Christopher J Osborne

G.Zuiko Auto-W 25mm f/2.8


Olympus Pen F G.Zuiko Auto-W 25mm f/2.8 mounted on an Olympus Pen FT

Olympus Pen F G.Zuiko Auto-W 25mm f/2.8 mounted on a Sony A7 MkII

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

Cropping needed? Yes
Average 35mm equivalent focal length after cropping: 29mm


25mm f/4 image 1 - OOC+EC



25mm f/4 image 1 - Cropped
Image size: 17.9mp
35mm equivalent focal length: 29mm

25mm f/4 image 1 - Final
Image size: 17.9mp
35mm equivalent focal length: 29mm

25mm f/4 image 2 - OOC+EC



25mm f/4 image 2 - Cropped
Image size: 18.5mp
35mm equivalent focal length: 28mm

25mm f/4 image 2 - Final
Image size: 19.1mp
35mm equivalent focal length: 29mm

25mm f/4 image 3 - OOC+EC



25mm f/4 image 3 - Cropped
Image size: 17.9mp
35mm equivalent focal length: 29mm

25mm f/4 image 3 - Final
Image size: 17.9mp
35mm equivalent focal length: 29mm

25mm f/4 image 4 - OOC+EC



25mm f/4 image 4 - Cropped
Image size: 17.9mp
35mm equivalent focal length: 29mm

25mm f/4 image 4 - Final
Image size: 17.9mp
35mm equivalent focal length: 29mm

The 25mm f/2.8 is the big brother to the f4 version. It is physically much bigger and has 7 element design rather than the 5 element design of the f/4 version. On the half-frame cameras it was designed for it has a 35mm equivalent focal length of 35mm. Today it is much rarer and difficult to find. Unfortunately mine doesn't work properly. It has always had a slightly dysfunctional focus ring, but it has recently stopped focusing on anything further away than about 1m, which is why you will only see close-up photographs above.

As you can see from the OOC+EC images this has a somewhat smaller imaging circle than the 25mm f/4 and always needs cropping to an effective focal length of around 28 or 29mm. But it is capable of very nice results. O hope to get this lens repaired at some point, at which time I will update this page with a more representative set of photographs at all focus distances.