Very nicely constructed tele macro zoom from Tamron in Adaptall 2 mount. All metal housing, long and solid, yet somehow I didn't find it burdensome when walking around at length with it mounted on my sturdy Praktica MTL3. Maybe because it's comparatively lighter than the kit of prime lenses it substitutes for. Tele macro means it only works as a macro lens when telescoped out as far as it can go; the lens normally focuses from 6' to infinity whether at 35mm or 135mm, but when at 135mm you can turn past the 6' mark till you reach 1:4 macro (distance unmarked, but approximately 2 feet). Kind of cool but I think 2' is still kind of far away.
Focusing and zooming are very smooth, I like this lens a lot. I just wish it focused closer!
For more info on Adaptall-2 see my Adaptall-2 page. The idea is basically that Tamron made mountless lenses that would accept "Adaptall Custom Mount" fittings that were camera-mount-specific. The adapter becomes functionally part of the lens and works basically as an OEM lens would, with a few caveats.
As with all Adaptall-2 lenses, open up to maximum aperture prior to mounting or unmounting the adapter. Use a wide angle hood, the front element is close to the threads and is fairly flat. While multicoating like Tamron's BBAR (broad Band Anti Reflective) coating is helpful in reducing flare, a hood is still a good idea.
And the other thing I like to mention, because I always forget it myself, is that the length of this lens means your handholding needs to be at higher speeds than for a shorter lens, especially when it's zoomed out. The rule of thumb is to shoot at 1/(focal length) so here it's approximately 1/125. And that goes for the macro as well. Or use a monopod (the toting of which may offset the light weight of your lightened kit now that I think about it!)
- Great overview of the different Adaptall mounts