THE 35mm PINHOLE CAMERA.

Many of our first attempts at pinholing involve replacing the lens of an SLR with a pinhole. The results obtained are usually very disappointing owing to the mirror housing inhibiting the short local length’ required for ‘sharp’ pinhole photography.
A pinhole 5 cm from the film plane produces an image of 15cm diameter. To make full use of the 24x36mm area of the 35mm format, the pinhole should be 1cm from the film.
This homemade camera makes use of this format by assembling a pinhole on the back of a cheap plastic 35mm camera, and flipping the film upside down. Exposure is done through the rear of the camera, so making use of its wind-on mechanism.
With care, the results obtained not only exploit the unique qualities of the pinhole, but can also produce sharper images than many lenses.

Construction.

1. Find a point and shoot plastic 35mm camera, (£1 -00 each at car boot sales, junk shops or join a bank!)
2. Using a small drill and a hacksaw, remove the pressure plate and cut a 24x36mm opening in the back.
3. Build a 7mm high mount out of black card.(See Photo)
4. Make the aluminium pinhole.

* Cut a square of aluminium from a drink can.
* Use a needle file to remove the paint from the central area.
* Get a sharp pin and very gently puncture the filed-down area, so that just the very tip penetrates the metal.
* Use 1200 grit emery paper to remove the rough edge on the non-paint side. This also removes the plastic coating found on the inside of cans.
* Check its size, using a ruler and a magnifier The hole should be about .25mm in diameter and can be checked by viewing the hole next to a mm gradation on a ruler. The hole should fit 4 times into the 1mm space.
* When you have messed the first one up, have another go!
* Aim to make the pinhole too small, then widen it using the emery paper. This also reduces the thickness of the metal, so giving a wider angle of view.

5. Fix the pinhole to the mount with black insulation tape, then stick on to the camera back, making sure no light comes in at the corners. (See Photo).
6. Use insulation tape to make a light-tight ‘shutter’ to stick over the hole.
7. Tape over the lens in its ‘open’ position, to enable the camera’s original shutter and wind on mechanism to work without exposing the film.
8. Reverse the film by spooling it into a reusable cassette in total darkness, with the spool upside-down so the emulsion is pointing backwards. Always write the type of film on the cassette.(See Photo)
9. Load the film as normal. How to use the camera. Rest the camera on a surface in front of the object to be photographed. Carefully replace the tape shutter with your finger, making sure no light enters the hole. The exposure starts when you release the camera, and finishes when you place your finger back over the hole before carefully replacing the tape.

Exposure guide:

Sunny = 3 seconds. Cloudy = 10 seconds. Indoors = 10 minutes + Colour negative film gives excellent results owing to its massive exposure latitude. Even gross over­exposure can result in a good quality image.

* Rely on gravity to keep the camera steady, rather than your hands.
* Avoid pointing the camera into the sun or the flashgun.
* Concentrate on the foreground. Objects in a plane receding away from the hole look far more dramatic than objects flat to the film plane.
* Wind on after each photo to avoid double exposures.

Using Flash.

A flashgun in ‘full power’ manual mode can be used to illuminate a subject up to 6” inches away. Two advantages of flash are not having to worry about camera shake, and extreme contrast which adds to the apparent sharpness of the image.

Unloading the film.

After rewinding the film in the camera, wind the exposed film in total darkness back into another reusable cassette, and take to the processing lab with the type of film written on the case.

Collect your final prints, and spend the next hour figuring out just what you have been photographing!

©Justin QuinneII 2002.