Model Description
Zenit 18 is a follow-on of Zenit 19, using mostly the same SLR body, but with omitting the DOF preview button, and transferring the activation of the light meter from it to the shutter release. This camera also offers aperture priority automatic exposure, a significant first for Zenit M42-mount cameras. Even more significantly the camera has a support for full aperture metering with special M42 lenses equipped with proper electronics and electric contacts.
Other differences to 19 are faster flash sync speed, being 1/125 instead of the slower 1/90 of the 19, and added requirement of batteries, requiring four batteries instead of two used by 19, the increased power requirements probably caused by the more complex electronics. The film speed setting dial has also been moved from the bottom of the camera to the top, the dial being around the film rewind wheel. Top shutter speed is 1/1000 on both cameras.
Both Zenit 19 and 18 use PX625-type batteries, which are hard to get in the original mercury form nowadays, but fortunately both cameras use a bridge-type metering circuit, and thus alkaline or silver oxide type 625-size batteries can be used without any loss of metering accuracy, and without need for exposure meter recalibration.
Unfortunately the electronics are unique to this camera model only, and apparently only one dedicated lens allowing full aperture exposure metering was designed and manufactured in small numbers, Zenitar EM 50/1.7, which also has an odd square aperture formed from only two L-shaped parts. The automatic exposure system of course works with all M42 lenses, but requires stop-down metering to be used when using other than the dedicated lens.
The dedicated lens is even rarer than the camera itself, and the camera isn't very common either, with only 7001 examples being made it does rank among rarer models in the line of normal production Zenit cameras. The model was manufactured between 1980 and 1987.
Experiences on using the camera
There are several slightly odd features to the operation of the camera, especially that changing shutter speed requires lifting the dial before it can be turned to another position, but the film speed selection dial can be rotated without lifting, which does make changing shutter speeds slightly tedious (apparently the designers thought that the automatic exposure would mostly be used), and changing film speed by accident somewhat easier.
The shutter speed dial is also slightly small to be easy to use, especially with having to be lifted before turning. Activating the light meter is also a bit tricky, requiring the shutter release to be pressed quite hard, nearly hard enough to trip the shutter, at least on my example. Also releasing the shutter button does immediately cut power from the electronics, or so it seems, as longer exposure times require shutter release to be held down for all of the exposure, which is otherwise cut short.
The viewfinder does offer enough brightness to be well usable in normal lighting conditions, but the exposure meter isn't very easy to see, having black markings, and only displaying overexposure, underexposure and shutter speed of 1 s, 1/30 s and 1/1000 s on the scale, thus giving only an approximate idea of the correct shutter speed. This shortcoming is made worse by the scale lacking a match needle, making deciding exact choice of shutter speed somewhat harder when using manual exposure, another indication of that it was probably originally thought that mostly the aperture priority mode would be used. My example has a split-image focusing aid in addition to the microprism area, but it seems that generally most examples have only the microprism area and the split-image equipped version is considered to be rarer, possibly even an after-market modification.
Generally the camera body is well built, and does have a solid feel, is tolerably easy to use once gotten used to and the auto exposure does also give at least usable results in most conditions, apparently being of center-weighted type. Both an usable, well built M42 camera with some interesting features, and a quite rare, historical piece of Soviet camera development.