The Lens Nikon Hasn't Made (well, one of them)|
||17 elements in 13 groups; 2 FLD low dispersion elements.
||Optical stabilization, HSM (AF-S equivalent) focus, Internal focus, 77mm filter size. Comes with petal hood, 7-blade rounded aperture. Focuses to 11" (0.28m).
|Size & Weight
||About 3.6" (92mm) long from mount, 19.9 ounces (565g).
One of the top requests from users of any system is an optically good, fast aperture, optically stabilized mid-range zoom (moderate wide angle to moderate telephoto). In the pro ranks, similar lenses form the middle of a workhorse trio of lenses (wide angle zoom, mid-range zoom, telephoto zoom), so it's not surprising that DX users would want the workhorse, too.
Nikon's solution appeared in 2003, the US$1400 Nikkor 17-55mm f/2.8. It's optically good, has a fast aperture, but lacks optical stabilization. It's also big and heavy, and that price tag means that it's more expensive than all but one of Nikon's DX cameras. In other words, it wasn't exactly embraced by users, though I found it to be a very good lens in practice.
Over the years, there have been quite a few third-party attempts at doing better than Nikon, with the most notable ones being the Tamron 17-50mm f/2.8 (first without a focus motor, then with a focus motor, then adding image stabilization), and a pair of Sigma's, the 17-50mm f/2.8 and the 17-50mm f/2.8-4 (both of which appeared briefly without stabilization, then with it). I'm not going to do reviews of all of these lenses, so I should probably tell you why:
Sigma: the variable aperture versions of these lenses, while less expensive, simply don't perform at the level I'd want them to. They're much more like kit lenses that are 1/2 to 2/3 of a stop faster. We don't need more kit lenses.
Tamron: the original version of the lens I liked, but the addition of the in-focus motor actually hurt this lens considerably. It doesn't have the focus performance that the Nikon or Sigma solutions do, which makes it somewhat non-competitive in my book.
Which leaves us with the Sigma 17-50mm f/2.8 OS HSM, the subject of this review. I have to say I was skeptical when I saw the specs and the price. Sigma's reputation for wide sample variation also didn't make me expect a lot, either. But I decided to try it out, and have been quite pleased I did.
If you've used the Nikkor 17-55mm, the first thing you notice is that the Sigma is smaller, lighter, and more compact. It feels "more DX" than the Nikkor, and the size is very appropriate on all the DX bodies. No longer do you feel front-heavy as you do with the Nikkor 17-55mm on some DX bodies. A photo tells you all you need to know:
Sigma 17-50mm on left, Nikkor 17-55mm on right
One way Sigma achieved this is a very tight-to-DX image circle. Typically, that would mean vignetting and poor corner performance, but we'll get to those things in the performance section, further down in the review.
The 17-50mm has two of Sigma's latest technologies in it, paralleling Nikon's: HSM is Sigma's version of AF-S (internal focus motor), and in my experience, has similar performance; OS is Sigma's version of VR (optical stabilization), and given that Nikon has been suing Sigma over copying Nikon's VR system, it too has very similar performance. You'll notice that things are starting to stack up in favor of the Sigma: price, size, optical stabilization, but nothing is yet detracting from it (similar focal range, same f/2.8, etc.). Pay close attention to that and you'll see why I recommend this lens.
There are focus markings at the very front of this lens, but no DOF or IR markings. The lens is marked at 17, 21, 28, 35, and 50mm on the zoom ring.
Like most traditional lenses, the focus ring is furthest from the camera, the zoom ring closest to the camera.
The 17-50mm is an internally focusing lens, so the front element doesn't rotate during zoom or focus. Close focus is about 11" (.28m), which is very nice, basically as close as some wide zooms go. The lens uses 77mm filters.