The Olympus OM system was released by Olympus in 1972. The Olympus OM bodies were divided in a high range and a middle range. The top range were the one digit models with a hyphen: OM-1/2/3/4. The two digit models were the middle range. All these bodies could take Olympus OM lenses (which means all potentially have DOF preview functionality, as this was standard on most OM Lenses).
Following the introduction of autofocus into the market, Olympus released two motor-driven bodies: the OM707 and the OM101. Later yet, a re-branded Cosina model was released, known as the OM2000.The OM10 was the first consumer OM series body. Launched in 1979.
it accepted the full line of OM lenses and most of the OM accessories for a lower price. The lower price was reflected in the construction of this camera and the features available, however, it was still a very competent performer and it reflected the elegant lines established by the compact OM-1 and 2 designs. Early production runs of the OM10 have known malfunction issues with electronics, metering, and shutter magnets.source needed Olympus later changed the shutter to a 'Type II' design to correct the latter problem.source needed
In its standard configuration the OM10 offered aperture priority automatic exposure, simple and accurate enough for a consumer camera in most lighting situations. It also offered exposure compensation for more complicated lighting situations and for more advanced users. Selection dial upon the top allowed for selection of Aperture Priority, B and Manual adapter, The small plug-in manual adaptor was available as an accessory to enable manual control of shutter speed, if no Manual Adapter was plugged in and the camera switch set to Manual Adapter then the camera shutter speed was set to fixed 1/60 for flash work.
While not well known to consumers, the focusing screen for the OM10 is indeed interchangeable, though not as easily as the OM-1. It shares the same focusing screen as the OM-1, but the extra protruding tab needs to be cut off as the OM10 doesn't have a placeholder for it.