The viewfinder-only M of 1959 — an M2 without the rangefinder, made for scientific use.
The Leica M1 was introduced in 1959 as a simplified variant of the M2, sold without a rangefinder for scientific, technical and copy-stand work where focusing was handled by a Visoflex reflex housing or by scale. Leitz built roughly 9,400 units in Wetzlar before the model was replaced by the MD in 1964.
The M1 is a 35mm film body with the Leica M bayonet and a horizontal cloth focal-plane shutter running from 1 second to 1/1000 plus B. The bright-line viewfinder shows 35mm and 50mm frames simultaneously with automatic parallax correction. There is no rangefinder patch and no light meter. Film advance is by single-stroke lever, rewind by knob, and the body weighs about 560g.
What separates the M1 from the M2 and M3 is the absence of the coupled rangefinder: both frame lines are visible at once and focusing relies on scale marks, depth of field or a Visoflex. Its short production run makes it far scarcer than the M2, and many surviving bodies show laboratory or institutional use.
Check the shutter curtains for pinholes, confirm the slow speeds run true and look for haze in the viewfinder. Serial numbers fall between roughly 924569 and 1102900; some bodies were later converted with rangefinders or motor drives, which affects originality. Budget for a routine service on unserviced examples.