Contax IIa

Contax IIa was introduced in early May, 1950. The design was a work of genius. Its rangefinder inspired Nikon designers to implement it into their rangefinder models.Its vertical running focal plane shutter, and its thumb driven focusing wheel were copied in every detail by Russian Kiev. Contax has a complex shutter if you ever decide to work on. Instead of the high speed self capping curtains, this camera runs a metallic, garage door like curtain that runs much slower, and it seems to be slowed down by a escapement throughout its travel.

Contax IIa with 85 mm f/4 lens

Contax IIa disassembled to show its rangefinder, and shutter

From my book: "Restoring the SLR".

Both Nikon, and Contax had to have two mechanical links between the body, and the lens. The outer coupling was the bayonet mount. The inner coupling engaged with the rangefinder mechanism to rotate with the finger operated focusing dial next to the release button.

Contax IIa Shutter (left) is the only focal plane shutter in a camera that the first, and second curtain take up rollers are combined into a single but complex roller (bottom). The slit forming gears on top adjust the slit width as shown. This illustration also shows the shutter winding operation where both the first, and second curtains are wound by the charge gear on the right.

Winding

Gear

Curtain tension Adjustment gear

2nd Curtain

Not an easy Repair !

Drawing by Ali Afshari, From the book: "Restoring the SLR".