Friday, June 19, 2015
Sears Auto 500 (aka Mamiya 528 TL
While the camera is operated like almost any other auto exposure SLR (except the shutter speed is around the lens) internally the sequence is complicated--the shutter must be open most of the time to focus and frame the picture, with the mirror blocking light from hitting the film. In addition to the steps needed by a normal focal plane shutter, the shutter must close, wait for the mirror, open for the exposure, close, wait for the mirror again, then open. All this with springs, cams and levers rather than electronics. The aperture has only 2 blades, the lens isn't very fast for the focal length, and it is only a 3 element front focusing lens. As far as I can tell, the main purpose for all this is essentially the status of an SLR, with the ease of automatic exposure on a budget--it lets its owner claim SLR status. I believe the price in 1968 was $89, extremely low for an auto exposure SLR. At the time metered manual true SLRs were typically twice that for budget models--Minolta's base model SRT 100 was around $175 and was metered manual rather than auto exposure.
This one appears to work fairly well, although I have not tested it with film. Shutter speeds appear accurate, the meter responds to light and the aperture changes as it should. The only problem I can find is that the stop on the lens is missing, so it does not stop at infinity, and without the stopit is possible to unscrew the front element entirely.