Sigma 17-50mm F2.8 DC OS HSM Large Aperture Standard Zoom Lens for Sony Digital DSLR Camera

After purchasing this lens I had to join the chorus of praise heaped on it. I had all the intentions of getting the Canon EF-S 17-55mm f/2.8 IS to go with my new Canon EOS 60D. However the recent January-March price drop of $60 sealed the deal. I figured it was worth the gamble, or as I've often seen it referred to "the Sigma lottery". The reviews on this lens have been in for a long time, and most of them are quite positive. Some even rate this lens better than the venerable Canon EF-S 17-55. However, there is also the black cloud that seems to hang over Sigma's head - that of variable quality control. You'll see the bitter reviews of folks with bad experiences right here.If you hang around the camera forums, this can get to be even more depressing. People going through all kinds of tests for their lenses, constantly trading them back in for better copies. Or, claiming after going through 2 or three or five copies finally giving up. The brand that usually seems to pop up most often is Sigma. Perhaps because they (more than others) have a range of lenses that go toe-to-toe with the big boys. In some cases they're just as pricey as Canon or Nikkor.The 17-50 is claimed by some to be as sharp, and even sharper than the 17-55 at above f4. For almost half the price I figured it was worth a shot, and this seems to be one of those rare cases where I really feel I got my monies worth. There are some trade-offs in features, but not quality. One thing I'll mention right away that I've seen mentioned elsewhere, and that's a "rattling" noise the OS makes when you shake the lens. Now, it never occurred to me to shake my lens. But I guess I'm odd that way! So, now than I finally have the thing I shook it. You know what? I don't hear it. I mean, I can hear a bit of movement, but nothing like my EF-S 17-85 for instance. Take that for what it's worth!I decided to first test the lens on my "I know how it works and I know it's working" XTi Rebel. The first shots looked promising, and further tests showed it to be sharper than many reviews I've seen. I've posted a photo of the lens center and extreme corner at 17mm f2.8, where the lens is purported to be at its worst. It only gets better from there! After pairing to my 60D, well, keep reading!Fit and finish:This new Sigma no longer uses their matt crinkle sort of rubberized finish. While I liked the old finish, it showed marks, collected dirt and is very hard to clean. The new matt finish is smooth and nice, perhaps nicer than the speckled finish of the Canon EF-S series. The lens feels as of-a-piece, there's not a hollow spot or loose fitting anything anywhere. One complaint I see popping up regards the lens hood fit. At first I was all there with the "it barely hangs on" thing. Jeez, what's up with that? Oh. Duh. You rotate it a bit harder and it snaps in place. A firm "click". Nice. It's not going anywhere. This is very different from past Sigmas and the Canon EF-S lens hoods, which while nicely finished are still flimsy and don't fit all that great. The interior is not ribbed like old Sigmas, nor flocked like Canons, just a simple matte finish. At least it didn't cost $35! Other than that you'll find a zoom lock, AF/Manual and OS On/Off switches. One bizarre characteristic can be seen when viewing the mount and back element. If you zoom the lens out and the element travels inward, the camera's electronics are exposed! I found this weird enough to check my other lenses, and no, this is unique. I guess just don't check it out in a rainstorm and you're good to go. My final comment is that there is no distance scale window (just a distance scale on the barrel), an obvious price cutting issue. I don't really use the scale for a lens this size, but miss the little jewel like window all the same.Function:It is extremely solid and operates smoothly. The zoom is nice and smooth with a good amount of equal resistance in both directions. There is zero creep, and even still there's a zoom lock. This can't be said for the EF-S 17-55. The biggest issue I've got as others have mentioned is the overly thin rotating focus ring and short focus rotation of about 45 degrees (!) with hard stop. This is not a big issue for me in still photography, but it seems this could be a problem with video and somebody as ham-fisted as I am. The feel of the focus ring while smooth offers almost no resistance. In comparison, my other lenses are far superior in feel. Again if manual focus is a priority then this should be a consideration. The switches are a huge improvement over some past Sigmas, and each snaps quickly and firmly with identical feels. The zoom lock is quite small and there's no chance of accidentally hitting it, but it's large enough and has a positive enough feel to find and engage with confidence.Performance:The AF is fast, as fast as any lens I've got. Perhaps it's so fast because of the short focus ring distance? It's not at all noisy. No hunting, no hesitation. Even in low contrast conditions it's just bang on. Considering the horror stories I've heard about the AF, this is another one for the mystery files. OS is another thing - while I've got a pretty steady hand (at certain times of the day, depending on barometric pressure and planet alignment) I'll assume it's doing its job. All the low-light shots with slow shutter speeds I've taken look great - consistent down to 1/10. 1/6 not so much. They claim 4 stops worth so I'll assume it's 3 and call it good! The OS is not at all noisy either, it was enough to concern me at first! I had to put my ear up to it and depress the shutter to confirm its operation when I first started. Summary, AF and OS are everything they should be and more.IQ:It's incredibly sharp across the board. At 17mm and f2.8 is tack sharp center, with a slight softening in the corners - and I do mean slight. at 28mm and above it's mind-boggling. Seriously, I simply can't believe how sharp this thing is wide open. I'd have to say if there's a sweet spot it's around 5.6, but it really is wonderful up to about f/11. Typically, pixel peeping at 100% can be a depressing thing on a Canon APS-C camera. Now I just giggle!Vignetting is quite apparent at the shortest focal length as would be expected, but very evenly gradated. CA is evident in extreme corners at all ranges, most notably distant high contrast objects. On my copy it only seems to be red fringing towards the outside, highly controllable in PP. Barrel distortion is pronounced at 17mm both vertically and horizontally. In comparison, my Sigma 10-20 f4-5.6 has almost no vertical distortion at 10mm. Distortion is pretty much gone by around 24 up. Really nothing unusual for this type of lens. I've actually found my distortion problems go away after owning a lens for a few weeks anyway! Why? I tend to stop shooting brick walls and start shooting other things instead. Of course, the vignetting and distortion are easily fixed as is CA using Lightroom, Photoshop, DxO or a host of other applications.Contrast is another place this lens really shines, as what I would expect from an L series lens. Colors are deep and rich if slightly on the warm side. Flare seems well controlled, I've shot pretty much into the sun with no issues. Bokeh? Meh. It's good, pleasing actually, but nothing I'd call creamy or recommend the lens for. Bright objects do tend to have outlines, but no real fringing, odd shapes, holes or halos. You'll be able to find lots of samples both here and in reviews at lenstip dot com or photozone dot de.Pros- Great fit and finish- Excellent size and weight- Fast, accurate AF- F2.8 is better than usable!- Sharp, great contrast- Better than advertized corner sharpness- Low CA- Image Stabilization- 60% the price of the EF-S 17-55- Comes with case- Comes with lens hood- Center pinch and edge pinch lens cap like most "modern" lens manufacturers (hello Canon?)- Great warrantyCons- Skinny focus ring- Rotating focus ring- Manual focus turn only 45°- Focus ring hard stop- Mediocre focus ring feel and resistance- No full time manual focus- Vignetting at lower focal lengths- No distance scale window- Short focal length- Possible QC issues- Always run the risk of future EOS body incompatibility with third party lensesIf you need an f2.8 type lens, I highly recommend giving Sigma a look. If you're looking to replace your kit lens, or are really only going to have 1 lens you may consider something with more of a focal length like the EF-S 15-85 f3.5-5.6. Basically in this category of lenses there are only about 4 choices. The Canon EF-S 17-55, the Tamron AF 17-50mm F/2.8 XR Di-II LD SP , the Tamron AF 17-50mm F/2.8 SP XR Di II VC and this. IMHO, the Tamron lenses are out of the running for either being sharp with no VC, or not sharp with VC. Tamron build quality is good but not great IMO. The Canon is top notch IQ but not top notch build, and then (are you listening Canon?) you still have to pony up for a mandatory and potentially lens-saving hood.All I can say is this is a perfect "specialized" walk-around for crop bodies as others have mentioned. For indoor shooting it's a winner. You've got f2.8 in a small well built package that's razor sharp at f4 and above. See my chart test for opinions on f2.8. When introduced this was a pricey lens and it was hard to not consider just spending the extra $200 for an EF-S 17-55. But slowly the price has come down. At its current street price of around $650, it's a deal. Buy it, test it and if you do get a defective copy, then you've been fortunate enough to buy it from Amazon, right? Send it back and get another one, it's just that easy. And speaking of easy, this one is an easy 5 stars.

I was shooting for years with an 18-55 Nikon kit lens (on a D90); I chose to upgrade other parts of my lens family instead of the midrange zoom since it is a good quality lens for the price. But in a bad situation the camera made good friends with the pavement and the 18-55 caught the worst of it.What I was looking for that made me choose this lens:* a midrange zoom somewhere around 18-55 coverage, under $1k. I have a Nikon 55-200 and think you get better IQ by not combining the two ranges.* I've learned I prefer fast lenses since I frequently shoot in low light without a tripod and am a big fan of bokeh.* I often don't shoot in controlled environments so OS helps me get my shots. I've heard that the non-OS lenses are sharper, but I haven't noticed anything undesirable in the sharpness; and one shot you'd otherwise have missed to camera shake seems to make OS worth any loss in sharpness and increase in weight and cost.I'm extremely cautious about major purchases and spent months researching off and on. Nikon's options were more expensive, or were bringing me back to that 3.5-5.6 aperture which, frankly, is frustrating when you shoot manually 90% of the time and have to adapt quickly. Basically it was a battle between Tamron and Sigma offerings, and Sigma seems to frequently have the advantage in sharpness. Obviously both have their proponents but I have no personal experience with Tamron, so that combined with reviews led me here. This is my 2nd Sigma; I also have the 10-20 f/3.5 which is a stunning lens, and have shot with a Sigma zoom on a 35mm cam. While you will read a lot about quality control issues with third-party lenses, don't let it scare you off; just buy from a reputable seller and check the lens for any issues/decentering as soon as you get it. If you get a lens everyone else loves and you think is awful, swap it; it's QC.I'm still "learning" the lens since I've only had it about three weeks, but so far very impressed with it. The IQ is about the same as my 10-20, which under the right conditions will knock your socks off like a 2-3x pricier lens. Rich, realistic colors, sharp in the right places, and good contrast. Focus is fast and quiet (heard the Tammys sound like a dying robot). I'm obsessed with extreme close-ups of small things and like to get right in there with lenses, and have actually found you can get the lens to focus within its official max distance (managed about 8" from an object). You can get really stellar depth of field stuff with the 2.8 aperture, and it's smooth and even too. If you have a fondness for bokeh you're unlikely to go wrong. I'm a "serious hobbyist" I suppose, but this lens at this price would probably please a pro. I used credit card points to bring the price down which was a help, but I'd have paid full price for it.Pros:- overall image quality; good contrast, bright and rich colors comparable to a good Nikkor, good sharpness across lens- 2.8 constant aperture (once you've got constant aperture on a zoom you won't want to go back)- buttery smooth bokeh- optical stabilization- price to quality ratioCons:- relatively large and heavy- stiff zoom ring. VERY stiff. I hope it will loosen. (I have quite small hands so it may be less trouble if you don't.)- easy to snag rotating focus element on your fingers if you're not careful about your grip (not a big deal though)- large filter size (don't let this put you off; it's not a reason to pass on a lens)- very minor con: for some reason Sigma lens caps have a nasty habit of popping off without notice. Keep an eye on it.The pros definitely outweigh the cons though. This was my top choice after months trying to manage with only a Nikon 35mm 1.8 (wonderful lens, not ideal for everything though!). The combination of sharpness, color/contrast, bokeh, OS, and price make it an excellent choice the vast majority are unlikely to regret. I certainly prefer it to shooting product photos with a wide angle (fun times)!Quick note: Sigma lenses come with zippered cases, not pouches like Nikon; they have stellar padding but are bulky. If you ever transport your lens in an individual case while shooting, I recommend having a second case/pouch for it. I got a Domke lens wrap for putting this in my converted messenger bag.