Purma, a Special Camera
The Unique, Gravity-Activated Purma Plus and Purma Special 127 Film Cameras
6 min read by Justino Lourenço.Published on . Updated on .
This article is about Purma Plus and Purma Special 127 film cameras — the models I have the privilege to own. In a sentence, I would describe these cameras as a charming blend of design and innovation.
A brief history of Purma, its founders, and their focal-plane shutters.
One of the people who created those cameras, Tom Purvis, was a well-known British painter and poster artist of the early 1900s. Together with Alfred C. Mayo, they found Purma Cameras Ltd. in 1935. Their business name originates from the founders’ surnames, Purvis and Mayo combined into a portmanteau: Purma. Same as Leica, made up of Leitz and camera.
Throughout their existence, Purma filed for fifteen patents (according to Google Patents), four of which were for a focal-plane shutter. The company used their innovations to create and market three camera models:
Purma Speed (1936) — made with enamelled metal body, Purma Special (1937) — an all Bakelite body*, and Purma Plus (1951) — with an aluminum body.
✱ — Bakelite is a brittle, hard plastic popular between the 1930s and 1960s. You can recognize it by its colour (usually black) and shiny appearance. Another example of Bakelite in use is Voigtlander Kontur finder.
As I researched resources for this article, I found the patents for these cameras rather fascinating, particularly the one for focal-plane shutter mechanism:
About Purma Special.
The production of the Purma Special camera began in 1937, stretching all the way until 1951 — a remarkable fourteen years on the shelves!
The Bakelite camera uses 127 roll film to make 32 ✕ 32 mm square exposures. It weighs 340g and measures 15.3 ✕ 5.7 ✕ 7 cm. Its only setting, shutter speed, is cleverly controlled via gravity and the camera’s orientation. There are three shutter speeds on Purma Special cameras: “fast” (1/500s), “medium” (1/150s), and “slow” (1/25s).
Purma Special has no double-exposure prevention mechanism. Its 𝒇6.3 57mm lens is collapsable — held in retracted position with a screw-on lens cap. Its focus depth of field extends from 3m to infinity. Close-up and colour filters were available — but are now very rare.
Because it is a square format camera, the orientation has no impact on the image composition with Purma Special.
Purma’s focal-plane shutter actuates closely to the film surface, sending light in through a slit. A clever mechanism controlled the slit size and the shutter speed via weighted lever. The lever accelerated the shutter’s speed when it fell down with the gravity in the upright position (the “fast” camera orientation). The lever had no effect on shutter speed in the position when it lied on its side (the “medium speed” position). The elver slowed the shutter down when it acted as a counterweight in the upside-down position — “slow speed.”
About Purma Plus.
On the face of it, Purmpa Plus isn’t much different from Purma Special, aside from its alluminum-made body.
Purma Plus has a 𝒇6.3 57mm collapsable lens with the help of the screw-on lens cap. This lens’ depth of focus, however exptends from 3.66m to infinity. The shutter is essentially the same — gravity/orientation-controlled with double-exposure prevention lock.
The veiwfinder on Purma Plus comes with two upgrades over Purma Special: the speeds are now clearly marked around the window and the view is blinded when the camera needs winding (to help avoid taking “blank photos”).
A few photos, taken with Purma Special.
Some of these images are also a part of my Autumn Essay.
References.
I used the following resources to come up with this article:
Coe, Brian, Cameras, From Daguerreotypes to Instant Pictures, pp.129-132, Marshall Cavendish Editions, London, 1978;.
Christies, The British Camera 1840-1960 - The Jim Barron collection, South Kensington 2002;.
Purma cameras on Camera-Wiki.
Purma cameras on Camerapedia.
Purma Special on the Living Image Museum.
Purma Cameras on David Gardner’s Great British Cameras site.
1935 and 1936 patent at Google patent search.
Mike Eckman site.
Purma Special manual on cameramanuals.org.
Purma Plus manual in cameramanuals.org.
Camera manuals and images on cameramanuals.org.
Purma Camera Ltd Patents and company info on goodip.io.
Google patens of Purma Camera Ltd on Google Patents.