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Prise de vue · 2026-09-12

Building a 35mm Pinhole Camera and Making Your First Lensless Images

Pinhole photography strips the whole process down to its bare essentials: a light-tight box, a tiny hole in a piece of aluminum, and a piece of film. No glass, no lens, no focusing. And yet the images that come out have a quality you simply can't replicate with even the finest optics, a softness and a near-infinite depth of field that's entirely their own.

It's also one of the most accessible things you can do in analog photography. The basic materials cost almost nothing. You can build one in an afternoon. What takes time is getting your head around the aperture calculations and learning to work with exposure times measured in seconds or minutes rather than fractions of a second.

What a pinhole actually is

The principle goes back to the camera obscura: light passing through a very small hole projects an inverted image on the opposite surface. The smaller the hole, the sharper the image, up to a point. Below a critical diameter, diffraction takes over and the image starts going soft again. So there's an optimal diameter for any given hole-to-film distance, and that's where the math comes in.

The classic formula, derived from Lord Rayleigh's work, gives you the optimal pinhole diameter:

d = 0.036 × √f

where d is the hole diameter in millimeters and f is the distance from hole to film, also in millimeters. For a 35mm pinhole with a 50mm hole-to-film distance, that works out to roughly 0.25mm. For a 4×5" camera at 100mm distance, you're looking at around 0.36mm.

The effective f-number follows simply from there: f/ = f ÷ d. With those two examples, you get f/200 and f/278 respectively. These are very small apertures, which is exactly why exposure times run so long. On a bright sunny day, at f/200 with ISO 100 film, you're easily looking at 2 to 4 seconds. Overcast or indoors, think minutes.

Optimal pinhole diameter as a function of hole-to-film distance Hole-to-film distance f (mm) Diameter d (mm) 50 100 150 200 0.25 0.36 0.45 50mm / 0.25mm 100mm / 0.36mm
Qualitative curve of optimal pinhole diameter (d = 0.036 × √f). Values at f = 50 mm and f = 100 mm are exact; intermediate shape is illustrative.

Building a 35mm pinhole camera from cardboard

What you'll need

  • A rigid cardboard or thin wood box (an old shoebox, a cigar box, or a metal tin all work)
  • Matte black paint or black flock paper for the interior
  • A sheet of aluminum from a drink can, flattened out
  • A fine sewing needle or compass point
  • Very fine wet-and-dry sandpaper (1000 grit or higher) to thin the aluminum at the hole site
  • Rigid black cardboard for internal baffles
  • Black gaffer tape or matte black tape
  • Two 35mm spools: one loaded with film, one empty to take up the exposed roll

Building it

The box has to be completely light-tight. The interior needs to be painted entirely in matte black or lined with flock paper to kill any stray reflections that would wreck your contrast.

The front panel gets the pinhole: cut a roughly 15mm square opening in the cardboard, then cover it with your piece of aluminum, which you'll have already drilled. The secret to a good pinhole is working with aluminum that's been thinned right down first. Sand the spot with your fine paper until it's almost translucent, then work the needle through gently with a rotating motion, no forcing. A good hole is circular with no burrs. Hold it up to a lamp and check it: it should be clean and even all the way round.

To house 35mm film, you need compartments on each side of the film plane, with a simple advance mechanism: a rod for the take-up spool (a straightened paperclip or a wooden dowel works fine) and ideally a small counting window on the back. In practice, a lot of people just work blind, advancing a fixed amount between frames in a darkroom or under a dark jacket.

Cross-section diagram of a 35mm pinhole camera showing key components Supply spool Take-up spool Film Film plane ⌀ Pinhole Shutter Baffle
Simplified cross-section of a DIY 35mm pinhole camera — supply spool (left), pinhole front panel with shutter flap, optional baffle, film path, and take-up spool (right).

The film plane

The surface where the film rests has to be perfectly flat. If the film bows, the image will be sharper in the middle than at the edges. Some builders cut a shallow channel into the cardboard to guide the film and hold it flat.

The 4×5" version

If you have access to a view camera or a standard bellows, a 4×5" pinhole is even simpler to make. Cut a piece of cardboard or thin sheet metal to standard lensboard dimensions, mount your pinhole on it, and slot it into the bellows. You use regular 4×5" film holders from there. The big advantage of large format for pinhole is that contact prints are already at final size, and the results can be genuinely spectacular.

Choosing a film stock

Pinhole photography suits slow to medium-speed black-and-white film particularly well. Partly because the long exposures already smooth out minor variations in light, and partly because slower films tend to have finer grain and a latitude that handles extended exposure times more gracefully.

Orthochromatic films are worth mentioning here. Something like Ilford Ortho Plus 80 is insensitive to red, which darkens skies and gives slightly different tonal renditions. Combined with the inherent softness of a pinhole, it produces images that can look remarkably close to late-19th-century photography. For a first roll in 35mm, Kodak T-Max 100 or Ilford FP4 Plus 125 are solid, predictable choices.

The real issue with very long exposures is reciprocity failure. Beyond a few seconds, the film's effective sensitivity drops, and the nominal exposure time is no longer enough. You need to extend it according to the manufacturer's reciprocity curves. As a rough guide, Kodak T-Max 100 and Ilford Delta 100 handle long exposures relatively well, while Kodak Tri-X needs more significant corrections for really extended times. Check the technical data sheets before you head out.

Film stock ISO Type Reciprocity handling
Kodak T-Max 100 100 Panchromatic B&W Good for long exposures
Ilford Delta 100 100 Panchromatic B&W Good for long exposures
Ilford FP4 Plus 125 125 Panchromatic B&W Predictable, solid latitude
Kodak Tri-X 400 400 Panchromatic B&W Needs significant correction
Ilford Ortho Plus 80 80 Orthochromatic B&W Old-world tonal rendition

Metering and calculating exposure

Without a built-in meter, you have to work a bit differently. The most reliable approach is to use an ordinary light meter or a phone app, read the EV, then translate that reading for your effective aperture.

If your meter says 1/100s at f/8, you can work out by hand what that translates to at f/200. Every time you double the f-number, exposure time multiplies by four. In practice, note down your pinhole's aperture and use a conversion table or a dedicated photo calculator. Keeping a written log of every exposure is essential at the start, especially if you want to understand after development what worked and what didn't.

Development and printing

Developing film shot through a pinhole is no different from any other black-and-white development. Same developers, same times, same temperatures. If you're already developing at home, there's nothing new to learn on that side.

The one thing that might look different is grain, which can appear more pronounced depending on the film and how long the exposure ran. That's rarely a problem; it's often exactly what pinhole shooters are after.

For printing, a 35mm pinhole negative scans like any other. For 4×5", contact printing is the natural and very satisfying option. And if you have an enlarger set up, you can print the 35mm negatives normally too.

Ondu, Zero Image, and the commercial alternatives

If building one doesn't appeal to you, or you just want something reliable straight out of the box, two makers come up again and again in the community.

Ondu (a Slovenian brand) makes handcrafted wooden pinhole cameras in 135 (35mm), 6×6, 6×12, and 4×5" formats. The 135 model can even shoot 72×24mm panoramic frames by removing the internal dividers. Build quality is excellent and the design is genuinely beautiful.

Zero Image (Hong Kong) is consistently cited for the precision of its pinholes and the sharpness of the results. Every camera is laser-drilled and ships with a detailed spec sheet. These are the precision instruments of the pinhole world, and they're priced accordingly.

Going further

  • Ilford Ortho Plus 80: an orthochromatic film stock available in 35mm and large format, well suited to that old-world look. It develops in most standard black-and-white developers with times close to FP4 in the same chemistry.
  • Pinhole Designer (free software): a calculator where you enter your focal length and it gives you the optimal hole diameter and effective f-number. Worth having to avoid guesswork at the building stage.
  • Contact printing in large format: if you move up to 4×5" or 8×10", contact printing becomes the natural extension of pinhole work. The home black-and-white development article on this blog covers film processing basics, and the contact printing article walks through the darkroom procedure step by step.

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