9 out of 10 points and recommendedsolid build quality, great focal range, very good IQ through the whole range, low costIQ at 17mm in the very corners a tad soft wide open, could be faster at the longer focal lenghts
I will be as honest as possible to help others in thier decision, but this is for my copy, and copies can vary. On my Samsung GX10 this lens is quite a bit more heavy than the stock lens, although this weight is because of the high build quality, and it does balance nicely on the GX10. The focal range is great and the little extra on both ends is noticable and very useful, compared to 18-55mm lens. The zoom action is smooth and my copy has no creep even shaken lightly upside down. The focus ring is nice, it could be a bit more resistant but its fine. The image quality is very good at 17mm and f2.8 only the deep corners are soft, but most of the frame is good, stopped down just a little and things get better, it peaks at f/5.6-8 and is excellent with great contrast, color and sharpness. You will see the difference over the kit. This quality carries through all of the range. AT 70mm it gets a tad soft in the corners again wide open and it helps to stop it down, peak sharpness is about f8. So it could be a bit faster on that end but its not bad. This lens also has great macro ability and can focus on things almost touching or even touching the front glass element. Bokeh is not bad but not the best, its good and dependent on settings. CA/PF is well controlled as it seems with all Sigma lens, it's there a little, especially at the wide end, but never a problem; I dont need to remove it with PP, becuase its not visiable so far at least. Distortion is fair at 17mm and it has a bit of barrel distortion that I remove with PTlens. Overall thier is no real bad things that this lens does, anything it does not do well is typical with others in its class (average), but its better than average in most areas and that's what makes it a real winner for a walk around lens at its price range. Pentax has just announced thier DA-17-70 f4 lens, it will be interesting to see how it compares. But as it stands now this lens offers great color and contrast, is very sharp and has a great range. The f2.8 at 17mm is usable and it never needs to be down (if your DOF is OK), or has any bad spots to avoid, the whole focal range can be used. CA/PF is never a problem and this lens is just great I have no desire to replace it with any lens offered today as my walk around lens.reviewed June 23rd, 2008 (purchased for $370)
Now 7 years latter and 4 bodies latter (2 Samsung GX10, Pentax K20D, Pentax k-5) this lens is still as stated above. The lens is really sharp on the K20D and going to the K-5 was no problem for it. Its still a lens I don't want to replace. The Pentax DA17-70mm f/4 although good, won't make me sell my Sigma lens and buy it. Now 2015 and Pentax has a DA16-85mm f/3.5-5.6 again Pentax has me interested. It has weather sealing, a AF motor. Wider range. Is it worth it? Yes/No, if you don't have a walk around take a look at it. But for me the Sigma has earned a permanent home along with the K20D for the hard work and superb pics they produced. This is a simple lens that works well. And this model is no longer in production.
10 out of 10 points and recommendedSharp at 300mm f5.8, a bit smaller that it rivals, good control of CA/PFA little expensive compared to it rivals, but worth it.
I have owned the Tamron and Quantaray 70-300mm lens, they had too much PF for me. I bought the Sigma 70-300mm APO instead. The Sigma was fine but for its softness ~300mm at all but the highest f numbers (over f7). The Pentax 55-300mm is very good at 300mm f5.8 peaks at f11, and go down just a tad lower at 270mm and it peaks at f8, this is fantastic performance for a consumer zoom lens. This lens is sharp and usable wide open from 55-300mm! This lens has much better control of CA/PF over the Tamron, not as good as the Sigma APO, but its not a problem and I never have to deal with it in PP. Of course the Pentax lens is more expensive than its rivals the Tamron/Sigma lens but well worth it. This lens has exceeded my wants for a consumer telephoto lens by a good margin and is my favorite lens. You can just put this lens on your camera and shoot at any aperture and focal length with sharp results. Its sharper than the Sigma or Tamron and has very good CA/PF control, as well as being smaller and lighter, How did Pentax do it? Highly recommended.reviewed June 28th, 2008 (purchased for $370)
7 out of 10 points and recommendedSuperb CA/Pf performance, good build, nice contrast even out to 300mm, great macro modePoor resolution from 200-300mm, need to be at f8 for OK, and f11 for good IQ
As some pro reviews say, I recommend this lens with "some reservations", if you don't care about 200-300mm sharpness or don't mind having to be at f11 or higher to get good results at 300mm. Now that's the only thing this lens does bad, its kinda a shame because everything else is good. It has very good contrast probably from having 3 ED elements, and those ED elements totally banish CA/PF, and better than any other ##-300mm consumer telephoto (from my research). The IQ performance below 200mm and at f8 is very nice, good color, sharp. Macro performance is great all the way to 300mm, this lens is sharp at f8 300mm at things 1m away but not 100m away, could be by design. Seems Sigma made it the best at CA/PF, great at macro, great up to 200mm, at the expense of sharpness 200-300mm. So you decide, you could think of it as a 70-200mm lens with outstanding performance for the price?? lol and with macro.reviewed February 2nd, 2009 (purchased for $219)
Even if you own a fine 300mm lens, you could use this as a light bag lens that can do macro and high IQ shots up to 200mm. With a tripod, and non moving object, this lens can produce some serious pics. At the price, it does have serious competition. And I can only recommend it, if performance in the 200-300mm is of little concern to you, and you need its other strengths.
9 out of 10 points and recommendedWide! 10mm versus 11mm or 12 is a big differance, great IQ, low CA/PF, low barrel, low costA tad soft at 10mm/f4 in the deep corners; vignetting could be a bit better
Using this for my Samsung GX10 (Pentax K10 brother).reviewed February 2nd, 2009 (purchased for $500)
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.
9 out of 10 points and recommendedWeather-Resistant, Metal Mount, Non-rotating front element, Good Lens Hood, near the top in image quality for Kit Lens, outstanding value.Vignetting and Soft Corners with some field curvature. Most problems go away as you stop down, not a fast lens.
My numeric ratings are compared to other kit lens. What other kit lens is built better than this weather-resistant Pentax(?), none. It is WR, has a metal base, has a decent lens hood with a special removable cut-out so you can turn CPL filters, the front element does not rotate. Its at the top of kit lens in construction, that's fair IMO.reviewed March 3rd, 2010 (purchased for $219)
As for the image quality its the same as the DA18-55mm II, no need for me to repeat SLRGears review or others. I concur its a good zoom lens. The biggest difference to me compared to the old Pentax kit - this one has that Pentax color and contrast, or should I say more of it. Its a fairly contrasty kit, with those Pentax colors. shoot at F8 and your taking home high quality pics.
9 out of 10 points and recommendedJust a tad bigger than DA18-55mm. Solid Build. Weather Resistant. Nice RangeIt could be a bit sharper. But not bad
Rating this lens is hard. In general, yea its got soft spots and the DA55-300mm is much longer and sharper. However when compared to other APS/FF lens of 50-200mm or 75-300mm this lens is as good. Really better if you put a Sigma 70-300mm APO on a FF. This lens gives the APS shooter a superb bargain then. Better sharpness, small, less costly, and light.reviewed November 15th, 2014 (purchased for $250)
This is the lens strongest strength it is small for a telephoto lens. Second strong trait is it feels good in your hands, solid. IQ takes getting to know the lens.
Recommend if you want small, light, telephoto with weather resistant build, and won't cost much.
8 out of 10 points and recommendedSuperb IQ, Light weight, Decently fast f/2.4, Small, Pentax Color/ContrastLens Mount made of Plastic, No Distance Scale on Focus Ring, No WR
This is the highest IQ lens I have used on my K-5. This lens is sharp wide open. At f/4 and above the sharpness, contrast, color, and overall lack of aberrations leave little PP work to be done. You can shoot right into the sun with no flair (be careful). It has lower CAs versus its FF big brother. I believe this version is an improved version; although a bit slower.reviewed June 16th, 2013 (purchased for $217)
Edit: When I run across my reviews if time has lapsed far enough for an update I will do so. I have owned this lens for about one year. All statements still stand. No wear on the lens mount. Still tight feeling. The lens is very fast to focus. Using a round lens hood made for lens of 50mm (FF = of this lens) makes a notable difference in contrast and overall pic quality in some situations! This lens has become my go to lens over my Sigma 17-70mm f/2.8-4.5 Macro; in most situations. Say a quick snap of people, web shots, or just things. The DA35mm is lighter and a bit sharper. The Sigma is no slouch however. Very versatile focal length. I can see now why all should own a true 50mm lens. And this is a solid low cost but high IQ lens for Pentax shooters.