Originally posted by tim60 Can I add a question - would getting a 120/2.8 provide something usefully different than these three offer?
A slightly shorter minimum focus distance than the 135s - 1.2m vs. 1.5m. It is still 49mm and lighter than the 135/2.5. The Takumar and K versions have 6 blades, while the latest Takumar version of the 135/2.5 and the K have 8.
The 120mm is rare enough that I decided to just buy it and see for myself, since most people haven't tried one. I ended up with the M version, which I like a lot. Physically it is like the M135/3.5, 8 blades, a hood, but just a bit better in everything. I like the focal length on APS-C. A set of shots is here:
Single in August 2013 - a set on Flickr