Sigma 10-20mm f/4-5.6 EX DC HSM

 
Lens Reviews / Sigma Lenses i Lab tested
10-20mm $374
average price
image of Sigma 10-20mm f/4-5.6 EX DC HSM

(From Sigma lens literature) Sigma 10-20mm f/4-5.6 EX DC HSM lens allows enjoyment of super wide-angle photography and it is a very powerful tool for indoor shooting and landscape photography with APS-C size image sensors of digital SLR cameras.

Wide angle of view (102.4 degrees at 10mm and 63.8 degrees at 20mm) offers the photographer greater freedom of expression. Three SLD glass elements are employed for effective compensation of color aberration, which is a common problem with super-wide angle lenses. One piece of glass mold and two hybrid aspherical lenses, offer excellent correction for distortion, as well as all types of aberration.

This lens is equipped with an inner focusing system, and the models which are equipped with HSM system provide quiet, high speed autofocus shooting and also offer full time manual focusing. It has a minimum focusing distance of 24cm (9.4 inches) at all focal lengths. The non-rotating lens barrel perfectly suits the petal shaped lens hood. A circular polarizing filter can also be used conveniently.

Test Notes

This lens was another sweet little surprise from Sigma, delivering true ultrawide angle to cropped-sensor DSLRs, at a very attractive price, and frankly, with better optical quality than we expected for the price.

As most are aware, one of the limitations of digital SLRs with sensors smaller than a 35mm film frame is that they capture a narrower viewing angle with any given lens than do their full-frame counterparts. This leads to what's commonly (but erroneously) referred to as a "focal length multiplier" or a "crop factor" that's typically in the range of 1.5 to 1.6x. (Cameras adhering to the 4/3 standard have crop factors of 2.0, while some of Canon's pro DSLRs have a 1.3x crop factor.) What this means is that a lens that used to be a wide angle ends up being closer to a "normal" lens: For example, a 28mm lens on a 1.6x camera takes in about the same angle of view as a 45mm lens on a 35mm camera. And that ultra wide-angle 17-35mm zoom turns into the equivalent of a 27 - 56mm.

The major camera manufacturers and some of the third-party lens makers have begun to address this issue by making ultrawide-angle lenses with reduced image circles, specifically designed to work with sub-frame DSLRs. As we've noted before, Sigma has really been leading the way with a large number of sub-frame optics, and one of their more notable achievements appears to be this 10-20mm superwide zoom. On 1.5x DSLRs like the Nikon and Sony/Minolta lines, it corresponds to a 15-30mm zoom, while on 1.6x cameras like the Canon Rebel and EOS 20/30D, it corresponds to a 16-32mm optic. I both cases, it covers a nice chunk of ultrawide territory. (Note that the image circle of this lens is most likely not large enough to adequately cover the sensor on a 1.3x camera.)

In our testing, we were pleasantly surprised by how sharp this lens was wide open, across its focal length range. It wasn't perfect, and never got really *crisp*, but on the whole did quite a bit better than we had been expecting. At the 10mm end, the center is very sharp, but the corners get a little soft, but the corner softness decreases substantially as you move toward the "tele" end of its range, or as you stop down even a little from wide open. At 10-12mm, the corners don't really flatten out until you get to f/8, and even there, they're not quite crisp. - But they're not far off, to the point that it'll probably take a bit of pixel-peeping to see the softness anywhere at f/8.

Where this lens does suffer somewhat at maximum wide angle is in the areas of chromatic aberration and light falloff ("vignetting") which were both on the high side. Actually, the maximum CA is high, while the average level is quite low. This is because the most severe CA occurs only at the extreme corners and edges of the frame, while most of the image area is quite clean. (And even in the extreme corners, the coloration from the CA isn't as strong as we've seen with some lenses.) Average CA stays quite low as you zoom from 10 to 20mm, while the maximum value decreases quite rapidly, dropping to a very low level by 14mm.

Shading or "vignetting" never gets real bad at the 10mm end, but then decreases relatively slowly as you stop down or zoom towards 20mm. The worst-case light falloff in the corners is only 0.7 EV, decreasing to just over 0.5 EV one stop down from wide open, for most focal lengths. Geometric distortion is quite interesting, in that the maximum level swings from pretty severe barrel distortion (1.3%) at 10mm to slight pincushion (0.29%) at 12mm, holding more or less constant at that level over the rest of the zoom range. What's really interesting though, is that the geometric distortion is almost entirely restricted to the very corners of the frame, so the average distortion level is actually very(!) low: Along the top and bottom of the frame, and along much of the left and right sides, the image is remarkably rectilinear. Sigma's optical engineers have done a very good job of compensating for distortion in the design of this lens!

Build quality of this lens is really quite good too, although we obviously don't have any way of determining how well the lenses we test will hold up to years of regular use. That said, the Sigma 10-20mm has a pleasant heft to it, with a very solid feel in the hand. The focus and zoom controls operate smoothly, although the zoom ring felt a little stiffer than we personally prefer. - But the zoom also showed zero tendency to "creep" when the camera was pointing straight down or up. All in all, a very nice feel to it for an affordably-priced lens, and autofocus seemed quite fast on our Canon EOS-20D test body.

Compared to the ultrawide zooms from the camera makers, the little Sigma holds up surprisingly well, particularly considering the huge cost disparity between them. Canon's 10-22mm zoom tested very well, slightly edging out the Sigma 10-22mm in places, but getting beaten slightly in others. The Canon also does better in terms of maximum CA, but average CA is quite close to that of the Sigma. Likewise, the Canon lens does better with geometric distortion over most of its range. When it comes to shading though, it's closer to a tossup, with the Sigma better at the shortest focal lengths, and the Canon better at longer ones. When you factor in the Sigma's $450-500 price against the Canon's $700-800 price, the Sigma seems to be a clear winner.

In the Nikon camp, the competition is the 12-24mm f/4 DX. This was one of the first lenses we tested, and it showed a substantial "tilt" in its sharpness characteristics. We've come to believe that this is indicative of a lens that's been subjected to mishandling (or mis-manufacturing), with one or more of its internal elements out of alignment. - We hope to re-test this in the near future (hopefully before the end of 2006). With the tilt, it's hard to say how the Nikkor 12-24 really compares to the Sigma 10-20 in terms of sharpness, but I'd hazard a guess that they're in the same ballpark, based on how the Nikkor's characteristics change as you stop it down. In other areas, the Nikon 12-24 beats the Sigma 10-20 in terms of shading ("vignetting"), chromatic aberration (over most of its aperture/focal length range, at least), and geometric distortion. Assuming that the tilt we observed in its blur characteristics was an aberration, it seems safe to say that the Nikkor is the better lens all around. - But then it should be, with its $900 - $1,000 street price almost twice that of the Sigma 10-20mm.

The bottom line seems to be that the Sigma 10-20mm f/4-5.6 EX DC HSM is a real bargain for an ultrawide zoom for sub-frame cameras. If you want to shoot really wide with your DSLR, this lens looks like a good way to go about it.

Sigma 10-20mm f/4-5.6 EX DC HSM User Reviews

8.9/10 average of 60 review(s) Build Quality 9.0/10 Image Quality 8.6/10
  • 9 out of 10 points and recommended by Niel (12 reviews)
    Cheap, lightweightish useful
    Firmware doesn't work with some bodies.

    I bought mine used having used one at work, it's usefully wide and works OK on full frame too if you crop the image you'd never know it's from a circularly limited shot, having used it instead of my 14-24mm f2.8 Nikon for holidays/travelling I know the weight and bulk saving is worthwhile. Don't get me wrong, the Nikon lens is vastly better, but who wants the weight on holiday? As I use a crop frame body as a back-up it make sense to carry the widest lens possible.

    The only downside is the Sigma/Nikon firmware doesn't work together with some bodies, though as it's mainly down to AF and I preset focus & aperture it's not really an issue.

    Bought used cheap it's a keeper!

    reviewed October 1st, 2023 (purchased for $125)
  • 9 out of 10 points and recommended by SquireSnapsalot (2 reviews)
    focal length, full time manual focus, good image quality stopped down, nice build quality
    bad wide open

    Ultrawide is my favourite range, it's so much fun, but it's also really hard to design lenses for. So, ultrawide comes with optical issues unless budget is thrown out the window, one thing the sigma 10-20 f4-5.6 is most known for is it's whacky distortion profile (but it's one click to turn on lens correction and get rid of it, don't worry about it). Wide open it's soft, vignettes a lot, and underexposes, generally max aperture should just be avoided whenever possible. Stop 'er down and she's pretty sharp.

    For some reason with this lens the focus is not super accurate on my 7D, but on the other hand you don't really need to focus at 10mm anyways especially if you're shooting at like F10.

    reviewed July 29th, 2017
  • 8 out of 10 points and recommended by miketaylor (1 reviews)
    Build, optics, internal focus
    Requires a whopping 77mm filter, aberrations at 10mm

    After seeing numerous photographs taken at wide angle for years, I've wanted an ultra wide angle lens.

    I had no idea for what I was in until I actually obtained one!

    First off, I love taking photos of sunsets and clouds.. big sky photos and displaying object scale. For this an ultrawide can get you what you want.

    However, I had no idea the amount of work involved in avoiding distortion when at the wide side of this lens (10mm)... you must be careful not to pitch up or down the camera from the subject or you will get massive image distortion! This can be played to your advantage but it can also be simply annoying too. Also close up, objects take on a slight to moderate fisheye effect almost. To really get this effect though, the lens would have to be able to focus even closer than it can.

    Also, 10mm is simply REALLY INCREDIBLY wide! This is fantastic if you are in a tight place and want to have much of the space in the image (interior shots -- especially in realty or the sort). However, outside in larger space, this means you are losing detail of your subject simply from covering more area in the field of view.

    For landscapes and such, the longer end of this lens is probably going to be the smarter option (focal length wise). Forget about Panoramas with the wider end btw. In my experiences, way too much distortion means you will have headaches getting images to properly overlap.. even with distortion correct enabled (LR user here). Plus with distortion correction enabled, means you will be removing a portion of the actual image in crop to accommodate said distortion (it can be rather severe on the edges and somewhat complex). So just use the mid to long side of this lens if you are considering panoramas or landscapes with more detail. The issue there is this Sigma 10-20mm lens tends to be softer in the mid to longer side of the focal range. I think my 18-135 might be sharper and around the same barrel distortion amount as this Sigma lens (which is rather minimal on long side of the 10-20) at 18-20mm. Also, you're getting f/5.6 on the long end of this lens.. so forget about it if you are in a low lit space with no tripod.

    I hope this review makes sense.. The lens isn't a dog.. by any means.. it is rather sharp stopped down to F/8 and F/11 but you might want to handle an Ultra wide lens before buying just to ensure this is really your cup of tea. It is the only lens where I really had to practice using it and work through the dynamics of such a particular focal range and the properties of this particular lens -- didn't come automatically.

    This is a chubby lens but it is plastic so it is lightweight. Some might find that a flaw, but I think had it been metal, this would have been a brick to hold! 77mm threads means screw-on filters are going to be expensive. I use a Cokin P series step down ring and the square filters instead. That way, I can use all of my ND filters without having to get individual ones for each thread size. Just a cheap step down ring for the filter holder (bought a ton of those step down rings on ebay for next to nothing).

    Also, this lens WILL flare in bright light sources (namely the sun!). You won't get a super awesome copy that doesn't flare. This lens flares. Expect it to and plan accordingly. If you take lots of shots with the sun visible or just off camera, and don't want to Post Process the flare effect out, look for a different lens.

    I'm glad to have this lens and will get much use out of it.. but I don't think it will be the most affixed lens on my camera as I thought it might have been before receiving it. 10mm, however, is fantastic for big sky photography, massively large landscapes (where detail isn't the leading factor), interior spaces, creative effects, and generally projecting scale of objects. I find, as a result, this Sigma 10-20mm makes up for it's limitations.

    http://www.hitsticker.com | http://www.printradiant.com | http://www.adstateagent.com

    reviewed November 2nd, 2015 (purchased for $400)
  • 9 out of 10 points and recommended by larslentz (4 reviews)
    ultra-wide

    This is a great wide angle lens for an APS-C camera. I've used it a lot in my photography of landscapes, and it is quite sharp with a nice ability to take 77mm filters. I use a polarizer on it even though it is a wide angle, and I have great results. The corners are a bit soft at the minimum focal length of 10mm, but correcting this in post production using DxO Optics Pro works for me. There is some chromatic aberration as well, but minor and correctable in post also. Overall this is a low-cost, wide lens that works well for me, and I would recommend it.

    reviewed May 23rd, 2015 (purchased for $410)
  • 9 out of 10 points and recommended by eskil (8 reviews)
    Really wide, can take filters
    Soft corners, slow AF

    10 mm is really wide. So wide that objects in the corners looks distorted even though this is a rectlinear lens. The aperture is not large enough for astroscaping, but on the other hand the DoF is so deep that it is sharp from one armlengt to infinity. Except for the corners. You have to stop it down at least one stop to get decent sharpnes in the corners.

    Even though the generous wide angle, there is still room for 77 mm filters. I frequently use a gradual-ND filter for landscape photos. Polarizing filters are not recomended as the polarisation of the sky differs too much across the frame at wide angle.

    Autofocus is a bit slow, but focusing is only needed for really close up shots. For normal landscaping, turn AF off and set focus on one meter and you are good to go.

    reviewed May 5th, 2014 (purchased for $500)
  • 9 out of 10 points and recommended by Gromit (8 reviews)
    Build, excellent IQ, price
    Soft in corners until f8

    Bought this little beauty very recently and have put upwards of 200 shots through it at a guess. Getting used to having an UWA has been loads of fun (was quite novelty to start with) and I think this lens will spend more time on my EOS 40D than my others - it's just so darn useful!

    Good: It's neatly built - not quite up to L-Series standards of course - but zoom and focus action is very smooth and well-damped. Finish is good too. It's sharp in the centre from wide open, improving markedly by f8 which is where its sweet spot lies.

    Bad: At the price? Not much really - it's soft at the corners when wide open, there's some CA present when focusing close-up. I have heard stories of variable quality between different examples - seems Sigma's QC isn't always up to scratch.

    Summary: Great value for money, nicely built and great performing lens. I'm extremely happy with mine.

    reviewed June 28th, 2013 (purchased for $450)
  • 9 out of 10 points and recommended by makcv113 (8 reviews)
    Very useful zoom range, UWA, autofocus with any body (Nikon)
    non constant aperture, slow, barrel extends a little when zooming in, no OS

    I had this lens on a few Nikon bodies that I owned, a D3100, D5000, and D90.

    The lens will AF and MF fine on both AF/non AF motor bodies, at least for the bodies that I had.

    What I love about this lens other than the fact that it's super wide, is the very useful zoom range. If you compare it to a 35mm format, it gives you 15mm at it's widest and 30mm at the tightest. I use the 20mm on the lens when I don't have my prime with me, and the 30mm equivalent for Nikon (32mm for Canon) is perfectly fine if you don't mind the slow aperture that real primes don't have.

    Build quality feels strong, but doesn't give the excuse to abuse it. Autofocus speed was fine with me, I didn't need something super fast. Great for the street if you don't need anything longer than 20mm. When I did, I used my 35mm 1.8G for the 52mm equivalent.

    I recommend this lens for the zoom range. The other lens I'd also recommend is the Tokina 12-24mm for the zoom range also. I don't like the Tamron 11-18mm or the Tokina 11-16mm (unless you need the speed).

    Some sample photos taken attached to either a D90, D3100, or D5000:

    http://flic.kr/p/c7d4Vw
    http://flic.kr/p/csT415
    http://flic.kr/p/cqK1tC
    http://flic.kr/p/c7deEJ
    http://flic.kr/p/crSbnj

    This was taken with the lens but cropped:
    http://flic.kr/p/ckE8dj
    http://flic.kr/p/cnFntS

    Here's my set of the lens:
    http://www.flickr.com/photos/mlaphotography/sets/72157629978341842/

    reviewed August 19th, 2012 (purchased for $375)
  • 9 out of 10 points and recommended by bftucker (1 reviews)
    Price, build quality, image quality, fast focus and quiet.
    Could be a little faster. Not uasble on full frame bodies.

    I am using this lens on a Canon 7D.
    Price wise this is a good value.
    The lens is sharper than I expected.
    I can get great images even at 1/60 second.
    Easy lens correction in Lightroom 3.

    reviewed November 20th, 2011 (purchased for $550)
  • 9 out of 10 points and recommended by dda (13 reviews)
    price / build quality / ease of use

    Needed a cheap wide angle (don't use this type of lens a lot as I have the nikon 16-85) - love it and ... still don't use it enough LOL

    reviewed July 18th, 2011 (purchased for $350)
  • 7 out of 10 points and recommended by scooby (3 reviews)
    great focal range
    unreliable results

    I really don't like this lens much, it could just be my copy, but I find the results hit and miss. It is capable of superb images but I find focus and exposure can be really off at times (many times). I read somewhere that it is hard to focus because of pronounced field curvature..maybe thats it. I thought I had a bad copy, but after many photos, I think it's just the way the lens is designed. I much prefer my older, clunky Tamron 11-18, believe it or not, it's much more consistent.

    reviewed June 18th, 2011
  • 9 out of 10 points and recommended by ReverendOlaf (3 reviews)
    Awesome value and insanely wide
    Once you get the wide angle bug, you'll never shake it

    I was scared to let this lens go (to "upgrade" to the 10-20mm f/3.5), and I still miss it. Granted my f/3.5 lens is just as good, but it's not better (save for having some aperture choices this one lacks).

    10mm is crazy wide, and not only does this lens go there, it's quite adept at doing so. Wide open it's sharp in the center, and stopped down a bit (not a huge deal, since a relatively slow shutter is possible at 10mm) it's wonderful. I typically shot at between f/8 & f/11, but I never found shots taken at f/5.6 objectionable. CA and distortion are no worse than average, and frankly neither are an issue for my uses. Build quality is top notch, and the 77mm filters aren't so bad (I often used a grad ND on this bad boy).

    D40/D5000/D3100 users note that the Nikon version does not have the AF switch you see in the photo, which isn't an issue with bodies with an AF motor (thus an AF switch), but will make full time MF impossible. You can still override things.

    If you're interested in dabbling in ultra wide angle lenses, this is the lens to get if you have a cropped sensor camera.

    reviewed December 19th, 2010 (purchased for $475)
  • 10 out of 10 points and recommended by grule (7 reviews)
    Range (esp 10mm),build
    none to speak of at this price

    It's all been said.A great lens for the money.

    reviewed December 11th, 2010 (purchased for $400)
  • 9 out of 10 points and recommended by Nikonuser (5 reviews)
    Sharp, well built, price
    not yet

    I own this lens for about 1 year and I have used it for landscape and night shooting last winter. I have had very good results.

    reviewed November 7th, 2010 (purchased for $600)
  • 10 out of 10 points and recommended by mannypr (3 reviews)
    Sharp , Built , fast in focusing , colors
    Distortion at wide 10mm

    I didn't give this lens a 10 for image quality because I know there are better lens out there in the market but taking into consideration the price it's image quality is a super 10+ . It's very nicely built and looks expensive . It's HMS motor is virtually silent in operation and fast with good accuracy . Color rendition is very nice with good and gradual tonal transition . My copy of this lens is extremely sharp from 10mm to 20mm. It's borders are sharp also with just a bit of softness at edges only seen when you go 100% . At normal viewing it's almost invisible. This is a fantastic lens at a more fantastic price and it's the lens that most fun has given me . The perspective and aparent DOF this lens gives is awesome . If I would have to say something negative in it is that at 10 mm it has just a bit of distortion at the corners but if you learn to level it in shots the distortion dissapears . For the price this is a no brainer...Highly recommended.

    reviewed November 6th, 2010 (purchased for $439)
  • 7 out of 10 points and recommended by omega6666 (1 reviews)
    The one I found in the end is pretty sharp, though never really crisp, but symmetrical. Love the feel of the focus and zoom rings. Love the easily adjustable AF/M switch. Includes hood and pouch. Great price compared to roughly equal Canon 10-22.
    main con is soft on edges when fully open and asymmetrical unsharpness and CA for many bad copies.

    I've seen enough great results of this lens on the internet, but I've tried 2 copies so far, which all had an unsharp/stretched/bad CA blur on one side of the image. Different sides with each one.

    I've let them send the first one back to Sigma. I've read some reviewer sending the best of 5 to Sigma, and coming back as the worst of them, so I''m not really enjoying this whole experience.

    Paying this much should give me something I should be really happy about. I'm not planning on settling for less, especially when knowing how good this one CAN be... :/

    [edit:]I've received the 3rd one after 1.5 months of waiting while it was at Sigma repair center. This one's GREAT! I'm sooooo happy. Thank god I persisted...

    reviewed February 5th, 2010 (purchased for $565)
  • 10 out of 10 points and recommended by dadgummit (6 reviews)
    Sharp wide open, Fast AF, Inexpensive
    The desire to try more expensive lenses before purchasing this.

    Just goes to show you…….

    I first tried the Sigma 10-20 f3.5 and found it waaaaaaaaaaaaaay too soft wide open and hated the huge plastic ring extending out past the diameter of the lens so it went back. I then tried the Tokina 11-16 that everyone raves about. My first copy front focused and the second one was too soft at F2.8. The third copy was sharp but the AF motor was too slow to capture good shots of a running toddler so it was sold.

    I was going to give up but then decided to take one last shot and ordered the Sigma 10-20 F4 (the old version). All I have to say is WOW this is the lens I was waiting for!! It is sharp wide open, it is sharper stopped down, the HSM motor is lightning fast.

    I can honestly say that this lens gets sharper pictures at lower apertures than the newer “faster” sigma. The f3.5 sigma is no good until about f5.6 where the old version is good wide open at f4.

    If either of the first two lenses were this good I would have kept them but I am glad they were not because this lens cost about $250 less. I guess it goes to show that you do not always get more when you pay more.

    reviewed October 30th, 2009 (purchased for $400)
  • 10 out of 10 points and recommended by jeremiah (3 reviews)
    great price, fun to use, wonderful build quality, fast & quiet AF
    slow - not the best for indoor, night-time use.

    Wonderful lens. I didn't want to spend too much for the wide-angle so I bought third-party. No regrets at all.

    Distortion is fairly correctable with PS and the images are wonderfully saturated and contrasty.

    Only wish it was the f/3.5, but as I wasn't willing to pay that much (more than double the price I paid for this lens), I'm really satisfied.

    Just all around great lens that's really fun and challenging to try to capture the world with.

    reviewed August 16th, 2009 (purchased for $360)
  • 9 out of 10 points and recommended by PeteD (12 reviews)
    good build quality, value
    the corners

    This is capable of taking some fun photos, you just have to learn its foibles

    reviewed March 13th, 2009 (purchased for $450)
  • 9 out of 10 points and recommended by jamesm007 (7 reviews)
    Wide! 10mm versus 11mm or 12 is a big differance, great IQ, low CA/PF, low barrel, low cost
    A tad soft at 10mm/f4 in the deep corners; vignetting could be a bit better

    Using this for my Samsung GX10 (Pentax K10 brother).

    Update: Aug, 13, 2014
    A bit over five years use and it looks new and performs new. Now on the GX10, K20D, and K-5 Pentax dSLRs. I still shoot with the K20D and K-5. The lens is holding up to the increased resolution with strong color, contrast and rewarding fine detail, its a sharp lens for sure. I do keep this lens in its pouch given in the box. This lens is still produced and sold by Sigma. The reason I am updating the review. And its selling for much less than what I paid. Its a compelling offering. This Sigma 10-20mm f/4-5.6 EX DC lens is a steal. Perhaps there are UWA lens as sharp, or a bit sharper (pixel peeping) But at more cost! IMHO this lens is good enough at f/8 to make most photographers happy; including pros. Its build is solid, feels top notch, being a EX lens it should. The review by SLRgear says it all.

    Lens at this level are really hard to beat. Because it does not produce visible distortions, aberrations, and is contrast, sharp and colorful.

    All below still applies but now its also a bargain. Get a new one while you can!



    My first impression was Wow! I was happy. For some reason I expected some distortion being so wide like fisheye or something. But thats what struck me first, how wide and flat the image was at 10mm and how sharp,also great contrast and color. I put the IQ a little above the Sigma 17-70mm. The pics just look better, could be because its using 3 ED elements and 3 aspherical elements and this gives the Sigma great IQ and does make this lens a true EX pro quality lens.

    Some lens may review a bit better but remember they probably start at 12mm, which is much smaller than 10mm, not a slight difference, a large difference. I calculated you get ~65% more total image area over a 12mm at 10mm. From 12mm-20mm this lens is almost perfect wide open, nothing to complain (Oh a bit of vignetting maybe). At 10mm/f4 the deep corners are border line, a tad soft, not too bad.

    You may see some reviews saying this lens has high barrel at 10mm, not totally true. For 98% of the frame & 10mm its flat as a board (read SLRgear review) - shockingly so at first, only as slrgear says the side and very deep corners have some barrel at 10mm, its quickly and perfectly eliminated with PTlens.

    I guess this review is sounding very positive. But I am considering price as well. There's a few wide angle lens out there most start at 12mm, a couple at 10mm. Now for the price your getting 10mm, that's wide! Also EX quality, this lens feels high quality and seems built to last. In the USA Sigma EX lens come with an extended 3 years of warranty for a total of 4 years. When Sigma puts EX on their lens, they back it up.

    I honestly cant think of anything that should be considered as a con, enough of a con to stop someone from buying this lens, who wants a wide angle for an APS sensor at this price, really this lens competes with the best of them, so I should say any price.

    Cons, would be, no weather sealing, no AF motor for Pentax brands. But this may not be a con as it focuses lightening fast with screw drive. Could be brighter/faster.

    reviewed February 2nd, 2009 (purchased for $500)
  • 10 out of 10 points and recommended by xiod (2 reviews)
    compact, sharp, excellent price/quality, very low CA, fine geometry, very fast AF
    don't likes direct sun

    best super wideangle lens for cropped sensors, much better than tamron\tokina, has HSM suitable for Nikon D40\40X\60, great usability, nice EX look (as for me =)
    not expected this wideangle lens to be so sharp

    reviewed January 23rd, 2009 (purchased for $430)
  • 9 out of 10 points and recommended by photographybyajit (4 reviews)
    Price; Build Quality; Fast & Silent Autofocus
    Sharpness; lots of barrel distortion

    This low priced ultra wide angle zoom lens from sigma is well built and feels solid.
    Considered a good travel lens, but I would purely prefer using it for shooting landscapes.
    The sweet spot I found was at 16mm-f8, otherwise overall the image quality is a little soft, but when shooting landscapes it is negligible.
    If your subjects are too close when shooting at 10mm, then expect a lot of barrel distortion, but I am sure there could be many creative advantages.
    Like to share some shots I took from my recently bought Sigma 10-20 f4-5.6 for my Canon XTi.
    http://www.photographybyajit.com/Outdoor/slides/APS081117038.html
    http://www.photographybyajit.com/Outdoor/slides/APS081117072.html
    http://www.photographybyajit.com/Outdoor/slides/APS081117048.html
    http://www.photographybyajit.com/Outdoor/slides/APS081117076.html

    Happy Shooting!
    Ajit Pal Singh.

    reviewed January 17th, 2009 (purchased for $500)
  • 8 out of 10 points and recommended by swintonphoto (4 reviews)
    Great price, excellent build quality, affordable price, good autofocus, handles distortions well.
    Slightly soft in corners at wider apertures

    I have been very pleased with this lens. It is extremely wide, and works very well on my Olympus DSLR. It's build quality is fantastic for the price point. I am very pleased with the image quality. The only weakness I have had with this lens is slightly soft corners and inconsistent contrast control in the corners. Both of these problems seem to only occur at the widest setting (10mm). However, it is minor. I would buy this lens again.

    reviewed November 22nd, 2008 (purchased for $550)
  • 7 out of 10 points and recommended by sflorio (8 reviews)
    Super-wide, good focus
    Soft 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.
    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:
    http://farm4.static.flickr.com/3029/2850881878_1fc73df7b3_b.jpg
    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.

    reviewed September 12th, 2008 (purchased for $500)
  • 8 out of 10 points and recommended by gsmith (1 reviews)
    very wide, inexpensive compared to there superwides, great handling, filter thread
    heavy, bad sunstars

    First off the focal length of this lens is great. The build quality is quite good, I really like the stiff feel of the focus and zoom rings. It would be nice if the focus ring was even stiffer though, in my opinion. This lens is fairly heavy, though not too big. The weight gives great handling but makes it a bit for cumbersome to carry around

    Optically this lens is capable of good, but not incredible images. Stopped down to f/11 it is good enough, but the corners are not stellar. According to review it has some weird uncorrectable distortion at 10 mm. I haven't shot any images to test this so I can't confirm or deny that.

    The two biggest advantages of this lens in my opinion are focal length (10 mm is great) and price (this lens is the cheapest APS-C super wideangle).

    reviewed September 6th, 2008 (purchased for $569)
  • 8 out of 10 points and recommended by Rover (13 reviews)
    wide as hell, good IQ,
    slow max aperture at tele

    I didn't own this lens, just borrowed it from a friend for a business trip because I knew that 17-55 was going to be too narrow for that occasion. And what a trip this was...
    This lens turned out excellent and I soon got addicted. With an UWA like this you can get shots you never thought were possible. It was decent even for indoor shots despite its rather slow and variable maximum aperture (4-5.6). All in all, a really good choice.

    Long story short, eventually I got myself a Tokina 12-24 instead but I still remember this one fondly. Unless you hit a bad sample (it's a Sigma after all) you'll have a lot of fun.

    reviewed July 28th, 2008
  • 10 out of 10 points and recommended by aesace (2 reviews)
    build quality, sharp, wide, low CA
    on pentax no HSM, not available the MF while in AF mode

    As I bought this lens to my Pentax K10D, I was surprised by the sharpness. It's better than the manual prime lens I own. The color reproduction is great on this lense. With the low amount of CA I'm also very pleased. The focussing is quite quick and exact.

    However, the Pentax version doesn't have the HSM motor and you cannot use the MF ring while in AF mode.

    Generally for the price I gave for it, this is really a great value youl'll get and actually till now it's the best lense I own.

    reviewed July 23rd, 2008 (purchased for $470)
  • 9 out of 10 points and recommended by wesfoto (5 reviews)
    cost, coverage, quality
    none, for what it is

    If you need a useful, really wide angle lens for your APS-C camera, the price and features on this lens are impossible to beat. I shoot a lot of close up shots with this, and the fact that it supports enhanced TTL (or whatever name your camera maker decided to call it) comes in very handy. I always keep this lens handy.

    reviewed July 7th, 2008 (purchased for $400)
  • 10 out of 10 points and recommended by eLLeRoId (2 reviews)
    HSM, sharp, kinda cheap for its price

    just bought this lens and tested out a couple of shots and it's very sharp, no CA and the distortion is just fun to play with.. it gives a whole new perspective on pictures i shoot.. definitely recommended

    reviewed June 29th, 2008 (purchased for $570)
  • 9 out of 10 points and recommended by HighSierra (13 reviews)
    Supreme rectilinear width, sharp and colorful, low CA and distortion, HSM
    Slow max aperture

    I've been extremely happy with this lens. Overall image quality leaves very little to be desired, especially when used at F8, where max sharpness is only lost in the extreme corners at 10mm. At 12mm and higher, distortion isn't an issue, and CA has never been significant enough to merit correction for me.

    I picked this lens because it has the widest angle of view, and closest focus capabilities of the current crop of DX ultrawides, and it has not disappointed in either regard.

    If I could change anything about this lens, I'd make the maximum aperture faster. But considering all of the positives about this lens, it is tough to consider that a con, since after all, you can't have everything.

    The build quality is very nice without being overly heavy, just very solid. The outside finish looks nice and professional. HSM focusing is just as quiet and quick as Nikon AFS.

    Unless one really needs the F/2.8 of the Tokina 11-16 or Nikon 14-24 lenses, the Sigma offers a unique package of characteristics in the best value in ultrawides at this time.

    reviewed June 14th, 2008 (purchased for $460)
  • 9 out of 10 points and recommended by megafranz (2 reviews)
    Image quality, price, well build
    uhmmm, didn't like the the printquality of the black box it came in

    !!WAW!!
    a big bang for the buck

    Looking for a resanoble priced ultra wide lens I was
    this sigma 10-20 and the Tamron 11-18, But desided t go for the some more expansive Sigma, because I think the Yamron would let mee down. His glorry days where in the 8mp age so I was afraid that it could not perform at 14mp. Hewre in Holland the Tamron is cheap, but the price is forgotten, the quality remains.

    When stopped down to 5.6-11, I like the IQ a lot, sharp, little distortion and CA, easy adjustable with LR PS and PTLens.
    I only have the impression that is is not as sharp as my Tamron 17-50. But that is mayby due to the magnofication of the details.

    I especialy like wide angle photography and what a fun lens this is for architectural and landscape photograpy.
    I have now idea how this lens compares to the Canon's and Nikons, but I don't think there is a big difference, so I can recommend this one to any none pro.

    reviewed May 17th, 2008 (purchased for $500)
  • 9 out of 10 points and recommended by grahambo (8 reviews)
    sharp, CA resistant, Flare resistant, 10mm
    corner distortion, cool color rendition

    I borrowed one of these for a friend when I went on a trip last year. I waffled around on which wide angle lens to get for a while, but when I went back through the pictures I took, I realized the 10mm really made a difference. The lens is not perfect, but for my purposes I am happy with it.

    Sharpness and contrast are good. Not perfect, but good enough. Color is a little bit cool. I consistently need to warm pictures from this lens in post processing (Capture NX makes this really easy).

    Distortion is noticeable in the right situations, but does not show up in my landscape photography. Distortion seems confined to the corners, so if I crop a 2:1 from the middle of a picture, the distortion is almost completely removed.

    On other bizarre effect of 10mm is that dust on the front of the lens is not defocused. I need to check the lens for specks every time I take the cap off.

    Picures with the 10-20mm on my photoblog: www.photograhambo.com/index.php?x=browse&category=22

    reviewed February 24th, 2008 (purchased for $470)
  • 10 out of 10 points and recommended by EdgyPhoto (3 reviews)
    WIDE and BRIGHT

    First thing out of the box I noticed is that it's a stout little lens. Solid and sturdy build, firm (but not too firm, aka not STIFF) zoom action. Numbers on zoom ring are accurate - did a test and exif shows exactly same as numbers on ring (if that's important!). Focuses quick, though ironically not the quitest motor, even though it is HSM. Will hunt in very low light and against non-patterned subjects - I do a lot of real estate photography with this lens and it needs SOMETHING to focus on (or maybe that's the body!) Shooting with Nikon D200.

    LOVE using this lens for my real estate photography. It's rectilinear, no odd curvatures (no fisheye effect) though it certainly does stretch things as you get closer to the edges, but that's the nature of 10mm (15mm equiv on D200). Pay attention to the location of camera and angle you're shooting at and the pics come out great - samples at http://www.EdgyPhoto.com in the galleries - almost ALL of the real estate gallery shot with the 10-20.

    I've noticed that despite the "non-slow" aperture rating, it will shoot faster than my 18-135 when shooting the wide shots - guess it's got more coverage and pulls in more light.

    All in all, very happy with the lens and PAID for itself with the usage when doing real estate photography. Awesome with landscapes and nature as well. Is actually a bit difficult to use when shooting panoramas because of the edge distortions, especially when in the 10mm range.

    Haven't owned or extensively used the other ultra-wide zooms out there (only test shots) but having the extra 2-4mm on the wide side out to 10mm serves me well. I already have down to 18 so didn't want something that half overlapped that, wanted the width of coverage.

    EricB

    reviewed December 29th, 2007 (purchased for $499)
  • 10 out of 10 points and recommended by zoomfreak (9 reviews)
    superb resolution, super accurate AF , fast HSM focus, well built.
    a bit pronounced CA in high contrast area

    a great lens, my copy is extremely sharp , maybe as sharp as my EF-S10-22 , and a bit less sharp than my EF-S17-55f2.8IS.

    I think this lens is much sharper than my Tokina 12-24 and 17-40L, both of which are replaced by this lens.

    this is the only one lens from third party that I love and keeping in my kit.

    reviewed December 8th, 2007 (purchased for $450)
  • 9 out of 10 points and recommended by Nikola_Konsulov (10 reviews)
    Great wide-angle zoom range, good aperture range (f4-5.6), can produce sharp images, fast auto focus. Makes great panorama pictures.
    The obvious barrel distortion for wide-angle zooms such as this.

    This lens is great. It has a desired wide-angle zoom range for the APS-C sensor. Colors and contrast are great if not excellent. Sharpness is good if not great. There is barrel distortion on the wide end (10-11mm in particular), but that is to be expected. It handles well though when you use it as intended (landscape panoramas in particular). When it comes to cityscapes it works well also. However, with individual buildings or close range objects distortion comes into play. The more closed in the lens is the more distortion you'll have to deal with. Depending on what you are shooting distortion can be an issue. Adobe Photoshop helps to take care of these problems, but not everything can be fixed with software. The build of the lens is truely Sigma EX. The zoom ring is well dampened and feels good. The focus ring is well dampened and feels good. The zoom does not creep at all whatsoever so no zoom lock is needed. Auto focus is very fast on my Konica-Minolta Maxxum 5D and my version is non-HSM. It has a 77mm thread so I can use filters; I like that. Many other extreme wide-angle lenses do not offer that possibility.

    If you need a wide-angle lens with excellent quality this lens is one to look at. It will also save you quite a few dollars as opposed to getting a first party lens from Sony/Minolta, Nikon, Canon or Pentax.

    reviewed October 17th, 2007 (purchased for $489)
  • 10 out of 10 points and recommended by EF-S10-22 (19 reviews)
    excellent resolution figures and excellent contrst details, excellent color rendition
    a bit severe distortion compared to my Canon eF-S10-22.

    At the new BKK airport , I was not careful enough , guess , and one of 2 my camera bags was stolen , I lost my most used lens the 10-22 Canon.

    I tried to replace it with the same lens but as my in Bangkok did not have it at the time , I treid the Sigma as he suggested since it was 270 US cheaper than the Canon.

    I was shocked the Sigma is sharp , nice, a little lens.

    The Distortion is as Ken Rockwell says a bit complicated and tough to correct even with the DXO or PT lens, but I seldom shoot indoor or stock stuff so , it is ok for my needs.

    The 10-22 Canon is a bit better lens over all for sure , better color rendition , better CA control , better distortion figure and better size , oh most importantly the Canon is very resistant to flare , but the Sigma is good enough.........

    As for pure resolution , I think the Sigma is sharper through all focal range , I also have had the Nikon 12-24 on my Nikon D40x (my travel light camera), the Sigma beats the both Nikon and Canon in resolution test .

    So if you are looking for a sharp HSM UWA lens , then it is a good choice as long as you do not shoot in door or architectural stuff , buildings or like that.

    I highly recommend it but I will buy the 10-22 again because of its lesser distortion at 10mm and its flare performance.

    reviewed September 28th, 2007 (purchased for $450)
  • 10 out of 10 points and recommended by Artman57 (6 reviews)
    Excellent image and build quality for the price. Sharpness overall
    None so far

    I am a Nikkor lens user for 35 years and it took me almost 6 months to decide wether to buy this Sigma, the Tokina 12-24 or the Nikon 12-24. I was decided for the Sigma mainly for the 3mm difference in the shortest focal length compared with the other two - and 3mm at the shortest focal length is something to take in consideration, at least for myself. The Nikon was very early discarded from the competition as its price is way out of my boundaries, and the Tokina because its sensitiveness to flare. So, first things first.

    1 - The build quality of the Sigma is really good. Sturdy, not excessively heavy nor light, it gives a very good balance with the D200. Focus is silent and precise, zoom ring very well damped, its a pleasure to work with it. With a protective filter in front - in my case an UV - the lens cap, although a bit flimsy, is easily handled in and out with the lens hood in its place. really. From my side, I have no problems although it could be a better lens cap. I have compared the "outer" construction with the Nikkor and I really prefer the Sigma, which is only surpassed by the Tokina at the expense of an higher weight.

    2 - Image quality " in the field " - that's what matters - is really and surprisingly very good to excellent at any aperture - being that at f/8 is really outstanding - or focal length, across all the frame. This is what gave me the biggest surprise. This lens is really sharp. The distortions are very well controled - it has the normal distortions for a 10-20 mm focal lens but it behaves even better than I expected and compared ie with the Tokina 12-24, it wins hands down - being that from 14 to 20 mm I can notice a slight pincushion distortion. Neverteless, everything is well corrected with PTLens. So no problem. For "normal" shooting, camera balance it is a must but we can dare to be more radical and get excellent "radical" compos. Colour rendition is very good - although my work is 98% black and white. Flare control is amazing. I can shoot with the sun in front of me without getting any flare at all. I am impressed.

    I was a little affraid on what concerns the problems some users got with their first sample having some image issues due to some bad centering of the lens elements. It seems I got a very good sample of this baby and it seems that those problems are solved for good nowadays.

    For the time being, its the Sigma that is attached most of the time to my D200. It's an hell of an excellent performer.

    I am really pleased with my decision and I do not regret it at all. I only can recommend it with the highest rating. If you're looking for a really wide zoom lens at a bargain price, look no further

    You can check some captures at : http://www.greytata.com/Albuns%20Porfolio/10-20/index.html

    reviewed August 1st, 2007 (purchased for $653)
  • 10 out of 10 points and recommended by SETI (20 reviews)
    Great image quality, close and fast focusing, really wide angle, bargain price
    distorsions

    First wide-zoom was Tokina 12-24. I didn't like it because of great CA and awfull corner softness. So I got Nikkor 12-24. That was good in distorsions but had soft spot in right side at 12-18mm. I changed it and new one had soft right/down corner. So I gave it back and bought Sigma 10-20. The photo quality is REALLY same like Nikkor and better than Tokina. Wider angle, good built, close focusing and very nice color rendition. Distorsions and vignetting are not a problem for my Photoshop =)

    reviewed July 16th, 2007 (purchased for $600)
  • 10 out of 10 points and recommended by spuelijah (9 reviews)
    super wide, up-close and fast focusing, sharp
    strange distortion

    This is my favorite lens! Opens up a whole world of creativity being so wide and being able to focus very close and fast.

    The only major negative I've found in all my shots were really bad edge distortion & softness when taking vertical full length portraits. Faces get extremely elongated. Build quality is not the same as a Nikon, but neither is the price!

    reviewed July 9th, 2007 (purchased for $400)
  • 9 out of 10 points and recommended by rainerknappe (24 reviews)
    very wide and good center-resolution
    heavy distortion and cornershading

    In the beginning I wasn´t so amazed with this lens. I bought the 10-20 with a Canon-mount. In comparation wit the Tokina PRO 12-24 it didn´t show the same results (more cornerdistorsion and strong vignetting). So I sold it! Later I bought it again (this time with the Pentax-K-mount). Together with the Pentax K 10 it shows brillant results (fantastic colour, good sharpness, very good contrast). If you can live with the strong cornershading (even more hefty with the K 10) and using this as a creative appearence, you will have the ultimative landscape lens!
    99% recommended!

    reviewed May 20th, 2007 (purchased for $490)
  • 9 out of 10 points and recommended by hitendra (11 reviews)
    Superb image quality at bargain price.
    77 filter size. Lens cap.

    Check out image quality here
    http://www.hitendrasinkar.com/photoblog/index.php?x=browse&category=23&pagenum=1

    reviewed April 17th, 2007 (purchased for $539)
  • 8 out of 10 points and recommended by lajos (7 reviews)
    ultrawide is fun; relatively small
    first one was faulty; heavy distortion

    I never thought I'd use an ultrawide lens this often. Even playing around with the heavy distortion at the sides is fun.

    This is a heavy lens for its size, but it's built like a tank.

    My first copy had a widely reported fault: the right side of the pictures was horribly blurred. The second copy is fine. So check the image quality before you buy. If you get a good one you will love this lens.

    reviewed January 14th, 2007
  • 9 out of 10 points and recommended by adobo (17 reviews)
    A bit cheaper than Canon's offering.. I like the built..
    Slower max aperture, zoom ring turns the other way compared to Canon's

    I'm a Canon shooter so i'm comparing this to Canon's 10-22..

    Bout this lens: its has a nice built (at least for me), good optics (Canon performs a little bit better), cheaper but you don't lose that much value..

    My only gripe is that in the second-hand market, the price of this lens is easly beaten by 2nd hand EF-S 10-22 (still in their prime quality)..

    Fun lens but you need to first learn how to use wide angles before you can maximise its capabilities.. :)

    Shoot a lot, if you notice that you want wider angles, then this lens is for you!

    reviewed January 14th, 2007 (purchased for $550)
  • 8 out of 10 points and recommended by ychen (5 reviews)
    excellent build, starts at 10mm, not pricy, a "creative" lens
    loses sharpness below f8, crappy lens cover.

    a very creative lens. one can really get interesting compositions with such wide lens. its not the sharpest i have, but its very good for its main uses.

    i use it a lot because it does give a sense of "more" to outdoor scenes. when you feel you dont manage to get the right "be there" in your outdoor shots then you know u need an ultra wide.

    its on of the cheapest of the ultrawide but its got enouge quality to satisfy most.

    f8 sweet spot.

    reviewed January 8th, 2007 (purchased for $500)
  • 9 out of 10 points and recommended by amelo14 (10 reviews)
    Cost, build, image quality, opens up a new world.
    Slightly slower than Canon counterpart, some variation in copies, Sigma caps!

    Once you see through an ultra wide angle lens you perceive things anew. The advantage of this Sigma lies in its lower cost and very good overall performance. Stopped down it allows for corner to corner sharpness. Even though it has some distortion at 10mm it is small and easily fixed. The build guarantees it will last for many years, providing a unique perspective on things.

    For a very good guide on how to use an ultra wide angle lens see:

    http://www.prime-junta.net/pont/How_to/m_Mastering_Wide-Angle/m_Mastering_Wide-Angle.html

    reviewed January 7th, 2007 (purchased for $550)
  • 8 out of 10 points and recommended by bfischer (15 reviews)
    wide, sharp, very low CA, flare resistance, near limit
    ugly distortion, slow (aperture), AF problems, ugly aperture highlights

    This ultra wide lens is usable on 1.5-crop DSLRs only. It is the widest rectlinear lens for my D200 -- 10mm vs 12mm resembles a huge difference.

    The lens delivers sharp images from corner to corner when stopped down about 2 stops. But it is slightly less sharp than the Tokina 12-24 or the Nikkor 12-24, but only pixel peepers will observe this. It's strengths are virtually no CA and very good resistance to flare. The near limit is excellent for this focal length.

    On the down side there is the signature of distortion, which I do not like at all. While the center part of the image is almost free of any distortion the border areas are afflicted by hefty barrel distortion. This signature makes it very difficult to correct in PhotoShop. Although the lens is HSM equipped, the AF hunts quite a lot on my D200 even in non-critical light conditions.

    If you like ultra wide perspectives and you can live with the distortion signature and the small aperture you should give it a try.

    reviewed January 2nd, 2007
  • 9 out of 10 points and recommended by Ross_Alford (36 reviews)
    Ultrawide angle, very sharp except in absolute far corners, good contrast
    blurry in extreme corners and lots of CA (but correctable) at 10mm

    This is an amazingly good lens. I have owned a number of other Sigma lenses, and have had pretty variable experiences with them; some great, some so-so. I have been pretty happy for a while now with a 12-24 Nikkor as my main wideangle, but have had an eye on this lens for some time, as the difference between an 18mm equivalent on the Nikkor and a 15mm equivalent on this lens is significant.

    Now that I have given this lens a good tryout, I may well end up putting the Nikkor up for sale. The extra wideangle ability is definitely worthwhile. The resolution of the lens is good enough to keep up with the sensor on my D2x, and it is consistently sharp across the frame, top to bottom and edge to edge. There may be a slight loss of sharpnes at the edges wide open, but I almost always shoot at about f/8, so that isn't a worry, and it is so slight I'm not sure if it is there. I compared it directly to the Nikkor in a couple of series of test shots, and I cannot tell the difference in sharpness or contrast in most respects. This lens does seem to produce slighly warmer images, but only slightly.

    It does have 3 failings:

    1. the absolute corners of images taken at the widest settings are sometimes not as sharp as they could be. this only applies to about 5% or less in from the corners, and about half of it disappears if you use a tool like PTlens to correct for the slight barrel distortion the lens exhibits, since that crops out the extreme corners anyway.

    2. It sometimes has lots of CA, at least with the D2x, at the widest settings. Sometimes it seems very free of CA. I have not worked out what causes the difference--it may be an interaction with some filters. At any rate, CA can be corrected when loading raw images, or using PTlens even on jpegs, and so isn't really a problem if you don't mind fixing it. Might be more of a problem if you like to shoot direct to JPEG with no post-processing.

    3. It has substantially more vignetting than the 12-24 Nikkor at the wide end. Not enough to be really obtrusive, and again easily corrected in Photoshop.

    All in all, I like this well enough that I suspect I will end up with it as my usual ultrawide angle lens. Any tiny advantages the Nikkor has are negated by the ability of this lens to get really stunningly wide perspectives. If I was starting over, I'd buy this lens without a second thought.

    By the way, construction quality seems fine to me. I like the slightly rough finish. Auofocus accuracy may well be off, as I find it often is with extreme wideangle lenses. I find with most really wideangles that the focus mechanism tends to "hunt" if you focus repeatedly, a sure sign that the camera just can't decide what the point of best sharpness is. I so far have used it mostly on manual focus, just close it down to f/8 or 11 and set focus to between 3 feet and infinity and pretty much everything is in focus anyway.

    Sample images:
    http://www.pbase.com/northqueenslandphotos/image/77778943
    http://www.pbase.com/northqueenslandphotos/image/72292261
    http://www.pbase.com/northqueenslandphotos/image/78102162
    http://www.pbase.com/northqueenslandphotos/image/77981217

    reviewed January 1st, 2007 (purchased for $500)
  • 9 out of 10 points and recommended by placenamehere (5 reviews)
    image quality, low ca, wide, padded case
    caps leave lots to be desired

    Really digging this lens for outdoor use. Light enough to not worry about carrying around and the image quality doesn't leave much to desire. I didn't agonize over this vs. the other offerings out there like I've read others tend to as I was persuaded by an unusually good price, but there's nothing making me regret the impulse buy.

    reviewed December 26th, 2006
  • 9 out of 10 points and recommended by aryko (9 reviews)
    Crisp, clear lens with great range, and value for money.
    Vignettes with regular filters.

    If you're wondering whether the Nikkor 12-24 is worth the extra money, it probably is; however, I've been very impressed with the Sigma, and feel very satisfied with it for what I paid.

    It's light, but feels solid and robust. The filter mount is metal and the lens is textured for easy handling. There's no aperture ring however so you have to use a body with Aperture controls; older bodies will fix the lens at f/22. Best to bring your exposure tables or do some mental arithmetic. That said, it's fun as heck to work on film with this lens, where at 10mm it gives a circular vignette on the sides; at 14mm the vignetting disappears.

    I've found this lens to be surprisingly sharp, even wide open (then again, your field of view is so wide it's hard to distinguish many small details). On blue skies you are rewarded with nicely saturated colours and a pleasant contrasty look. What this lens does with big open skies and puffy clouds takes your breath away (I suppose any lens this wide will do that, but it's the only one I've got).

    As the primary use of this lens will probably be landscapes, people will gravitate to polarizing filters: be sure to invest in a thin version, as regular filters will vignette until 12mm. Same with the polarizing filter on the Cokin P system, which I use.

    The lens required a firmware update to operate correctly with my D200 (AF-on button wouldn't work) which was done at my local service centre (Gentec in Toronto, Canada) for free. As well, I hear an intermittant whine when focussing (which, of course, I couldn't reproduce for the Gentec guys) which they described as operating within parameters.

    Otherwise, I'm pleased with this lens, and it's on my camera easily 50% of the time.

    reviewed December 26th, 2006 (purchased for $450)
  • 9 out of 10 points and recommended by Solutionsetcetera (5 reviews)
    Build quality, ultrawide, sharp, great CA control.
    Fat (doesn't fit in any of my lens cases), 77mm filters expensive, nothing to speak of really.

    This is my third Sigma lens, and by far the newest model I own. I am continually impressed with the Sigma design and build quality, and more importantly the value.

    This lens is fat, and a little on the hefty side. 77mm filters will be expensive. It feels very solid, and the zoom and focus rings are smooth and well damped. In fact, these are the best feeling rings I have felt on a modern lens (kind of reminds me of my old manual focus Rokkor days). It comes with a zippered case with belt loop, a very nice bayonet mount pedal hood, and back and front caps (although Sigma's non pinch style lens cap is almost impossible to remove and re-attach when the hood is on).

    The HSM focusing is practically silent and very fast... the focus ring does not turn during auto-focus, and of course you have the option to grab hold of it and manually focus anytime you feel like it. The manual focus ring has no actual stops, but you can instantly feel when you have reached infinity or the near focus point. It would have been nice to see DOF marks on the focus index as well as a few more incremental markings (none between 3 feet and infinity), but other than this and the lens cap (which I will replace with a Nikon one), I could not be more pleased with the feel, fit, finish, and operation of this lens.

    I really like the focal length range of this lens. It was hard to visualize as I bought it sight unseen, and the closest thing I have owned to compare it to was the Nikon 10.5mm Fisheye. At 10mm, the FOV is amazing!

    One of the reasons I was less than thrilled with the Nikon 10.5mm was that it was not all that sharp at the edges/corners (I even sent it to Nikon to be sure there was not an issue with it). The edge to edge sharpness is very good with the Sigma. I have seen many discussions of samples of this lens not being consistently sharp from edge to edge. Doesn't seem to be an issue here.

    I shot some high contrast back lit scenes to test for CA. The Nikon 10.5 was particularly poor at this, especially at the sides and corners. The Sigma seems to be incredibly well controlled, especially for such extreme focal lengths. There is some noticeable light fall off in the corners when approaching 20mm but that is easily fixed in post.

    I did encounter a bit of flair in some shots (like sun peeking through trees) but these were pretty extreme situations that would affect most lenses.

    reviewed December 20th, 2006 (purchased for $485)
  • 9 out of 10 points and recommended by MariuszJ (6 reviews)
    good build quality, price and what you're looking for - 10mm!
    lens cap - very, very poor

    If you like landscape photography - you'll love this lens!Field of view is unbelievable - just keep your aperture around f11 - then you'll get the sharpest photos.
    It has an internal focusing , which eliminates front lens rotation - it's becoming a standard with Nikon, it'll help you use your polarizer.
    Lens build quality is better than I expected, unfortunatelly lens cap could be much better.Other than that - have no complains.Just watch for distortion on close objects - but no problem with landscapes.I also like its well done soft case .

    reviewed December 20th, 2006 (purchased for $420)
  • 8 out of 10 points and recommended by mimic (7 reviews)
    10mm, price, sharpness
    CA, distorsion

    Waouh, what a wide lens, I use it half of the time on my d80, and sometimes take only this one on vacation when travelling light.

    optical quality is very good, exept CA end distortion but it can be easily corrected.

    build quality is also very good.

    While not cheap this lens is not expensive.

    This is one of my prefered lens

    reviewed December 14th, 2006 (purchased for $500)
  • 9 out of 10 points and recommended by gadgetguy (62 reviews)
    reasonably priced, ultrawide, good build quality, fast AF
    could be faster, soft corners

    For an ultrawide solution for an APS-C DSLR, there is no better bang for the buck than this lens. Contruction quality is better than most first-party consumer zooms, and IQ is acceptable (although corners are a bit soft).

    It is small and lightweight.

    Despite its shortcomings, I still recommend this lens whoeheartedly because for the price, there is really no better ultrawide solution for a cropped senser, IMHO.

    reviewed December 14th, 2006
  • 8 out of 10 points and recommended by stoner_eyez (1 reviews)
    Super WIDE!, sharp, and quiet
    None so far.

    I got this lens for my Nikon D80, and it suits it very well. Great lens for a digital camera. The angle of view of really good. I've been using this lens for landscape photography and for taking pictures of cars and it works out great for those type of pictures.

    reviewed December 10th, 2006 (purchased for $690)
  • 10 out of 10 points and recommended by mu55ster (10 reviews)
    Very wide, perfect for digital
    if only f1.4 was possible :)

    This lens has paid for it's self many times over - it's great for interiors and give me the occasional shot that nobody else got at weddings etc (although tends to dwarf people as wideangles do - so be careful). Construction is great - metal would be nice but as if thats ever going to happen - the best thing is being able to put a poleriser on. the hood is good too. image quality is great - gets better around f8-f16 and this is really the range you should be using it in anyway for best depth of feild for tripod mounted shots - wide open needs the occasional USM - a point for pixel peeppers - this is a WIDE lens, you use it to capture a scense of space, if you zoom in expecting to read the lable of a bottle of wine in a shot of a 5x3 meter wall you shot from 4 meters away you'd really be pushing it (4 meters away with a 50mm - no problem, but you'd only have a few bottles) so while it is sharp - remember it's wide as a priority, so you might be dissapointed at first if you veiw at 100% rather than veiwing the whole shot. there is a tiny amount of distortion - easily removed in CS2 or PT lens but i rarely bother - the 12-24mm has less distortion but is much bigger (full frame though) - i put this lens on a film body for some fun - creates a circular image cut off at the sides, this creates a fisheye effect while keeping most of the image rectilinier - great fun, i'd love to try in on a full frame digital. I love this lens - one of my favorites and i'd buy another in a heart beat.

    reviewed November 17th, 2006
  • 8 out of 10 points and recommended by DoFJerk (7 reviews)
    Ultra wide, Silient, Good color reproduction, Low CA
    High Vignette

    This is the favorite lens for outdoor and landscape shooting, that normally use f/8 to f/11.
    Need to stop down to get sharpness for entire frame, wide-open will cause vignette on your photo.
    In real scence, this lens show very little CA while having high contrast and color.

    For Canon fans this lens can beat 10-22, because it price and good image quality.

    reviewed November 16th, 2006 (purchased for $490)
  • 9 out of 10 points and recommended by drwho9437 (9 reviews)
    WIDE!, sharp, hood, HSM
    lens cap

    Its not perfect, but as far as ultra wides go this is the best deal, I think. I had the Tokina 12-24 for a short period. It was so heavy. I kind of wanted the Canon 10-22 but its so much more expensive that I tired the Sigma and I'm glad I did.

    I pretty much got this lens for a trip to New Zealand. 10mm its just great for both architecture and landscapes. You will need to level off for most shots, but not doing so makes for interesting play with the prospective distortion of such a wide lens.

    The build it nice, the focusing ring was very tight when I got it. There are some complaints about QC on this lens, but my copy is fine. HSM is quick and quite. I do wish the throw on the focusing ring was longer so manual focus was more possible.

    This lens isn't fast, but for its target (outside landscapes and arch) it doesn't really need to be. One annoyance is the lens cap. I have tiny fingers so I can get it off with the hood attached, but there is a trick to doing so. I got a Tamron center pinch 77mm cap but sadly the back gets a bit too close to that curvy front element. If I got a UV filter with threads I would use a Tamron cap.

    reviewed November 15th, 2006 (purchased for $480)
  • 8 out of 10 points and recommended by tombell1 (1 reviews)
    Good construction. Smooth movement. Good results although best from 12-18mm
    Not crystal sharp

    Generally a good buy. Ihave a Pentax DS so use the focusing in the camera. generally quick and accurate. The lens is very useful particularily when combined with a Sigma 18-125.
    there is some vignetting at 10 but it really performs well for me.

    reviewed July 12th, 2006 (purchased for $440)
  • 7 out of 10 points and recommended by Zababa (1 reviews)
    sharp, fast, quiet
    heavy, low resolution

    I tried it with Nikon D50 and am gald to have bought it. Hoever, I have expected more crispness and more details. I just don't know whether it is a question of lens resolution or of the resolution of the CCD in Nikon D50

    reviewed January 5th, 2006 (purchased for $650)
  • 10 out of 10 points and recommended by kevindar (2 reviews)
    build quality, sharp, contrasty, minimal distortion

    After doing much research, reading many forums, and testing the canon ef-s10-22, I settled on sigma. Part of reason was that I can still mount it on full frame, albeit under 15mm, its probably not very usable due to severe vignetting. I have done a test on a tripod with a brik wall. At 10mm the center is reasonably sharp, but benefits from some sharpening. the edges are somewhat soft. Stoped down one stop, the sharpness is excellent at center, and two stops, escellent on the edges. there is moderate vignetting wide open at 10, which is easily corrected in photoshop. not much ca to speak of. at 20, shaprness is excellent at center, and a little soft on the edges which improves stopped down. focusing is quiet and very fast. I am very happy with it

    reviewed November 6th, 2005 (purchased for $360)
  • 9 out of 10 points and recommended by kernsm (1 reviews)
    Practically no distortion at 10mm and none at 12mm. No CA and quite sharp!
    Some vignetting below F/5.6

    Excellent feel and the focus is crisp and instant. I was amazed how little distortion at 10mm, and disappearing totally at 12mm and up (using a brick wall for the test). The lens is remarkably sharp wide open with even acceptable corners. The corners sharpen further when stopped to f/5.6.

    I'm glad I passed on the 12-24 mm offerings.

    reviewed October 30th, 2005 (purchased for $480)