Classic Project: Pinhole camera
Image credit: Dreamstime
If you ever wanted proof that the fundamentals of technology don’t change, look no further than the pinhole camera.
Although capturing images on light-sensitive media has only been around since the 1820s, the optical ‘camera obscura’ effect has been known since the Ancient Greeks, when Aristotle and Euclid wrote on naturally-occurring rudimentary pinhole effects, such as light travelling through leaves in trees creating unusual effects.
The earliest description of this kind of observation dates from the 5th century BC, by Chinese philosopher Mo Ti. The first manmade machine for projecting images was built by the Arabian physicist Ibn al-Haytham (known in the west as Alhazen) from the town of Basra (now in Iraq) in the 10th century. In his book on optics, Alhazen says of his innovation “Et nos non inventimus ita” (“we didn’t invent this”), presumably alluding to the fact that it was a natural effect, as already noted by Aristotle.
The idea of using the principle to create permanent photographs came into being in the mid-1880s when British physicist Sir David Brewster is believed to have taken the first photograph with a pinhole camera (though there is evidence to suggest that other scientists were working on the same thing at the same time).
The technique became more established during the late 19th century, but was soon to be overtaken by lens-based technologies capable of generating much sharper images. As a consequence, the pinhole camera was virtually forgotten until the end of the 1960s when it became a staple of experimental art.
The pinhole camera can be as simple as a lightproof box with a tiny hole instead of a lens (which means that pinholes fit into the modern category of ‘lensless photography’). Although there are commercially produced models available (notably by Zero Image), the process is the same if you construct one for yourself from a shoebox. As light passes through the aperture from the outside of the enclosure, an inverted image is projected on the opposite interior wall by the process of rectilinear propagation. The bigger the hole, the less sharp your image will be, but it will also take less time to expose your image. Place light-sensitive paper or film on that wall, and you have your photograph.
The process is deceptively straightforward. However, as anyone who has ever made pinhole images will confirm, it can be frustratingly hit-and-miss, unless the photographer has a detailed knowledge of the mathematics involved with calculating exposure times (there is now plenty of software to help with this). Yet, in theory, there are no compelling reasons why a pinhole can’t deliver satisfactory results, although perhaps not quite on a par with those from digital cameras that have electronically timed shutters, settable apertures, focusable lenses and high megapixel-count sensors.
Although the invention of the modern lens-based photographic camera eclipsed the pinhole and relegated it to either a novelty or classroom experiment, pinhole technology has enjoyed a huge surge in popularity in the 21st century as a ‘lo-fi’ counter-statement to the ever-increasing complexity and automation of digital cameras.
With professional-level 35mm-equivalent DSLR cameras costing anything up to £5,000 (medium format variants such as the Phase One XF system come in at over £30,000), photographers are increasingly looking at ways of recording the world around them with cameras that can be made from empty beer cans or even cracker biscuits, the latter of which has the advantage of being supplied with several pinholes already in place.
Facts and figures: Pinhole cameras
A genuine pinhole camera has no lens. A camera with a lens cannot be classed as a pinhole.
Pinhole cameras can be made out of paper. Paper cameras were popular in Communist Czechoslovakia in the 1970s.
An alternative name for the pinhole is ‘camera obscura’, Latin for ‘dark room’.
There are several smartphone apps that replicate the pinhole effect.
The earliest use of the term ‘pin-hole’ is found in James Ferguson’s 1764 book ‘Lectures on select subjects in mechanics, hydrostatics, pneumatics, and optics’.
Modern photographers using pinhole cameras include Steve Gosling, Steven Pippin and Nick Livesey.
World Pinhole Day is an annual event held on the last Sunday in April.
A pinhole camera doesn’t focus, but acts as a ‘centre of projection’.
Date: 1890s (first commercial pinhole cameras).
Originator: Sir David Brewster (first to take pinhole photos).
Unit cost: Today commercial models start at around £50
General arrangement based on contemporary ‘Zero Image’ design
Film supply and take-up spools
Manual spool knobs (brass)
Bull’s-eye spirit level
Shutter release cable thread socket
Film plane (film formats include 35mm roll film, 120 roll film medium format, 4 x 5 format and 8 x 10 format, depending on model)
Front panel with pinhole (obscured by shutter – pinhole surrounded by 0.001in brass shim)
Body (material = teak)
(Inset fig) How light and a pinhole form an image