I have seen quite a few posts regarding the 135mm Rokinon f/2.8 as a portrait lens for full frame cameras. Most of these postings praise the Rokinon for its low price and very decent I/Q.
However here is the least expensive lens that I own... It is a Sears Auto 135mm f/2.8 (made by Tokina I believe) which comes in an M-42 mount and can be adapted with a very inexpensive "dumb" adapter...
I purchased this lens for $11.00 dollars plus a few bucks shipping from the Goodwill Auction site. Not bad quality for a bit over eleven bucks




