The M series cameras were noted for their compact size, and are among the smallest 35 mm SLRs ever made, though they are quite heavy when compared to the plastic SLRs of the 1990s. Except for the MX, all were based on the same basic camera body, and featured aperture-priority exposure automation. While superficially resembling the ME, the MX was designed as a manual-only SLR system targeted to the advanced amateur or professional photographer, and had its own set of accessories that were mostly incompatible with the other M series cameras. Conversely, the other M-series cameras were targeted squarely at casual users. None of the M-series, with the exception of the MX, featured a depth of field preview.
The ME featured aperture-priority only automation with no manual override. The MX was entirely manual and resembled the earlier KX in features. The ME Super was an ME with a manual mode. The MG, MV, and MV1 were even simpler versions of the original ME.
The ME-F was an early attempt at an autofocus SLR using a special 35-70mm zoom with a motor built into the lens.