Finally a lab test of Tamron AF 17-50mm f/2.8 XR Di II LD VC

>> The biggest weakness of the lens is the rather soft corner/border performance at large aperture settings. The quality increases when stopping down and it's certainly possible to achieve very high quality results from f/5.6 onwards (a bit of corner softness remains at 17mm). <<

Yeah, great - use at it 5.6! That beats the very purpose of buying a constant 2.8 aperture zoom lens. I bought this lens in December, exchanged it due to a F-- error, and returned the exchange after 5 days. I am not a pixel peeper, but the lens did not meet my expectations as a serious amateur :-(

Sadly Nikon does not have an equivalent lens (their 2.8 zoom does not have VR).

this review clearly states the VC model has worse IQ than the original model (which is fairly sharp at 2.8). the review is for canon mount, however.

I've been very interested in this lens, but since the review is for Canon, I'll tell ya' what I'm gonna do; go over to Samy's Camera (near me in Los Angeles) and test the lens for myself on my D70s, and on one of their D300 (the camera I intend to buy). I may even try a couple of the lenses just to check variations from lens to lens. This will be a real world test, of the sales people, the countertop, shelves, wide open in mixed light.

I don't find these strickly MTF-based evaluation too meaningful. Mind you that even the Nikon 17-50/2.8 only eared three star in their "optical quality" test. This emphasis on corner to corner sharpness is not always relevant to the way that we shoot. For example, most of the people would use f2.8 to achieve shallow DPF to pop the subject in the center of the frame; thus, what is the big deal if the corner is "soft?" If you compare the MTF number between the Nikon and this Tamron lens, you will find that even though the center performance of the Nikon is not too far off from that of the extreme corners, in terms of the absoulte MTF score, the center from the Tamron lens is in fact sharper than that from the Nikon:

Nikon at 2.8 from center to the extreme corners:
2000, 1800, 1500

Tamron:
2300, 1800, 1400

The dependence on MTF test in many ways may be misguided. It is easy to conduct the test by shooting a fixed target in the studio but how this lens performs in the field is often another story all together.

While I generally trust photozone reviews I fully agree with CC Chang here. While I do not own this lens I did PP for about 800 pics done by a friend of mine in available light at a conference, using only this lens mounted on a D90. Honestly I was pleased with results... I also borrowed it for a couple of days just to check the quality of VC... and it's impressing. Only when shooting in low light on noncontrasting surfaces I was dissapointed by it's merely hunting behavior.

Sure, I will not recommend this for a pro shooter... but for a person that is on a low budget this is a very decent lens.

good point, CC. photozone's MTF tests appears to confirm the 17-50 is sharper than the 17-55 at 2.8.

last night, i was shooting with the 17-50 in extreme low-light conditions (inside a dimly-lit nightclub, no flash). corner performance was essentially meaningless. the tamron+d300 combo did pretty good at 2.8, 1/200, iso 3200.

Pretty much every lens I have hunts in low light, low contrast situations, but I'm glad to hear that real world and center sharpness is good. I'm a professional and have no qualms what-so-ever using this lens, or any other quality third party lens for my work (Tokina 12-24, Sigma 50-150 in my bag).

i think sometimes people hunt for reasons not to like 3rd party glass other than its not OEM, and, at times, it's a bit of a reach. the fact is the third-party guys make lenses which plug gaps in the Canon/Nikon lineup, and some of them are gems. to me, its not about being a nikon fanboy, it s about having the right tools to get done what you want to get done.

I have the original (non-VR) version of the Tammy (sic). I have sold more prints from that lens than from any other I have owned. And I really can't see much reason for VR at a 75mm equivalent.