Tamron A16 SP 17-50mm f/2.8 Di II LD Aspherical [IF] Lens for Nikon DSLR Nikon F Mount Crop Frame Product Review

The Tamron 17-50mm f/2.8 XR Di II Lens delivers very good image quality in a small, light, fast and affordable package. Add in the very popular focal length range and you have a lens that is just right for many digital SLR camera owners. The early-in-its-lifecycle popularity this lens is enjoying substantiates this claim.

Like Canon's EF-S Lenses, The Tamron 17-50 provides an image circle that is large enough for APS-C (1.5x/1.6x FOVCF) sized digital SLRs sensors. Being sized for a smaller-format sensor allows a smaller design to be used. Measuring 2.9 x 3.2" (74 x 82mm)(d x l) and weighing 15.2 oz (430g), the Tamron 17-50 is an ideal size for these smaller digital SLR bodies. It balances and handles very nicely.

Build quality is not rugged, but it is solid - very adequate I would say. The included hood is similarly built. The rubber on the zoom ring is grippy, soft and deeply ribbed. The zoom and focus rings turn smoothly. Tamron's rear lens cap only attaches at one position - a bit of a pain since I'm used to Canon's 3 attachment positions. Tamron's excellent center-pinch 67mm front cap more than makes up for this pain - I've considered putting these on my Canon lenses - And many of Sigma's lenses desperately need them.

On to more important issues ... The Tamron 17-50mm f/2.8 XR Di II Lens' AF is rather fast, but the high pitch buzz made by the focus motor is deceptive - making the lens sound slower. I found AF accuracy to be quite good with relatively few missed shots (that were not my fault at least). This is an internal-focusing lens - It does not change length during focusing and the front element does not rotate. FTM (Full Time Manual) focusing is not supported. Since the manual focus ring is rather small and in front of the larger focus ring, I did not find the focus ring turning during autofocusing to be much of a problem. It does turn though. The Tamron 17-50's minimum focus distance is 10.6" (0.27m) and provides a respectable .22x magnification factor. Both the zoom and focus rings rotate the opposite direction of Canon's lens rings. A zoom lock switch is provided.

The optical quality of the Tamron 17-50mm f/2.8 XR Di II Lens is excellent (especially for the price). I find my images sharp even when wide open at f/2.8 at all focal lengths - I do not hesitate to use this lens at f/2.8. Narrowing the aperture 1 stop or so yields slightly sharper image centers and noticeably better corners as the corners are somewhat soft wide open.

If the subject or background is an evenly-shaded solid color, you might notice slight vignetting when the lens is at f/2.8 at the wider focal lengths. Otherwise, vignetting will not be noticeable. Some CA (Chromatic Aberration) can be seen in real life shots, but nothing I would consider objectionable. Flare is very well controlled. Some barrel distortion is visible at the 17mm end. Pincushion distortion becomes visible at 24mm and more noticeable at 35mm before lessening to the 50mm end. Colors seem fine - neutral. The 7-blade aperture produces pleasant out-of-focus highlights.