This compact little camera was, apparently, a marketing miracle in its day selling around 10 million (i.e. 10,000,000) units over several years. Essentially, it was/is a fully automatic point and shoot (except for the need to -at least- "zone" focus). It is "powered" by a large Selenium cell which surrounds the lens inside the filter-ring, resulting effectively in a "kind of" TTL "equivalent" metering. This also "powers" whatever it is that sets the aperture (2.8 to 22) and shutter speed (choice of either 1/40th or 1/200th sec). Consequently, there are no batteries: great! There is also a "hot shoe" for a simple one-pin flash (this works OK). When using the camera, one can observe that it selects and holds the aperture and shutter speed (i.e the exposure) as one depresses the shutter release prior to releasing the shutter itself: thus it has -effectively- an "exposure lock". The camera is relatively compact and well constructed of aluminium and glass with a few plastic components (not virtually totally plastic, as is the case these days) and has a nice "solid" feel to it. The 43mm lens is noticeably sharp (zone focusing and all). Ken Rockwell, on his site, compares it more than advantageously to his Canon "L" lenses in resolution (http//www.kenrockwell.com/olympus/trip-35.htm , worth a read). This is all the more surprising, since the iris consists of only two V-shaped blades which move across each other to vary the size of the aperture. One would imagine that such a "primitive" iris would give an odd image: not so, the image is absolutely superb (my opinion, shared by Ken Rockwell). I was fortunate, some weeks ago, to find three of these cameras for sale (at Aus$8-00 each) in a "junk" shop and picked out the two that were in working order (one of which included a lens-shade and both came with UV/skylight filters and -somewhat tatty, but functional- cloth "cases"). I have since put a couple of 400 ISO films through each of them with more than satisfactory results. They are extremely easy to use and -in my opinion- would make excellent "street shooting" and general "have one with you at all times" cameras. If you see one, get it! So many cameras, so little time!!!!!