Olympus's f/1.2 PRO normal prime — same as OM System ID 1731, original Olympus branding.
The Olympus M.Zuiko Digital ED 25mm f/1.2 PRO is a fast standard prime from Olympus's M.Zuiko PRO line for Micro Four Thirds, released approximately 2016. 25mm on MFT gives a 50mm equivalent field of view — the classic standard focal length. Among the fastest available primes in the MFT system. Micro Four Thirds mount.
f/1.2 maximum aperture. 25mm focal length (50mm equivalent on MFT 2× crop). 9 elements in 7 groups. PRO-grade weather sealing and metal construction. At approximately 300g. 62mm filter thread. Micro Four Thirds mount.
The PRO designation indicates Olympus's top-tier M.Zuiko standard: weather sealing, metal mount, and optimised optical formula. f/1.2 is the fastest aperture class in MFT primes; the 2× crop factor means depth-of-field equivalent is approximately f/2.4 on full-frame. The 50mm equivalent is the classic street and portrait focal length. Compatible with all MFT bodies including OM System.
On the used market the Olympus M.Zuiko Digital ED 25mm f/1.2 PRO is a premium fast standard prime for Micro Four Thirds cameras. Condition checks: 62mm front element for marks, AF response on Olympus and OM System MFT bodies, weather-sealed barrel for damage. MFT mount — compatible with all MFT bodies.