The Praktica MTL 3 is an East German SLR made by Pentacon, using the 42mm screw mount. It was produced in high numbers between 1978 and 1984. It is said to be based on the LTL 3. It's a solidly made camera with some rather crude and some advanced features.
The shutter
This is the best part about this camera. The MTL 3 has a metal curtain shutter. It moves vertically and is likely to work some 25 years after its production. Speeds are B, then from 1 to 1/1000 sec. It has a separate position for use with electronic flash units; this is "about" 1/125 sec according to the camera's manual. Its metal curtains are not known to get punctured easily as do cloth shutters.
Metering and Viewfinder
The MTL 3 has a metering system that is integrated in the mirror. This makes it important to handle the mirror with care, or rather, never to touch it at all. A needle on the right side of the viewfinder indicates the correct exposure; o is correct, + means overexposed, - underexposed. This metering system is the only battery-dependent system in the MTL 3. It takes a single 1.35v PX 625 mercury cell; without it, everything but the meter will continue to function. A switch next to the shutter release button stops down the lens and switches on the meter. This way, no battery power is wasted when the camera is not in use.
A black wedge on the left indicates the film has not yet been transported.