I went down to the Dallas World Aquarium today to give the Tammy a first run through. I spent some time last night playing with it to become familiar with it, prior to actually use. My first obvious reactions are:
*Solid feel. Despite the extensive plastics used, it feels very well built.
*It comes standard with a tripod collar, hood, and decent case.
*The AF motor is faster and more precise acting than I expected.
*AF motor still makes more noise than any USM/HSM drive.
*No IS/VC, and no current rumour of one making it as a future option.
*Typical Tammy hood (some people don't like felt, but for those who do...)
Okay, so there is my thinking prior to sleeping last night. Today I spent two hours at the Aquarium with my new Tammy on my 5D. I spent almost the entire time with it on (though I did get some lensbaby shots and contax too). In one-shot AF use, the AF motor jumps to the focus area, then seems to shift into a 1/3 speed mode to fine-tune the focus. This is great, but there is a problem...
*No focus-limiter switch! (Why?)
...and that problem shows up anytime you shoot something medium range then shoot somethingmore distant, as the goofy lens draws back to the macro range before giving up and looking elsewhere. Why Tamron built a lens with class-leading macro functionality and no focus-limiter is beyond my understanding. I would have paid the extra $25 for the switch/circuit to keep it from digging in the macro range.
Next its time to test the servo mode and answer those who say "I can't rely on anything but USM/HSM for tracking/servo use". I would have agreed with you before (and still to a point), but this lens keeps up fine with moving subjects (assuming your AF system in your camera will cope) in servo & AI-servo mode. It stays in the previously mentioned fine-tune AF motor speed and tracks along without much issue. It seems like people got by before without USM/HSM, so I guess I might survive without the luxury.
I shot some photos of monkeys (or tamarins, not sure) nestled in trees and switched to MF to keep a lock on them and not little surrounding twigs (the twigs fool the AF occasionally, but my eyes don't bite...too much ). The AF/MF clutch mechanism is functionally similar to Tokina's implementation and actually was easy to shift in and out of. The ring spins in AF with no interaction, just free-wheeling. The focus path is shortin MF mode, but not too short, IMO. It is a less dampened, though, than you would expect. It is looser than any 70-200 in the Canon line-up. That being said, I had no problem focusing with the lens. I would prefer it be slightly more dampened, though.
Okay, so when I got home, I got a chance to see the optical quality. I shot primarily wide-open, as the lighting in the Aquarium is decent to poor, and only good outside in the penguin area (though today even it was darker than normal). Much of this is due to the tree coverage shading much of the light out and letting rays poke through here and there. Anyways, the images look pretty good. I've only sampled one 70-200/2.8L IS (my friend's) and it appears to be on par or better than that lens. I have to go by samples for now as I have not yet organized a proper sampling method (maybe tomorrow, time permitting) to test its characteristics at various apertures. I must say that the color seems very good from the camera, and the images are sharp. The one issue on the 5D that you may notice is the vignetting, particularly in the "closer to macro" shots at f/2.8. It's worth noting that I can't see any visible CA in the shots I took today. Penguins are black and white, so they serve as good CA tests. I definitely feel that the lens is worth at least the $700 that it cost.
So, here are the first samples.
The first four are RAWs with no sharpening applied at any point, and I will supply full shots (resized), then 100% crops of in-focus areas. All were shot at f/2.8 and most are at 200mm.