The Tamron SP AF 28-75 F/2.8 XR Di LD Aspherical (IF) Macro is a high-end consumer zoom lens with a lot to recommend it. The zoom range is an ideal replacement for the so-called "normal" 50mm lens, giving considerable versatility.
Bottlebrush with Tamron SP 28-75mm F/2.8 XR Di AF Lens for Nikon AF-D
The range from 28 to 75mm is similar to the kit lenses provided with many SLRs these days. However the large constant f/2.8 aperture, and its excellent performance put this lens into very serious consideration as a standard zoom lens for users at all levels.
The construction is of a high standard, though polycarbonate has been used to reduce weight. This is not a bad thing - engineering grade polycarbonates are equal to metals for all practical purposes in this type of application. The lens mount is of metal.
In the hand, this lens feels solid and well made. The zoom and focus (despite its very short throw) are smooth and well damped. Although relatively small and light for a lens of this speed and range, it has a feeling of quality construction. The autofocus is very fast and accurate, with no hunting.
Optically, it is sharp, contrasty, and controls flare well. The very slightly warm colour rendition is pleasing. Performance at wide open is not quite as good as when stopped down, but it is still quite usable - the lens is not "soft" at any aperture or any focal length.
Distortion is not as good as the Nikkor 28-105mm, but that lens is a standout zoom as far as distortion control is concerned. I would suggest that anybody looking at this lens for architectural photography should check it out first. But for general work, the distortion is not an issue.
Although this is not that important, the front element does not rotate during focusing or zooming. On the Nikkor 28-105mm, (even though it is an IF lens) the front element does rotate while zooming.
Would I buy this lens myself? No - But only because I already have the excellent Nikkor 28-105mm. If I was looking for a serious lens in this range (perhaps to replace a kit lens) then the Tamron SP AF 28-75mm F/2.8 XR Di LD Aspherical (IF) Macro would be very high on my list of candidates.
Another Nikonian based in Japan, has reported that the prestigious Asahi Camera magazine tested the Tamron 28-75mm and it got 4 stars out of 5. Strangely enough their lab concluded edges are sharper at 75mm than the center.
Overall, Asahi Camera said this lens was very close in sharpness to the Nikkor, but there were huge inconsistencies in production. We have not been able to confirm this variation ourselves, however, if you buy this lens, buy it new and buy it locally so you can exchange it if you get a not so good sample, in case they do in fact exist.