We were planning a trip that would be ideal for the Q - more precisely the Q and an 06 telephoto lens. I bought one at a good price and liked it a lot, but then the trip was called off. While looking for ways to economize on the larger kit I encountered a trade offer of a Tamron 90 f/2.5 for an 06 zoom. The deal was made, and now the 90mm macro has arrived!
model 52E) was unknown to me, I read up on it before making the trade offer. Until now I thought that all f/2.5 models were manual focus, so this must be their first AF model. I also thought all Tamron 90s were 1:1 macros but this one is 1:2. So much for my general knowledge of early Tamron macros! :^) It also lacks the bizarre AF/MF clutch that both Sigma and Tamron think are so clever, which may be true with non-Pentax systems. That alone makes this appeal to me, as I really dislike the two-step focus change!
So this lens has AF, aperture ring and a limiter switch, and takes 52mm filters. With the limiter set the lens snaps into focus down to about 1:4 which isn't a bad place to change over. And it really does snap; focus speed is very fast even with no limit set - but it definitely helps to stop the spinning if it isn't needed. The image quality is extremely good even wide open so it can be used as a general low-light lens and not merely for good closeups. And if I feel really bold it can be a 180mm f/5 supermacro with the Vivitar macro/TC attached, though I haven't tried this to say how the results might look.
This serendipitous find allows the 85mm f/2 to find a new home, which will pay off a few items on the lens account. Like the SMC 17mm before it, I find myself forsaking all-manual lenses for AF/auto-aperture and saving some money in the process. This along with the F17-28 and DA20-40 are very good lenses so whatever happens I'll be just fine.