7 out of 10 points and recommendedVery sharp, when done rightFocus is unreliable, unless...
I have to agree with many of the people here who brought up focus problems. I am new to DSLRs but have been taking digital pics for several years with good cameras, and never had this much problem getting an in-focus shot. It probably is low light most of the time, but I found a workaround, although it takes longer to achieve: My new Canon xSi has the option to use Live Mode focus during live view on the LCD, and I get far superior focus this way which no doubt allows the lens to achieve its full potential. Using live focus, I can see every brick in the highrise maybe 1000 feet outside of my window, but the shot I took with standard focus was noticeably fuzzier. And many of the first shots I took at dusk yesterday, were horribly blurry even though I did everything right. I'd have gotten better results with my point and shoot.reviewed June 6th, 2008 (purchased for $89)
I was thinking of returning this lens, but now that I know I can get razor sharp shots even in very low light using Live View, I'll probably keep it as something to experiment with to get the full potential of my great new camera at a low cost.
8 out of 10 points and recommendedVersatile, very good photos if you know what you're doingSome chromatic aberration at edges
Important update: I discovered today, a year after posting the review below, that in fact this lens takes quite sharp photos wide open, but you have to focus manually, or use the slow focus in live view on a Canon. The autofocus just doesn't deliver at 18 mm f/4.0, but if you use live view you can make it as sharp wide open as at f/8. (see below)reviewed June 28th, 2008 (purchased for $399)
After buying my Canon xSi I quickly concluded that I was not going to be satisfied unless I had a zoom of some kind to go with it. For a walk around lens, the modest 18-125mm range that this zoom offered, which is moderate wide angle to moderate telephoto, sounded very appealing. I am not all that keen on sports or wildlife photos, so I eschewed the available super zoom lenses, not just for cost but for weight, size, and image quality issues. I waited for several weeks to see if they would ever do a test of this new OS version of this lens on this site, or for anyone else to post a review, but since that didn't happen I took the plunge and don't regret it. So now I'll post the first review:
I've done pretty extensive tests on this lens, taking many tripod shots out my window in Chicago, trying different apertures and focal lengths, and comparing them to my two Canon lenses, and found it compared favorably. I found the Sigma's photos to be good looking and always in focus.
The OS works pretty well, and I was able to take two perfectly clear hand held shots at full 125 mm telephoto at only 1/15 of a second, though I had to use my best technique, as I suspect at full tele it's not hard to overwhelm the OS. Two more identical shots taken without OS were both blurry.
I've taken a few thousand shots with this lens so far and have no focus problems. Focus is fast and quiet. I took a number of shots of seagulls at 125mm, and every one was in focus. Here is a 100% crop example:
(This shot is cropped to remove a lot of sky. Please note that you can't get this close to a bird in flight with a 125mm, but it is still a clear photo)
At 18mm this lens is a tiny bit less sharp than Canon's well-regarded 18-55mm IS kit lens that came with the camera, but as you zoom in the Sigma gets better, particularly at 50mm. Here is I shot on Flickr taken with this lens at 18 mm. Unfortunately Flickr rezzes the image down a great deal so you can't see it in all its 12 megapixel glory, but this will give you some idea.
I will say that this lens requires you to stop it down for the sharpest images, while the Canon 18-55 IS is more forgiving if you shoot wider. You MUST stop the Sigma down to somewhere in the range of f8 to f10 for best results (using autofocus) at all focal lengths, and this makes the OS all the more necessary. I would not recommend using this lens wide open at any focal length (unless you focus manually). But once I knew what I was doing I took some very sharp shots indeed. Here's another one at f8, 125mm
Canon doesn't yet have a zoom for digital cameras with this same range, and the closest thing they do have, the 17-85mm, is more expensive and didn't perform all that well in slrgear.com's tests. The non-OS version of this Sigma did arguably better than the Canon in those tests, and two and a half years after its predecessor's debut you would hopefully expect this newer version of the Sigma to have at least a few refinements to the IQ, but I have no way of knowing that for sure.
The telescoping part of the lens is very tightly constructed, with no looseness or feeling of imprecision at all, unlike the Canon kit lens. It has a zoom lock, but this doesn't seem to be necessary as there is no lens creep. I found this lens to be very well built and solid.
This is not a light lens. At about a pound it is twice as heavy as the Canon 18-55mm IS kit lens. Still, some of the superzoom digital lenses by Sigma and Tamron such as the 18-250mm weigh quite a bit more.
Overall I would say this is a very nice lens and I would buy it again. If you want the option to have one lens you can leave on the camera while travelling around, and if you're hooked on wide angle as I am, and if you also like telephoto but don't need a 200 or 250 mm superzoom and all the image quality compromises that can entail, this is the best and only choice for Canon APS-C digital cameras that I know of at this time, and I would recommend it.
Update: I would like to add to the other reviewer's comment about the OS staying on for maybe a minute after the shot. This does seem to be a bit of a problem, since all the time it is on it is running down the battery. I don't know why they did this; the stablized kit lens that came with it deactivates seconds after each shot, and the battery seems to last longer with it. But I've discovered an easy workaround for the Sigma, at least with a Canon xSi: Just hit the ISO button, and the OS instantly goes silent, and presumably inactive.
5 out of 10 points and not recommendedLooks like it would be sharp, if it focused with my Canon xSiAutofocus doesn't work with Canon xSi
I hate to give this lens a negative rating, because it appears to simply be an incompatibility problem between the lens and my new Canon xSi, but it NEVER focuses perfectly using the standard through-the-viewfinder autofocus. It seems to focus quite well when using the camera's slow live view focusing system, (which seems to work well with all lenses) so I can tell that probably the only fault with the lens is that it simply doesn't work with my new Canon. (The lens predates the camera by three years, so you can't really "blame" the lens; it's the manufacturers who have no interest in being compatible with third party lenses. Canon warns you not to buy third party lenses, though that's what all manufacturers say). I went through the hassle of getting two of these, and neither focused properly. It might be a Canon firmware deficiency , but there is no update for the xSi firmware at this time. I wanted to warn anyone else out there that I've tried two of these, and neither worked well except when using live view focus, and so I must reluctantly return this one and perhaps go with the Sigma 10-20 mm and cross my fingers.reviewed August 28th, 2008 (purchased for $450)
UPDATE: Canon did issue a firmware update for the XSi, and although they don't say that it helps autofocus, it sure seems to me that my Canon f/1.8 50mm lens, which never used to focus well, now seems to focus much better. Of course the firmware update was issued two days after I returned the Tokina. Wish I had it back now, though the Sigma 10-20 has given me a number of very nice photos.
7 out of 10 points and recommendedSuper-wide, good focusSoft corners
My first choice had been the Tokina 12-24mm due to the excellent analysis done here at slrgear as well as Ken Rockwell's reviews. However, it simply didn't focus on my Canon XSi. I don't know why this has happened now twice on this camera, and wouldn't you know it, a firmware update that might have helped was released two days after I returned the lens. But since the Tokina failed for me, probably due to no fault of its own, I went with this lens, and am fairly well pleased with it.reviewed September 12th, 2008 (purchased for $500)
Like my other Sigma, the 18-125 DC OS, the focus is fast and reliable, and I don't think I've gotten more than a couple of out of focus shots in the first week of ownership. The center is always quite sharp. This is my first EX quality lens, and I was surprised that after pretty careful analysis of tripod mounted test shots at all f-stops, there was almost no visible difference between f-stops anywhere in the frame after you get above f/5.0. The analysis on slrgear suggests that the lens works best at f/8, but I haven't seen that yet. It doesn't seem to be necessary, which is nice. The center is always very sharp and clear. 10mm is hugely wide, and as you'd expect kind of "bulgey". I'm not sure I need such extreme wide angle, but I will find out when I go to Italy and find myself in cramped medieval streets surrounded by potential photos.
I don't understand or believe slrgear's analysis of chromatic aberration for this lens; just as Ken Rockwell's test shots showed, this lens has low CA in actual use, far less than the Tokina. It's barely noticeable.
Now for the downside: At 10mm it gets pretty smeary around the edges. Yes, I was pixel-peeping--I admit it, and the end result in a print would probably be fine. It may depend on the subject. This shot is from Chicago:
It is unfortunately rezzed down by flickr, which can't be helped.
Based on reading reviews of this lens's direct competitors including the Canon, it sound like the deficiencies I described above are typical of super wide-angle lenses. None of them had perfect edge sharpness.
9 out of 10 points and recommendedExcellent center sharpnessNeeds to be stopped down more than the tests indicate
I have to say that this lens takes amazingly clear photos at fairly wide apertures. It doesn't hurt that it's connected to my 24 megapixel A77, which itself is an amazing camera. The two together almost never flub a shot; they're almost always clear, sharp, and in focus. The color might be a little warmer than I like (My other camera is a Canon, and their lenses seem to have cooler color temperatures, which I like), but I'm sure I can make any adjustments I need in the camera settings. The widest setting 16mm is excellent, corresponding to 15mm on a Canon. I was able to capture an entire 20 story building from just a couple hundred feet away, and the in-camera distortion correction ensured that it looked nice and square, without curved lines.reviewed December 25th, 2012 (purchased for $750)
I agree with most everything else I've heard others say about this lens; that it's heavy, well built, has distortions that the firmware corrects, and all that. One thing that I disagree with almost all other comments on this subject, is that at 35mm and above I find I have to stop it down to f/5.6 before the corners and edges sharpen up to their best. The center does indeed seem very sharp to me at most settings, but the edges tend to show a bit of smeary fuzz without stopping down. The review at photozone.de seems to bear out my findings. One does have to remember that this is an unusually wide angle lens, and I suppose that they are harder to engineer than more conventional focal lengths.
Update: OK I tried some more shots out my window and can say that the lens does indeed provide very good sharpness from edge to edge at f/4.0 and above, but only at 16mm. This is great for me because the wide focal length is the reason I bought this lens in the first place, and it turns out that it's been optimized for maximum wide. Above that, at 24mm and 35mm, I find that the edges and corners snap into maximum clarity right at f/5.6. As for the center, it seems almost indifferent to the aperture. It's sharp at just about every setting -- maybe a little softer at f/2.8.
8 out of 10 points and recommendedsmall and light, reasonable price, very good image qualitynothing important
I have owned a number of aps-c cameras and lenses at this point and have concluded that size and weight are an important factor in the kind of photography I like to do, which is travelling and walking around. I find that this lens fits the bill very nicely. Of course the lens must also take very good quality photos, and this lens doesn't disappoint as long as you stop it down to f/5.6 or f/8, depending on the focal length. This is not a "bright" lens of course, but Nikon's new image stabilization is so much better than the old one that you can actually see it in the viewfinder; the viewfinder seems to be almost locked on the image so that even a good jiggle doesn't move the scene very much. This compensates quite a bit for the smaller aperture. I own the other two popular Nikon kit zoom lenses, the 18-140 and the 18-105 and am impressed with both. This lens offers similar image quality (with a much smaller zoom range) but with far less weight, and I expect that it will be the one I use the most for casual shooting. Please be aware that on my d7100 I had to set the AF fine tune to +6 or +9 for best results, similar to what I found with the 18-140 lens. C'mon Nikon, get it together with this focus thing!reviewed February 1st, 2015 (purchased for $246)
9 out of 10 points and recommendedEdge to edge sharpness, minimal light falloff at the edges, useful zoom rangeNo stabliization, not super sharp at 28mm
I got this for my Canon 60D. Excellent image quality across the entire frame, and the good zoom range means that you can leave it on the camera as a walkaround lens. Compared to my Sigma 17-70, which is a very good lens, I noticed that the edges of the Tokina were bright and clear without any compensation. I only wish that they made this for Sony so that I could put this on my A77 with its in-camera stabilzation, and then this lens would rule!!reviewed May 2nd, 2014 (purchased for $490)
10 out of 10 points and recommendedNice range, brighter than most zooms, sharp, compactnone
I am on my second Canon APS-C camera, a 60D, and have been using the earlier non-STM version of the EF-S 18-135mm lens. I thought that this camera and lens combo did a pretty good job, and in most bright outdoor travel photo situations compared pretty well against my "better" camera, the 24 MP Sony A77 with the 16-50mm f/2.8. I have had my eye on the Sigma 17-70 for several years, and with this third iteration (the Contemporary or "C" version) when the price dropped to $449 I decided it was time to jump on it. I'm really glad I made the investment because now with this lens I feel like I'm seeing for the first time what an excellent camera the 60D is, especially in conditions of reduced available light.reviewed February 8th, 2014 (purchased for $449)
Compared to the Canon 18-135, the additional wide view provided by the 17mm Sigma versus Canon's 18mm is noticeable and much appreciated. It's a lot more compact and has only a little lens creep, unlike the Canon, which has terrible lens creep. Every time I tip the Canon lens down to look at the LCD display on the camera, the lens telescopes out almost to the full length, and I have to recompose the shot. I will not miss the additional zoom the Canon affords because I'm not much interested in photographing sports or birds, and there is no lens I know of that possesses a long zoom range that also has brightness and sharpness. Nearly all of my favorite photos fall into this lens's range of focal lengths.
The tests suggested that this lens is in some ways better than the much more expensive Canon 15-85mm, especially at the longer (zoom) end. It is certainly a brighter lens. The tests suggest for example that the Canon lens has to be stopped down to f/5.6 to be equal to the Sigma at f/4.0. In additon, a helpful byproduct of having a larger maximum aperture is that the viewfinder is also a tiny bit brighter.
At f/4.0 and 17mm, I see no evidence of the edge softness that some have reported. I suppose that's one of my motivations for writing this review; I bought it in spite of what dpreview said about its characteristics at 17mm, but I've been very pleasantly surprised to see that they were dead wrong. Maybe they've improved the lens since its release over a year ago and didn't tell anyone, or maybe it works better on the 60D than on any of the cameras they tested it on, I don't know. I've looked closely at 100% views on my large high-res monitor and I don't see what they're talking about. In one photo I can read (barely) a tiny sign in the far left side of the frame at 17mm. Does that sound like "soft" edges? I see branches in the tops of trees razor sharp against the sky. But as with other lenses you must stop it down for best results. It's pretty clear that for maximum sharpness you shouldn't use this lens at any setting below f/4.0. Some commentors have complained that their pictures aren't that great when shot at widest aperture, and of course this is true because for the great majority of zoom lenses, especially those under $1000, that's just reality folks! Two exceptions to this are the new Sigma 18-35 f/1.8 and Sigma 24-105 f/4, both of which according to tests are tack sharp even at their widest aperture, but these lenses cost twice as much as this lens, and the latter is really designed for full frame cameras. (One of these lenses will probably be my next purchase, but for now the camera buying spree has to stop. My current cameras and lenses are good enough!)
The optical stabilizer works great but it does make some odd noises; whirring sounds and the occasional click. For this reason it probably wouldn't make a good video lens. I don't do video so I don't care, but if I want to make videos I already own what is probably the best DSLR for video, the Sony A77 with the 16-50mm f/2.8 kit lens.
In conclusion, I think this is the best lens I've ever owned for my Canon APS-C cameras. I'm very happy with it and I can't wait to take some more pictures with it. I've owned all of the earlier Canon kit lenses, the 18-135, the 18-55, and the 55-250, as well as a couple of Sigma lenses, but wish I had saved my money and just bought this one, but of course this lens design is quite new and its previous versions weren't quite as good, so I'm glad I waited until they got it right!