I recently purchased an M. Zuiko 17mm f1.2 lens after reading it’s the sharpest lens in the micro four thirds system. I have the 25mm f1.2, and it’s been wonderful – even wide open – but all the technical lens tests say it is a step below the 17mm f1.2 and the 45mm f1.2 in terms of sharpness.
Ive been testing this new 17mm lens and I immediately noticed it is almost unusably sharp wide open – not something I’m used to since I can use the 25mm wide open and achieve very good sharpness. The 17mm wide open leaves quite a bit more to be desired, which is not what I expected based on the reviews online.
Stopping down to 2.0 the 17mm does get very sharp and far more useable, but I’m a bit disappointed by its performance wide open so far.
Maybe someone can take a look at these test shots of a wall, tell me if theyre worth anything at all in terms of being able to tell why this is happening (ie, maybe it could be due to the focal length being wider, or the field curvature being more curved or something? I was thinking, maybe it’s that with closeups at 17mm the DOF is so shallow that there isn’t much there to be in focus l, but I don’t think that’s it)
((Also I’m not asking whether either of these shots are usable, really only using them to compare the sharpness wide open of these two lenses))
Feeling like maybe I should just return the 17mm and use the 12-40 f2.8 I have on the shelf if I ever need to go wider than 25mm.
[First pic is 17mm, second is 25mm, distance from wall is ~1m]


Those two pictures are identical in every way except the lens?! That’s pretty astonishing. The difference is stark.
Yeah, no settings changes camera-side. Just swapped the lenses and kept em wide open. Both are straight out of camera.
Edit: You gave me the idea to just take a quick look at the RAW files, just in case it is something with the camera post-processing. The 25mm RAW is definitely sharper than the 17mm, so its definitely a lens thing
Yeah definitely look at the RAWs. I should also have asked what model camera it is.
It’s an olympus OM-1 mk ii
(thanks for taking a look btw)
Sure. It would be nice if this community got more posts and comments!
I took a look at the interior of the lens by shining my phone light through the back of the lens toward the front, and I saw quite a bit of …erhm… smearing? on the front element of the lens. I’m thinking it may just be a bad copy. Initiated a return


