who walks through the frame leaves a faint streak or nothing at all. The vignetting is heavy and it darkens every corner, not one.

Use it when the picture is about time rather than about a moment: a long empty street, a shore, an interior lit by one window, a building with people flowing through it.

Leave it alone when detail matters. A pinhole resolves less than any lens ever made, and no wording gets the detail back.

Cinema publishes Deep Focus, Vignette, Motion Blur and Low Shutter at /techniques/cinema/ as four separate entries. A pinhole produces all four at once, and it produces them because it has no lens, not because somebody chose a setting. If a prompt only needs one of the four, the cinema entry is the cleaner tool.

Holga is the other soft camera on this page, and it is soft in a different way. A Holga has a plastic lens with a sharpish centre and smeared corners. A pinhole has no sharp region anywhere in the frame.

Large format 4x5 shares the tripod, the sheet film and the slow pace, and many pinhole cameras take 4x5 sheets. The result is the opposite: maximum detail on one side, minimum on the other.

David Brewster used the word pinhole in 1856, and the camera obscura it describes is older than photography by centuries. The method returned as a working practice in the 1960s and the 1970s, and it now has a date in the calendar: Worldwide Pinhole Photography Day runs on the last Sunday in April and was first held in 2001. Zero Image sells wooden pinhole cameras in 6x6 and 4x5, and Harman sold a 4x5 pinhole camera as a box with its own paper negatives inside.

The model returns a normal photograph with a blurred background. Say no lens, no sharp plane anywhere, and soft across the whole frame, all in one line.

The corners stay bright. Say heavy vignetting that darkens every corner, and say the fall off is strongest at the edges of the frame.