It uses match needle method for exposure metering display. The metered prism used is DP-11 and sensors used are Cds. Generally considered by collector and Nikon fans as the best representation of the prime time of mechanical engineering in camera design during the '70 era. With an AI version of the EE aperture Control device, the DS-12, shutter priority automation is possible. Metering was center-weighted type by a pair of silicon photo diode sensors, full scale 5 point LED readout system.
Unmanned photography is possible by intervalometer.
A Fully featured website for Nikon FM has been uploaded. This is the first compact SLR manufactured by Nikon. It was to replace the more bulkier FT series. It is an all mechanical body. The FM uses a gallium photo diodes to handle its metering.