October 2018’s OSCC meeting kicked off our current project – Pinhole Photography. Here is a summary of what was discussed and ideas shared which will hopefully motivate you to join us in November.
The Pinhole Camera
When asked to describe a camera, one is likely to list the obvious conventional parts: lens, shutter, etc. In fact the lens is arguably the most defining feature of a camera – and not essential to take a photo. I’d personally argue that a camera is any instrument that can record a photograph.
If anyone has had the luxury of visiting a camera obscura, than you’ve been inside a magic of a camera. Plymouth Hoe was home to a camera obscura apparently where the ‘Wedding Cake’ is now situated. These were strangely popular Victorian tourist attractions, where you would pay to see the view outside, projected on the wall of a otherwise dark room.
A pinhole camera is the exact same mechanism as a camera obscura. A pinhole camera is a camera with no lens, a small pinhole does the same job of squeezing light into a projection on film/photographic paper. The small aperture of a pinhole allows an infinite depth of field, similar to how you can blurry vision can be temporarily solved by squinting your eyes.
Pinholes only require:
• A light proof container.
• A pinhole.
• Photosensitive material (film/photographic paper).
A box with a hole with photographic paper inserted into it can record a photograph.
Paper/film must be loaded in the dark (B&W paper can be loaded under a safelight). The box must be light tight and non-transparent, this can be solved with masking tape and black paint. The pinhole must be covered until you wish to take your photograph. The smaller the hole, the more sharp the image. Also try to make a clean hole, and consider sanding/smoothing the puncture for better results.
The ‘box’ can be anything light-tight, a shoe box, food can, a human skull (this exists), a camera with its lens replaced with card with a pinhole! Be experimental!
Pinhole photography is the simplest form of photography, and possible the best way to really understand how light is used to create a photograph. Perhaps for some, in the shamelessly Luddite fashion of the OSCC, its about freedom. The principle that all you need to capture a photo is a light proof container and light sensitive material also means that you have complete control over how the camera operates and the style of photograph it creates. I can’t take a multiple exposures of my rangefinder, it has a motor that has not been designed to allow it. I can’t take a long exposure on my point and shoot. You must have experienced similar frustrations.
Along with having no lens distortion and infinite depth of field (the f/64 club had the wrong idea!), pinholes are popular for creating extremely long exposures which can be impossible to achieve with conventional f-stops. Holly showed us her photograph she had made form her ‘Solar Can’ - a pinhole in a soda can exposed for the whole of October! The fantastic photo shows the beautiful paths of the sun across the sky, slowly changing with each sunrise-sunset.
Here are some examples of different examples of techniques you can consider when thinking about what sort of pinhole camera you would like to construct:
• Long Exposure
Made easy with such a small aperture! Right? Remember reciprocity failure!
• Multiple Exposure
You have the freedom to exposure the same bit of paper/film in your pinhole however many times you you like! Best to learn how to exposure multiple exposure by doing them but a good rule of thumb to start with is to divide the exposure time by how many photos you plan on taking (i.e. two exposures would each have half the metered exposure time, making the total exposure ‘correct’).
• Multiple Pinholes
Having multiple light sources are also possible! Consider whether you would like your two pinhole images to overlap each other or not. Make many holes for the ‘bug eye’ style.
• Conventional Film
Shoot with your favourite film brand if you are using a conventional camera with a pinhole modification or you have constructed a way to load roll film.
Ilford FP4, 10”x8
• Curved Film Plane
Make your image wide angle (in one axis) and correct for vignetting in one go!
Paper/film placed on a curved surface of a cylindrical container (e.g soda can, Pringle pot), will give this effect.
• Any format you want
In theory you can make your camera to any size you like, and cut your film/paper in such fashion. Perhaps the easiest and cheapest way to try panoramic, square or large formats.
• Combination of Above!
Bonus points if you pull them all off in one photo!
The following formulas allow you to estimate you aperture needed for metering along with focal length and other useful information. Don’t be put off by the maths, the only thing you need to know is the diameter of your pinhole and the thickness of the material the pinhole is through. The rest is done by a calculator. This is not essential, and trail by error can be a valuable experience!
...where d is Pinhole Diameter and t is Pinhole Thickness in mm.
This should be all you need if you plan on getting light meter readings to calculate the correct exposure. Bear in mind that meters are unlikely to go up to the high F numbers of a pinhole.
So whether you feel like ditching your lens off SLR, directing light through a cola can or putting 35mm film through a matchbox, I look forward to seeing you inventions and the photos we create using them! Next meeting with be at the OPM Suite at Plymouth College on Monday 26th November I hope to see you there! Don’t worry if you have not had time this month, just bring some ideas and possible materials for a pinhole.
Will Jay Nov ‘18
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