Originally posted by Darkover The old Pentax 135/2.8 is one of my favorite lens for this reason. And it is surprisingly cheap and easy to find. But stay away from the 135/3.5. bokeh and sharpness is less good compared to the 2.8. I think the 135/2.8 is on the same level than the 85/1.8 and this neither cheap nor easy to find.
Which 2.8/135mm?
Of all the Pentax 135mm lenses with PK bayonet I tried a few.
In the old times I had the M 3.5/135mm (small and better than average), the Takumar Bayonet 2.5/135mm (didn't like it very much, I sold it after a short time).
Now I have the A 2.8/135mm and the K 2.5/135mm. I like the latter more than the former, even if it fringes and is not super sharp wide open.
I believe the F and FA versions of the newer 2.8/135mm design to be better than all the previous lenses of the same focal.
Unfortunately I never had the chance to try one.
cheers
Paolo