Sigma 17-50mm f/2.8 EX DC OS HSM
Lab Test Results
September 5, 2012
by Andrew Alexander
Announced in February 2010, the Sigma 17-50mm ƒ/2.8 EX DC OS HSM provides third-party competition in the short zoom lens market. This is the first zoom lens produced by Sigma in this range that provides both a fixed maximum aperture and optical image stabilization.
Designed for the APS-C sized camera bodies, the lens provides an effective field of view of 27 - 80mm (Canon) or 26 - 75mm (Nikon and others). The LH825-03 (583) petal-shaped lens hood ships with the lens. The lens takes 77mm filters and is available now for around $700.
The Sigma 17-50mm ƒ/2.8 OS offers sharp central performance throughout its zoom range, with varying degrees of corner softness. This corner softness is improved as the lens is stopped down, and there are a few points of tack-sharp image quality.
Used wide open at wide angle (17mm, ƒ/2.8) produces the ''worst'' corner softness - but even here it is comparatively light, matched nicely with a generous central area which is very sharp. As the lens is stopped down this corner softness abates gracefully, offering excellent sharpness by ƒ/5.6 (which is actually the best setting: diffraction limiting appears to set in at ƒ/8, noticeable by ƒ/11). Stopping down to ƒ/16 or ƒ/22 produces light softness across the frame.
The preceding is actually a good descriptor for performance in the other focal lengths, with a single noteworthy observation. Zoomed in to 21mm, 28mm or 50mm, corner performance is actually slightly better at these focal lengths, but there is an interesting deviation at 35mm where we see corners similar to those at 17mm. These are small numbers, so it's doubtful that you will see a meaningful impact in real-world photography, but it's interesting to note.
The sharpest point for this lens appears to be 50mm at ƒ/8, where performance is essentially tack-sharp across the frame.
The Sigma 17-50mm ƒ/2.8 produces CA of the magenta-green variety, noticeable in areas of high contrast, and predominantly in the extreme corners. It's mostly significant when the lens is used wide open, though zooming in does appear to limit its presence.
Corner shading isn't a huge factor with the Sigma 17-50mm, producing (at its most notable) extreme corners which are just over a half-stop darker than the center of the frame, when the lens is used at 17mm and ƒ/2.8. Other focal lengths used at ƒ/2.8 produce around a third of a stop darker corners; other apertures do not produce any significant corner shading.
Distortion is typical for a wide-angle zoom lens; barrel distortion when zoomed to wide, approaches no distortion in the middle, and gets a bit of pincushion distortion at the telephoto end. At its worst, distortion is around 0.75% barrel when used at 17mm. The distortion is fairly linear, and meets at the zero-distortion point at around 24mm. After that it's pincushion distortion in the corners: about -0.3%. You can turn your curves back into straight lines easily with most image processing software.
The Sigma 17-50mm ƒ/2.8 OS is designated as an HSM (hypersonic motor) lens, but it doesn't share the full implementation of what we've come to expect from Sigma's HSM lenses. Specifically, it doesn't feature full-time manual override, so if you want to override autofocus results you must first disengage the autofocus. Due to the lens' short focus throw, focusing is quite quick, at around one second to focus from close-focus to infinity, and the lens makes very little noise in the process. Attached 77mm filters will not rotate while focusing.
The lens offers fair macro performance: 0.2x magnification, with a minimum close-focusing distance of 28cm (just under one foot).
Build Quality and Handling
The Sigma 17-50mm ƒ/2.8 OS features an all-black, all-plastic construction; parts of the lens are coated with Sigma's rubberized coating, which offers good traction. There are two switches on the lens, one to activate or deactivate image stabilization, and one to enable or disable autofocusing. The lens features a distance scale, but doesn't offer a depth-of-field scale. The lens mount is metal, and the 77mm filter threads are plastic. The aperture is made up of seven curved diaphragm blades, which should offer pleasing out-of-focus background elements.
The focus ring is mounted at the end of the lens, 3/8-inch wide and composed of raised rubber ribs. As mentioned, the focusing range of the ring is fairly small, only 45 degrees, making manual focusing a bit tedious. We found that the focus ring has very little dampening, letting it turn very freely. The focusing throw is bounded on either side by hard stops. The front element doesn't rotate while focusing.
The zoom ring is the larger of the two, 3/4-inch wide, also composed of large raised rubber ribs. There are around 45 degrees of rotation in the zoom ring, and a nice level of resistance to the ring; not too tight, and not too loose. There's no evidence of zoom creep, but Sigma does include a zoom lock to fix the lens at 17mm so the lens will not extend while dangling on your neck strap.
The Sigma 17-50mm f/2.8 OS employs Sigma's optical stabilization. In our testing of it, we noted 2, if not 2 1/2 stops of hand-holding improvement: check our IS Test above for further detail.
The included lens hood (LH825-03 583) is of the petal-shaped design, adding a further 1 1/2 inches to the overall length of the lens. The interior of the hood is deeply ribbed to reduce the impact of any stray light entering the front element, and the hood can be reversed onto the lens for storage.
Tamron 17-50mm ƒ/2.8 XR Di II VC LD Aspherical IF SP AF ~$650
Tamron's design has been around a while: Sigma's offering tests as slightly better, with better results for sharpness and corner shading. Operationally, they are about the same.
Sigma 18-50mm ƒ/2.8-4.5 DC OS HSM ~$400
If you don't need the constant f/2.8 aperture, Sigma offers a slightly less expensive variable aperture lens which also tests very well.
Canon EF-S 17-55mm ƒ/2.8 IS USM ~$1,150
Canon's offering in this category is about twice as expensive, and offers similar if slightly better performance than the Sigma. Operationally the autofocus system is much better and potentially the build quality as well.
Nikon 17-55mm ƒ/2.8G ED-IF AF-S DX ~$1,250
Nikon's offering in this category is about twice as expensive, and offers similar performance. Nikon's autofocus system is better than Sigma's in this case.
Pentax 16-50mm ƒ/2.8 ED AL IF SDM SMC DA* ~$750
We haven't yet tested Pentax's offering in this category.
Sony 16-50mm f/2.8 DT SSM ~$700
Sony's offering is similar to Sigma's but probably represents a better value: it's about as sharp, but uses better SSM focusing than Sigma's implementation of HSM.
There's no shortage of lenses to choose from in the short zoom category, and Sigma's offering presents an economical alternative to the major manufacturer's options. Optically it tested well, and it's not too hard on the pocketbook.
The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.
As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.
Sigma 17-50mm f/2.8 EX DC OS HSM
Sigma 17-50mm f/2.8 EX DC OS HSM User Reviews
6 out of 10 points and recommended by joe88 (37 reviews)sharp in centrewide open wide angle not so sharp in the corners; CA's
suitable for portraits, for my taste wide open too much CA's on extreme wide angle, not so good for architecture, good lens, but not an excellent onereviewed January 31st, 2014 (purchased for $350)
8 out of 10 points and recommended by Lamar (1 reviews)Lighter, Less Expensive than the Nikon option. Generally very good overall sharpness and excellent in the center. StabilizationCorner softness at f/4 or less when wide.
I wanted a fast normal zoom to use with my D300. Based on the many reviews online it was easy to narrow my decision down to two choices, the Nikon 17-55 f/2.8 or the Sigma 17-50mm f/2.8. I decided to get the Sigma since it was half the price of the Nikon and had VR. I have never used anything but Nikon glass for my Nikon cameras so this was outside the box for me. I was concerned about build quality and image quality, sharpness in particular.reviewed December 7th, 2012 (purchased for $609)
The first lens I received had an obvious alignment problem, the left side of the frame would be very soft while the right would be sharp even at f/8 on equidistant objects. I exchanged the lens for another sample.
When I got the new lens I shot test images using a D300 to compare the Sigma 17-50mm f/2.8 OS HSM lens to Nikon's 18-70mm f/3.5-4.5 AF-s and 18-200mm f/3.5-5.6 AF-S VR. I was specifically interested in determining whether to keep the Sigma or return it and get the Nikon 17-55mm f/2.8 for TWICE the price. After seeing the results I decided to keep the Sigma. It's faster and sharper than what I was using, it's half the cost of the equivalent Nikon option, plus I get VR. Central sharpness on the Sigma is excellent. Corners are soft at the wider settings below f/5.6 but as focal length increases past 35mm the image sharpens up nicely even wide open everywhere but the most extreme borders.
Link to images: <a href="http://www.lamarlamb.com/Things/Testing-Sigma-17-50mm-f28-OS/26935388_MqHphg#!i=2257949078&k=QzNjTXT" target="_blank">www.lamarlamb.com/Things/Testing-Sigma-17-50mm-f28-OS/26935388_MqHphg#!i=2257949078&k=QzNjTXT</a>
9 out of 10 points and recommended by jho (1 reviews)Sharp, fast and accurate focus, image qualityOccasional focus hunting in very low light
Prosreviewed September 22nd, 2012 (purchased for $590)
Image quality excellent.
AF performance excellent.
Build quality very good
Excellent image resolution
Excellent low light performance
Hood and case included
Just over half the price of the Canon 17-55
Easily the best buy in this focal range.
I would highly recommend this lens any day.
No AF manual override
9 out of 10 points and recommended by hudson46 (1 reviews)Ease of use, image quality, OS, buildLack of full-time focus, lack of hyperfocal markings
Had to choose between Canon 17-55 and this Sigma. Tried both, and very happy with the Sigma. Image quality is superb, as good as an L-lens I borrowed for a while. Manual focus is tricky, with a short turn (30 degrees?) and distance scale is therefore cramped, making hyperfocal settings tricky - I do a lot of landscape and outdoor work. Working round lack of full-time manual focus is a little annoying, but I got used to it fairly quickly. Switches for OS and Auto/Man focus work well, as does the zoom lock, just in the right place.reviewed August 7th, 2011 (purchased for $930)
Overall, very satisfied with this Sigma 17-50. Excellent choice as replacement for standard kit lens, as well as Canon 17-85. Slightly better in my opinion than the Canon 15-85.
Had to return the lens direct to Sigma for autofocus problems, but returned to me in one week, focus fixed, lens better than ever.
8 out of 10 points and recommended by bridges (4 reviews)fast, smoothsize, zoom ring turns 'wrong' way, plastic filter ring
Zoom is smooth like other recent sigmas, HSM is fast, quiet. Hood is smooth to put on, but feels not secure.reviewed November 8th, 2010 (purchased for $670)
Construction feels solid, tho I prefer Nikkor ON/OFF switches to Sigma's.
There's no full time manual override, not an issue for me. Zoom turns the wrong way, that's quite poor on their part. No weather sealing, also a bit poor since it'd be trivial to add that rubber seal at the mount at least.
Barrel extends when zooming, and the Barrel surface itself isn't smooth, that doesn't feel so good.
9 out of 10 points and recommended by jsonic (1 reviews)light, well build, near silent OS, superb opticsfocusring does turn and no full time manual focus
I was waiting for this lens to become available as I was looking for this type of lens for shooting weddings. I also looked at the Canon 17-40 4.0L and EF-S 17-55 2.8 IS I was very interested to see how well the new FLD glass would perform after reading very good reviews of other lenses with this type of glass. After comparising the lenses I dropped the Canon EF-S 17-55 2.8 IS from my shortlist mainly due to the high price and less than stellar build quality. The 17/40 4.0L is an impressive lens with stellar build quality but does not have IS. I do consider IS and 2.8 as a bonus as light conditions during weddings can be very troublesome so having a 2.8 lens can help focussing (also 2.8 means high precision AF) and IS helps to avoid camerashake so I can use slower flash sync speeds to get a more natural looking picture when flash is needed.reviewed June 24th, 2010 (purchased for $765)
So I went home with the Sigma and boy does it perform... It is stunningly sharp even wide open and it gives me very clear, brilliant beautiful pictures with great microcontrast. It has the same brilliant high quality picture feel as for instance the 70-200 4.0 L IS
The FLD glass sure is doing a great job as abberations are almost completely absent as is purple fringing that can be a pain on these wider lenses (my Canon 20-35 has very high levels of it) I did take a picture of a military chopper against a very bright sky and there is none aberation visible... Compared to my Canon 20-35 and even my Sigma 24-70 2.8 HSM it has clearly beter optics as also the distortions are well controlled. Bokeh quality is also good, it has rounded blades which give a nice even background blur.
Mechanicaly it was suprising to see a rotating focus ring on a EX lens. I guess it is done to keep the lens as small as it is. ALso full time manual focus is not available. Both points are a pity as it would have it made mechanical and ergonomical even better. The AF is on the other hand very precise and fast, I had no problem tracking cars that where doing 70kph. The OS is the best I have seen from Sigma yet, it is completely silent (in fact I had to held my ear on the lens to hear it as I thought that it did not work) It is also effective. There is no play in the zoom and focus ring and the tube when zooming out to 50mm has no play as well. Although being light it does have a quality feel about it as to be expected of an EX lens. The swithces are precise and have a nice click to it, a definite improvement over earlier lenses.
So all in all I am very content with this little marvel and I am looking forward to do my first weddding shoot using it.