Olympus G.Zuiko Auto-W 25mm f/2.8

  • Weight: 160 grams
  • Filter Thread: 43mm
  • Closest Focusing Distance: 25 cm
  • Maximum Aperture: f/2.8
  • Aperture Range: f/2.8 to f/16
  • Optical Design: 7 elements in 5 groups
  • Angle of View: 62°
f/8

Released in 1966, the 25mm f/2.8 filled a critical gap in the Pen F system’s wide-angle lineup. Existing lenses included fast normal and telephoto primes, such as the 40mm f/1.4, 42mm f/1.2, 60mm f/1.5, and 70mm f/2. Wide-angle options were limited to the slower 25mm f/4 and 20mm f/3.5.

f/2.8

The bokeh is smooth and uniform for a wide-angle lens, with gentle transitions between in-focus and out-of-focus areas. 

f/2.8
f/2.8

In this case, the strong vignetting in the far corners is caused by a lens hood, not the lens itself.

f/4
f/8
f/8

Sharpness peaks at f/8. This lens is susceptible to flare and ghosting due to its older coatings, though it performs better in this regard than the 20mm f/3.5.

f/8
Camera 35, Jan 1970

Additional Pen-F Resources:

Christopher J. Osborne’s in depth archive of Pen F literature and system overview.