Bah! Humbug! to the London Marathon. Much more interestingly today is World Pinhole Photography Day – always the last Sunday in April.

Before we had lenses for cameras, and indeed before we had photographic film, it was possible to view a scene, and project it onto a wall, using a tiny aperture. This was the camera obscura used by artists since ancient times.

Once cameras and the photographic process were available, it became possible to do this trick with a tiny pinhole instead of a lens. Needless to say the results are not sharp, as they would be with a lens, and because of the tiny aperture exposure times are much longer than we’re used to these days. But the smaller the pinhole, the sharper the image and the longer the exposure needed.

Nevertheless it is a fun, and often instructive, technique to try – and these days it’s very easy with (digital) SLR cameras. All one needs is a pinhole – and you can make that yourself! (If you hunt online there are people who will make a pinhole for your camera; or even sell you a bespoke pinhole camera.)

There are a number of “how to” sites on the internet. Basically you need only a spare camera body cap and bits and pieces you will already have lying around, like an empty drinks can.

A couple of years ago I made a pinhole for my Canon dSLR following the instructions on wikiHow. It was a bit tricky for me, with my ten left thumbs, but after three or four attempts at making the actual pinhole (in a piece of drinks can) I made something which works adequately if not brilliantly.

Setting up and taking pictures is easy enough. Fit the pinhole (body cap) to the camera and mount the camera on a tripod.
Set the camera to manual and ISO 100 (or slower). You can’t adjust the aperture of the pinhole, which will be tiny, so you then have to experiment with exposure times of 10-30 seconds (compared with the normal 1/100th or faster) in good light; longer in poor light or night. Use a remote control (or the camera’s timer delay). Now experiment.

So today I found my pinhole, and had a wander round the garden to see what looked likely to make a decent photograph. The images here are the best results (slightly colour enhanced). For comparison the following final two images are of the garden with a pinhole and with a normal lens on the camera – I reckon for a piece of crude homemade old technology the pinhole doesn’t do a bad job.

Of those four pinhole images, I think the first, the dandelion, has worked the best. What does anyone else think?