[JHD]

If you need close focus, get a prime. The DA15 is rated at 18 cm and the DA14 at 17cm. Whereas the DA12-24 is 30cm.

The DA15 will focus as close as 7" and the 10~20 will focus as close as 9.5". I have both and they are very different lenses. If you can only have one, it comes down to what compromises are you willing to make. Between the the Sigma 10~20 and the DA15 I wouldn't take one over the other, and I don't see myself buying another UWA. IMO there is no best in the absolute sense, just different.

[hangu]

Thanks, Rparmar for the breakdown. Which lens has the best color rendition and sharpness? (dumb questions, I know)

[Marc Sabatella]

Not dumb, but "best color rendition" is extremely subjective (and with digitla, largely irrelevant), and "best sharpness" is tricky to answer as it depends on what focal length you shoot (for zooms), what aperture you set, and whether you look more in the main central area of the image or concentrate more on the edges borders or the extreme corners. Basically, they each have specific combinations of these where they win, and others where they don't. But they are all good enough, and the differences are smal enough, that sharpness is just not a significant differentiator compared to the other traits.

[fractal]

My next lens purchase will be an UWA and i'd probably be looking at the Sigma 10-20. Unless of course I pick up an aps-c Canon then it would definitely be the 10-22.

It's a pity the Tokina 11-16/2.8 does not come in a Pentax mount as i've heard it's a pearler and ridiculously sharp.

[wlachan]

Just did 2 test shots with my DA14 (K-m) & EF-S10-22 (40D) at f4 & f8, on tripod with precise focus & timer, LR2.7 converted w/o sharpening. Will let you be the judge.

DA14 vs EF-S10-22 Photo Gallery by Alan Chan at pbase.com

[hangu]

Not dumb, but "best color rendition" is extremely subjective (and with digitla, largely irrelevant), and "best sharpness" is tricky to answer as it depends on what focal length you shoot (for zooms), what aperture you set, and whether you look more in the main central area of the image or concentrate more on the edges borders or the extreme corners. Basically, they each have specific combinations of these where they win, and others where they don't. But they are all good enough, and the differences are smal enough, that sharpness is just not a significant differentiator compared to the other traits.

Very true, but I'm sure someone has done a test to see how the DA 15 compares with the DA 12-24 set a 15mm and the same aperture opening in terms of flares, CA and sharpness.

I do believe color rendition is just as important on digital. A few of my old Takumars and K lenses tend to clip saturate reds and blues. The entire area would be a mass of super saturation and it's impossible to fix in PP. However, my 35-105mm A lens is the only one that handles super saturated reds and blues well.

[Lowell Goudge]

If you need close focus, get a prime. The DA15 is rated at 18 cm and the DA14 at 17cm. Whereas the DA12-24 is 30cm.

If you need another stop of light, get the DA14. It's f/2.8 versus f/4.

If you need ultimate compactness, get the DA15.

If you need distortion-free IQ, get the DA12-24 or one of the primes.

If you need the ultimate in coverage, get a fisheye and de-fish in PP as needed.

If you need versatility, get the DA12-24. The 24mm end is very useful and may save you time swapping lenses for street shots and in other "normal" FOV situations.

If you prefer a compromise between fish-eye wide and rectilinear convenience, get the Sigma 10-20. Remember that the wide end is not distortion free, but that might not matter depending on what you shoot.

If you need to save money, get the Sigma 10-20.

your logic is perfectly flawless if you are a pentax salesman, or you only think that 14-15,mm is all that is needed, but badly flawed otherwise.

the sigma 10-20mm f4-5.6 has about the same level of barrel distortion as the pentax 12-24mm and has the extra field of view, down to 10mm, In fact de-fished the pentax 10-17 only covers about 12mm so it gets you nothing, it is a fisheye, and leave it at that.

Additionally, what little distortion there is in the sigma can easily be taken care of in post processing, and to a much easier extent than the 10-17 fish eye.

If there is a need for 10mm, the options are very limited and the sigma lens is very very good. I don't know about the 11-16, ot the tameron 10-24, but the first issue should be to determine the focal length needed, For me, and this is only what suites my taste, 24mm on film just was not wide enough. I finally got the field of view I was looking for when I got my *istD, which came with an FA-J 18-35 full frame lens. remember 24mm on film is 16 on an ASP-C sensor, but 18mm on film is about 12mm. I needed at least this, and ultimately chose the sigma (when the real options were the sigma 10-20 and pentax 12-24) .

[rparmar]

your logic is perfectly flawless if you are a pentax salesman, or you only think that 14-15,mm is all that is needed, but badly flawed otherwise.

Of the eight statements I made you attempted to show me wrong on one of them. Apparently this was enough for my entire post to be "badly flawed". Why such hyperbole? Maybe you're the salesman?

My post attempted to address the needs of various wide angle shooters, without bias. Nowhere did I say that 14-15mm is all any photographer needs. But it could indeed be all a given photographer needs. I am not sure why that is so hard to understand. Unless you simply don't get that other people might have different priorities from yourself?

As to my single potentially incorrect statement...

the sigma 10-20mm f4-5.6 has about the same level of barrel distortion as the pentax 12-24mm

The Pentax is basically free of distortion at 24mm (-.148% according to photozone.de) and has little at 18mm (-.578%). At 12mm it is at its worst, -2.11%. These results certainly conform to my experience of the lens: wide open it has noticeable distortion that might be annoying in certain cases.

However, the Sigma 10-20mm has never less than .776% distortion, about six times the Pentax minimum. It never even comes close to the Pentax IQ by this measure. And it too has significant issues at the wide end, in a rather unusual fashion: the middle of the field is a noticeable -1.4% but the corners go up to 3%.

Additionally, what little distortion there is in the sigma can easily be taken care of in post processing

No, sorry, the unusual nature of the Sigma distortion characteristics wide-open makes it difficult to correct. Even the distortion at 12mm in the DA12-24 lens is difficult to remove entirely.

In fact de-fished the pentax 10-17 only covers about 12mm so it gets you nothing, it is a fisheye, and leave it at that.

I had in mind the Samyang 8/3.5, which I am sure covers far more than any of the other lenses we are discussing. It uses a stereographic projection and so has far less distortion that the Pentax fisheye. Perhaps it it you, not me, who needs to think beyond the Pentax and Sigma options.

If there is a need for 10mm, the options are very limited and the sigma lens is very very good.

If it was a clean and usable 10mm I would be more inclined to agree. But otherwise saying it is "very very good" is exaggeration, pure and simple. I would reserve that sort of praise for a lens with better build and IQ than the Sigma. (And no, I don't think the DA build is perfect either.) Apparently the fact that the Sigma has 10mm trumps all other concerns for you. I anticipated this point of view in my second-last point in that same "badly flawed" post... so "badly flawed" it incorporates your own viewpoint.

However, none of your statements on the other matters covered here hold any water.

[rparmar]

Thanks, Rparmar for the breakdown. Which lens has the best color rendition and sharpness? (dumb questions, I know)

I agree with Marc on colour rendition. It's easy to shift colour in digital and your lighting source will have more of an effect (in many cases) than any difference in lenses. That said, I have always liked the Pentax rendering; their coatings are second to none.

As far as sharpness, I will refer to photozone.de. The DA12-24 gets very good and excellent ratings no matter what the focal length, even wide open, even at the extreme borders. Wide open at 10mm the Sigma achieves only fair at the borders, until you stop down to f/8. For a portrait lens the extreme borders might not matter, but for wide angle it's what the lens is all about.

However the DA lens shows the usual Pentax weakness in terms of chromatic aberrations, ranging from 0.8 to 2.6 pixels at the border. The Sigma manages 0.5 to 1.6, which is significantly better. However CA is easily corrected in PP; regardless I have never had to do so. For me it is a total non-issue, but I mention it for completeness.

[JHD]

If you need close focus, get a prime. The DA15 is rated at 18 cm and the DA14 at 17cm. Whereas the DA12-24 is 30cm.

If you need another stop of light, get the DA14. It's f/2.8 versus f/4.

If you need ultimate compactness, get the DA15.

If you need distortion-free IQ, get the DA12-24 or one of the primes.

If you need the ultimate in coverage, get a fisheye and de-fish in PP as needed.

If you need versatility, get the DA12-24. The 24mm end is very useful and may save you time swapping lenses for street shots and in other "normal" FOV situations.

If you prefer a compromise between fish-eye wide and rectilinear convenience, get the Sigma 10-20. Remember that the wide end is not distortion free, but that might not matter depending on what you shoot.

If you need to save money, get the Sigma 10-20.

Which of these lenses do you own or at least have extensive experience with?

[hangu]

I agree with Marc on colour rendition. It's easy to shift colour in digital and your lighting source will have more of an effect (in many cases) than any difference in lenses. That said, I have always liked the Pentax rendering; their coatings are second to none.

Try shifting clipped reds, yellows and blues. You just can't.

[fractal]

Just did 2 test shots with my DA14 (K-m) & EF-S10-22 (40D) at f4 & f8, on tripod with precise focus & timer, LR2.7 converted w/o sharpening. Will let you be the judge.

DA14 vs EF-S10-22 Photo Gallery by Alan Chan at pbase.com

I can't really see much difference in these shots other than the Canon is slightly warmer. You could have shot with the EF at 14mm?

[hangu]

I can't really see much difference in these shots other than the Canon is slightly warmer. You could have shot with the EF at 14mm?

Really? You can't? The EF is well adjusted for distortion while the other lens is bending the rails in a slight W shape. The resolution isn't high enough to judge sharpness.

[wlachan]

I can't really see much difference in these shots other than the Canon is slightly warmer. You could have shot with the EF at 14mm?

The reason is that Canon is 1.6x while Pentax 1.5x. Colour renditions are quite different from both cameras.

[wlachan]

Really? You can't? The EF is well adjusted for distortion while the other lens is bending the rails in a slight W shape. The resolution isn't high enough to judge sharpness.

Oh... you might click "original" to see the 10MP jpegs.