The Opensource Camera Project

Spare parts for analog film cameras are increasingly rare as the current stock is used. People are scavanging parts from used cameras to complete their repair projects. So I decided to reverse engineer cameras as a hobby! This may allow the production of new parts.

The shutter

The first important thing to reverse engineer is the shutter mechanism. This device allows to control the amount of time needed to imprint an image on the film by light. Curtains are blocking the light, then released to open a window from which the light passes through. A few shutters are noteworthy:

• Copal Square S (fully mechanical, methal blades, vertical travel, 8s to 1/1000s & "B").
  Found in these cameras: Konica Autoreflex TC, T1, T2 & T3; Nikon Nikkormat FT.
• Copal Square CCS-M (smaller modernisation of the previous Square S).
  Found in these cameras: Konica Autoreflex T4, TC; Nikon FM.
• Copal Square ES (Electronic).
  Found in these cameras: Nikon Nikkormat EL2.
• Nikon F2 (From 10s to 1/2000s & "B").
• Nikon F4 (From 30s to 1/8000s & "B", derived from Copal).

The light meter

The second thing to consider is the light metering apparatus. Light is measured by means of electronic circuits. Different techniques are used:

• External metering: Light is measured with an external meter. It may be integrated or not (handheld) to the camera body.
• Through the lens (TTL): Light passes through the lens. Light is scattered sideways from the optical path. A tiny photocell is placed accordingly.

Some film cameras have very good light metring:

• Olympus OM-3
• Nikon FA

The wanted cameras (other models may be added)

I bought a few cameras. So I'll begin to work on these in the following order:

1. Pentax Spotmatic (135 format), the venerable ancestor.
2. Praktica LTL3 (135 format), the good east german.
3. Kiev 88 (120 format), the ukrainian Hasselblad.
4. Pentax K1000 (135 format), the sturdy sequel.
5. Konica Autoreflex T3 (135 format), the Copal Square-S user.
6. Kiev 19 (135 format), the soviet 135.