[ramseybuckeye]

I have the Tamron 10-24, It's a pretty sharp lens and reaches infinity focus pretty quickly. The front element is large and it is prone to flare if you point it towards the sun or a really bright light. At the wide side you will get a lot of distortion. I can't compare it to the Pentax or the Sigmas as I have no experience with them.

[mtgmansf]

I considered the 10-20 Sigma also. However, after a lot of reading and pondering I have put that aside for various reasons including some of those stated above. I have a DA15 (which is somewhat redundant to the 10-20) and the DA15 is a very nice lens and recommended from where I sit. What I would really like is a relatively compact 10-12mm prime (the Samy 10mm is too big for my taste). We will just have to see what time brings.

Understand. The Pentax 15mm is a fine lens for now. Too bad Tokina does not make their famous 11-16mm f2.8 for Pentax. Frankly, I love having a zoom for the ultra-wide range and I am thinking of dumping all my Pentax stuff, should Pentax not come up with a WR ultra-wide zoom in the near future, since I am tired of the the limitations of the Sigma.

[robgski]

What I would really like is a relatively compact 10-12mm prime

I encourage you to look at the Pentax 10-17mm. I've rented it twice, it's very sharp all across the range as I mentioned above, and it's pretty compact, I've walked and hiked comfortably with it.
I would buy one, several are for sale on PF, but I am saving up for a 77mm and a K-1

Interesting mtgmansf- thanks.
The K30 worries me with the aperture failure issue. I've had a couple of shots come out like that. As far as I'm aware the K5 series doesn't have that issue whereas the lower models do seem to suffer from it.
Test images of the K5iiS always seem to look a bit clear/sharper at 100%. Maybe it doesn't show up on real shots less 100% (?)
The 55-300 has produced the sharpest images for me.
I'm awaiting the repair of my Sigma lens. When I get it back it should help me decide whether to stick with the K30.

---------- Post added 08-05-16 at 04:55 AM ----------

I encourage you to look at the Pentax 10-17mm. I've rented it twice, it's very sharp all across the range as I mentioned above, and it's pretty compact, I've walked and hiked comfortably with it.
I would buy one, several are for sale on PF, but I am saving up for a 77mm and a K-1

Isn't it a fisheye lens? It'd be nice to have a fisheye but I'm after something with less distortion at the moment.

---

Last edited by Oricman; 08-05-2016 at 04:56 AM.

[mgvh]

{RE: DA 10-17} Isn't it a fisheye lens? It'd be nice to have a fisheye but I'm after something with less distortion at the moment.

Yes it is, but it's not very fishy at all from 15-17mm, and it's quite de-fishable from 12-17mm. The Lens Profile Correction in LR CC does a pretty good job, so it's a single-click deal if you want to defish.
I've done a bunch of testing /comparison HERE, and be sure to read Heie's comparison of 4 UWA, including section 9 on defishing.

[pepperberry farm]

I'll second (or third?) the remarks for the DA10-17mm; by 14/15mm, you'll lose the fish-eye distortion and just be shooting with an UWA lens....

and, on the flip-side, you get an amazing 10-13mm fisheye zoom that is so full of fairy-dust....

https://www.flickr.com/photos/pepperberryfarm/albums/72157659032799212

[pres589]

The 10-17 seems like a really fun lens to use once mastered (I've never touched one). That said, I really really like my SMC 15mm Ltd and am kicking myself for not finding the money for one sooner. The only way I can get it to flare is by use of a protective filter & bright light, and even then the thing won't always flare or flare very noticeably. And the thing is an easy carry in a jacket pocket.

[KC0PET]

I encourage you to look at the Pentax 10-17mm. I've rented it twice, it's very sharp all across the range as I mentioned above, and it's pretty compact, I've walked and hiked comfortably with it.
I would buy one, several are for sale on PF, but I am saving up for a 77mm and a K-1

Yes I am sure I will end up with the 10-17 sooner or later...

[forensicscientist]

I've been down this road too....had a Sigma 10-20, and Tamron 10-24. After reviewing the exif data, most of my shots were no wider than 15mm. Finally settled down with the DA 15 and 21mm.....light and sharp. They've worked well for me.

[mtgmansf]

I've been down this road too....had a Sigma 10-20, and Tamron 10-24. After reviewing the exif data, most of my shots were no wider than 15mm. Finally settled down with the DA 15 and 21mm.....light and sharp. They've worked well for me.

I can assure you, the Sigma at 10mm is 10mm or 15mm on the K1/FX. Compared the field of view with a friends 14-24 Nikkor on the D800e! Big difference shooting a dx camera at 15mm vs. 10mm. Have not used the 10-17mm, since it is Fishy at the sort end and already use the wider 8mm Samyang for that with de-fishing. Still, a zoom is a zoom and far more versatile under harsh elements, than switching primes which exposes sensor, mirrors, screen, etc. to destructive elements!

[bhbrake]

I have had the Sigma 10-20mm for about a year, and I shoot about 50% of the time with it on. Most of what has been said about it is fairly accurate regarding the corners being somewhat soft. The pentax 14mm was not an option for me because it was not wide enough for what I wanted, but it does offer much better low light performance. I have been very happy with Sigma for the most part, and am rather fond of the color reproduction. Sharpness on center is quite good. It has been a durable lens- I am pretty hard on my gear (rain storms, canoe rides, hiking, fishing, wild children...)and have not had any issues with it.

Here is on I shot last week with it that is about as sharp as I can get with it at the long end of the range a few stops down ( B&W, f6.3, 20mm)

Has anyone compared the Sigma 15mm with the Pentax and Samyang versions?

I like the range zooms give you and can get a Sigma 10-20 second hand for about the price of a Pentax 15mm. It seems hard settling on one or the other. Prime is smaller and lighter and sharper. Zoom offers more range.

[WPRESTO]

Various comments:
1) Had A Sigma 10~20mm (original version) and replaced it with a Sigma 8~16mm. The latter is IMHO significantly better and an excellent ultra-wide.
2) I also have a Pentax 10~17mm. When fully defished, all you really lose is the corners where there is rarely anything of interest. The edge-to-edge coverage of the 10~17 @ 10mm is insignificantly different from the coverage of the Sigma 8~16mm @ 8mm (SEE REVIEW OF FOUR ULTRAWIDES HERE ON PF. I agree with the PF assessment that the Pentax 10~17, because of its compact size and extreme coverage, is enormously convenient to take-along).
3) RE: Irix is scheduled to introduce a 15mm f2.4, although it is doubtful it will be superior to a DA 15mm on APS-C and not the best choice if you use that format. However, they are also developing/promising an SFL of about 11~12mm in the near future (what does that mean: end of summer or end of 2020?). That might be a lens worth a serious look when/if it is released.

IMHO: If you want really ultra-wide on APS-C, the Sigma 8~16mm is the lens of choice. If you do not need extreme ultra-wide, the DA 15mm is excellent and extremely compact, but be sure it is wide enough to meet your expectations. If you don't mind spending PP time to defish, the Pentax 10~17mm has excellent quality, extreme coverage, and compact size (much smaller than a Sigma 8~16mm) as well as a reasonable price. Keep an eye out for the Irix 11~12mm, it might be a game-changer (or a pricey disappointment).

[FoxbatK]

I am coming from shooting film, so I really needed 35mm equivalent of better than 17mm wide angle since I'm not much of a talented photographer as I am someone who likes framing a really wide view into one shot

The 12-24mm and 10-20mm three way comparison on this website is priceless -

DA 12-24mm vs Sigma and Tamron 10-24mm Comparison Review - Introduction | PentaxForums.com Reviews

They link to an addendum review.

I needed all the wide angle I could get, so I went with the Sigma 10-20mm/f3.5 after reading that review and looking at the Samyang 10mm and 14mm primes. Attached are some pictures, including one stopped to f3.5 indoors. I'm sure the pro's here would see it some bad effects at the edge, but I'd prefer to have the extra wide view though subpar view as long as the center is stunning.

I would've gotten the 10mm Samyang since I grew up admiring the sharpness of primes, but you can't attach a filter ring easily and I already noticed two nicks in my protective filter - hard to keep pebbles off if you're in a precarious spot mid shot while hiking!

The glaring (hah) weakness to this lens is indeed some flaring, but I've been able to work around that or switch to the kit 18-135mm and give up the wide angle shot if needed.