[Jewelltrail]

Thanks much for posting examples, Jewelltrail. Love the Desolation Trail photo! But... it looks soft, doesn't it? (ducking)

I'm trying not to read too much from the sharpness tests. According to Photozone, at f/8 the DA should be sharp from corner to corner, but in the image below (shot at f/8) the bottom left corner is soft, while the center of the frame is sharp - look at the high-res image linked below.

By the way, this site definitely softens images embedded into posts.

High-resolution

Correct me if I'm wrong--you are suggesting I trust your evaluation over Photozone's???

Photozone provides objectivity--Da & Siggy are virtually tied. Do copies vary--of course. Do compression softwares vary--of course. Do people's tastes vary--of course. Here is the same shot with a little sharpening applied. BTW, this shot is @ 10mm--how sharp is the Da @ 10mm? And here is another from that hike @ 10mm--just below:

[northcoastgreg]

Some images in your gallery are made with DA 12-24. Have you used Sigma 10-20, and how would you compare them?

I have not used the Sigma 10-20, but I did extensive research on it a year and a half ago (as well as the all the other UWA zoom and prime lenses that were available at the time for the Pentax mount) when I was making my decision as to which lens to purchase. I've seen plenty of sharp pictures taken with the 10-20, and the photozone tests seem to back up that perception.

I ended up choosing the DA 12-24 because (1) I needed the 20-24 more than the 10 to 12; (2) the 12-24 appeared to have better color rendition than the 10-20; (3) the 10-20 had problematic wavy distortion that would cause issues with seascapes; (4) the 12-24 seemed to have better corner to corner resolution, which is important in landscapes.

In retrospect, I think only reasons no. 1 and 2 are all that important. No. 3 might be important if you take pictures of large bodies of water where a straight horizon is desirable; otherwise, the fact that one UWA zoom has a little more distortion than another is largely insignificant in landscape work. Nor would I get caught up in the photozone resolution tests. Those give a useful general indication of a lens' resolution, but there's a lot more that goes into the IQ of a lens than mere resolution. The higher-end Pentax lenses are designed more toward beauty of rendering than how will they do on numerical tests. That's where lenses like the DA 15 and the DA 12-24 really shine. They render light with great clarity, contrast, and beauty of color. But that extra jolt of IQ is going to cost more money, perhaps appreciably more money, and each individual has to decide for himself whether these immeasurable differences in rendering are worth the extra price.

[Kammerer]

I have not used the Sigma 10-20, but I did extensive research on it a year and a half ago (as well as the all the other UWA zoom and prime lenses that were available at the time for the Pentax mount) when I was making my decision as to which lens to purchase. I've seen plenty of sharp pictures taken with the 10-20, and the photozone tests seem to back up that perception.

I ended up choosing the DA 12-24 because (1) I needed the 20-24 more than the 10 to 12; (2) the 12-24 appeared to have better color rendition than the 10-20; (3) the 10-20 had problematic wavy distortion that would cause issues with seascapes; (4) the 12-24 seemed to have better corner to corner resolution, which is important in landscapes.

In retrospect, I think only reasons no. 1 and 2 are all that important. No. 3 might be important if you take pictures of large bodies of water where a straight horizon is desirable; otherwise, the fact that one UWA zoom has a little more distortion than another is largely insignificant in landscape work. Nor would I get caught up in the photozone resolution tests. Those give a useful general indication of a lens' resolution, but there's a lot more that goes into the IQ of a lens than mere resolution. The higher-end Pentax lenses are designed more toward beauty of rendering than how will they do on numerical tests. That's where lenses like the DA 15 and the DA 12-24 really shine. They render light with great clarity, contrast, and beauty of color. But that extra jolt of IQ is going to cost more money, perhaps appreciably more money, and each individual has to decide for himself whether these immeasurable differences in rendering are worth the extra price.

Greg, thanks a lot for sharing your thoughts on this.

Jewelltrail, thank you for the examples, they are very useful.

[Jewelltrail]

I have not used the Sigma 10-20, but I did extensive research on it a year and a half ago (as well as the all the other UWA zoom and prime lenses that were available at the time for the Pentax mount) when I was making my decision as to which lens to purchase. I've seen plenty of sharp pictures taken with the 10-20, and the photozone tests seem to back up that perception.

I ended up choosing the DA 12-24 because (1) I needed the 20-24 more than the 10 to 12; (2) the 12-24 appeared to have better color rendition than the 10-20; (3) the 10-20 had problematic wavy distortion that would cause issues with seascapes; (4) the 12-24 seemed to have better corner to corner resolution, which is important in landscapes.

In retrospect, I think only reasons no. 1 and 2 are all that important. No. 3 might be important if you take pictures of large bodies of water where a straight horizon is desirable; otherwise, the fact that one UWA zoom has a little more distortion than another is largely insignificant in landscape work. Nor would I get caught up in the photozone resolution tests. Those give a useful general indication of a lens' resolution, but there's a lot more that goes into the IQ of a lens than mere resolution. The higher-end Pentax lenses are designed more toward beauty of rendering than how will they do on numerical tests. That's where lenses like the DA 15 and the DA 12-24 really shine. They render light with great clarity, contrast, and beauty of color. But that extra jolt of IQ is going to cost more money, perhaps appreciably more money, and each individual has to decide for himself whether these immeasurable differences in rendering are worth the extra price.

I spent a lot of time researching my UWA choices too. One reason for why we went different ways with the research, was because I owned the Tamron 17-50 f 2.8, and was happy with its performance between 17-24mm. So, the extra reach of the Da was of no importance to me: I was looking to fill the UWA gap 16mm & below.

The so called "mustache distortion" of the Sigma is at its 10mm extreme--the more you zoom out with the lens the better controlled distortions get. I had seen real estate shots with the 10-20, @ 10mm, before I bought it, & was confident the distortion was of no significance to me. Here is a shot @ 10mm, just to provide an example:



The shot is 10mm, not cropped, and not corrected for any kind of distortion. in other words, this is as bad as the distortion gets on the 10-20.

One other reason I went with the 10-20, was because it controls CA much better than the Da 12-24 does. And the colors of the 10-20 are more appealing to me than either Da choice, though I usually PP colors to my taste anyway, as you can see in the above shots.

Kammerer, all 3 of the choices discussed here are excellent. It is a matter of where your priority lies. Best of luck.

JT

[yyyzzz]

Sigma is great. A bit heavy for me. Rarely use the 10 side. So I sold it.
DA15 is light and good for landscape. Allow 49mm PF filter.
Samyang14 is great and can be used indoors.

Can not go wrong with any of them.

[Kammerer]

Kammerer, all 3 of the choices discussed here are excellent. It is a matter of where your priority lies. Best of luck.
JT

I've been informed by the High Command that my priority lies in procuring the 43mm Ltd. The funds have been redirected.