I got this lens again (after briefly owning one last year - I bought that copy as a present for a friend but couldn't resist the temptation to try it in the field). I'm using it, as before, on a Canon 1D Mark 4 camera. The reason I bought it is that I needed a telephoto lens to replace my 70-200/2.8L IS that has gone into servicing (and god only knows when they're done with it). And since I wanted a lighter - but good - telephoto anyway, I decided that I could just get it and be done with G.A.S. for some time.
My observations between this copy and the last year's one (I need to ask how it's doing) are as follows:
- The lens is sharp, including at 200mm+ and f/5.6, but not what I'd call pin/razor sharp - it's clearly doing well for my intended usage of it but probably wouldn't win any prizes. The 16-35/4L IS I'm using alongside the Tamron is noticeably better. Well, this was your Captain Obvious again.
- The focusing isn't very fast - probably because the focus throw is rather long and there's no focus limiter - but it does the job.
(note: a great deal of these reservations probably stems from the fact that I'm using the lens a lot in dimly lit venues, where stopping down a lot is not possible. Such is my line of work).
- During last year's trial I was irritated by the rings that rotate the "Nikon" way. This time around, I couldn't care less.
- Last year's copy had rather stiff/uneven zooming; this one I have now is a lot smoother. That, or I just got used to it.
- Again, last year's copy had what I construed as a noisy IS. Now, I can say that while the stabilizer action is readily audible, I'm not finding it objectionable anymore. However, the IS sometimes noticeably "jerks" into action, reminding me of the worse experiences with the Canon 17-55/2.8 IS, but without any problems with blurred images or something. I can add that shooting at 300mm requires a more controlled technique than the one I'm used to after years and years of using the 70-200/2.8L IS.
- The build quality is meh:
First, the switches are small and flimsy, easy to knock into an undesirable position. Two pieces of insulation tape have solved this issue, however.
Second, when mounting/unmounting the hood, I always have a feeling that I'm about to wring the front barrel out of its indended place.
Third, I recant my earlier statements about this lens having no zoom creep: creep it does, so when Tamron gets around to making the mk.II of this lens, I hope they add a zoom lock (as well as a focus limiter and weather sealing - I hope you are reading this mr. Morio Ono!)
Last but not least, I have a suspicion that the distance scale window is somehow prone to being caved in - there's an unhealthy flex when I'm pressing it (or near it). Last year's copy didn't have this sort of issue. I'll probably have to tape that as well, but I'd like to see where I am focus-wise, so I'll have to find some good clear tape for this.
All in all, it looks like a great lens. Maybe it won't replace my 70-200/2.8 for demanding work (and lately I've been shooting/writing professionally once again, after a few years of break from daily journalistic work) but it's a fantastic unit to carry around every day (alongside the Canon 1D Mark 4, the 16-35/4 L and maybe one other lens - a 14/2.8 or a 24/1.4). Since my salary doesn't depend on the amount of output now, it'll be difficult to precisely assess the financial gain from owning this lens (or any other), but it has allowed me to shoot unimpeded after losing (I hope temporarily) my only lens longer than 35/50mm, and that in itself is precious. I hope to keep it for a long time and maybe even use it while travelling. Fail that, my wife may find some use for a telephoto lens... though I'm loathe to think of ever parting from it.
P.S. Oh, and from the limited time I had with the Canon 70-300 (non-DO, non-L): the Canon cannot hold a candle to this Tamron for a variety of reasons.
P.P.S. Funny that this lens looks so much like the 90mm VC macro, at least while it's retracted.