GENorkus Loc: Washington Twp, Michigan

It's not a zoom but the 15mm Blackstone seems impressive.
http://en.irixlens.com/15mm

rfmaude41 Loc: Lancaster, Texas (DFW area)

Irix also has that (both Blackstone and Firefly) in 11mm. And the 11mm lenses will cover a FF sensor, also, they have a Pentax version.

willaim Loc: Sunny Southern California

I have the Sigma 10-20 3.5 which on a crop sensor(Canon 80D) equals about 16-24 mm. Couldn't be happier. Sharp and is excellent for indoor shooting and, of cause, for landscapes. You'll need
a thin 82mm filter(Sigma wide circular PL) to prevent any vignetting.

amfoto1 Loc: San Jose, Calif. USA

Tamron doesn't make a 12-24mm. Tokina used to, but superseded it with a 12-28mm f4 a year or two ago. Both those Tokina are good lenses. The Tokina 11-20mm f2.8 is, too, but it's larger, heavier and more expensive (it superseded an earlier 11-16mm f2.8). On an ultrawide lens, most people actually don't need an f2.8 lens... they just think they do.

Tamron makes a 10-24mm ultrawide. It's okay, but personally I think the Tokina are better lenses.

HOWEVER... TOKINA 12-24mm, 12-28mm, 11-16mm, 11-20mm and 10-17mm ARE NOT OFFERED IN PENTAX MOUNT. This is probably by agreement between the two companies so that the less expensive, but equal quality Tokina don't compete with the Pentax lenses.

Instead, Pentax themselves offers a 12-24mm f4 that's manufactured for them by Tokina. (They also both sell a 10-17mm, but that's actually a fisheye zoom... with stronger, less-corrected wide angle distortions.)

Sigma makes 10-20mm in two versions.... One is a smaller, lighter, less expensive variable aperture (f4-5.6 or f4.5-5.6?). The other is a bigger, heavier, more expensive non-variable f3.5 version. The latter has been on sale lately, which makes me suspect they are about to replace it with a new model and are discounting it to clear the shelves of the older one.

So, actually your only ultrawide zoom choices for use on a K-3 are:

- Pentax 12-24mm f4
- Tamron 10-24mm f3.5-4.5
- Sigma 10-20mm f3.5

If you consider used too, you might be able to find the Sigma 10-20mm f4.5-5.6.

I've used a Tokina 12-24/4 for many years on my Canon cameras... I liked it's build and image quality better when I compared with the Tamron and Sigma lenses. But, for Pentax cameras that's only available in the Pentax version, which sells for about $700 (compared to the Tamron 10-24mm and Sigma 10-20mm for around $450-$500.)

BudsOwl Loc: Upstate NY and New England

I had the 10-20 Sigma for my Canon 60D. It worked very well, but sold it when I bought the Canon 6D since the lens was only for a crop sensored camera.
Bud

j.l.h

You will need to shop for the older (2009?) version. The newer lens doesn't come with a Pentax mount. Adorama has some on closeout:
https://www.adorama.com/tm1024pxaf.html

boomer826 Loc: Florida gulf coast

If I was going to be toking on something, it wouldn't be a lens (lol) !!!

shangyrhee Loc: Nashville TN to Sacramento CA

Thank you so much for your info & advice. Shang

team 1

I have the sigma 10-20 EX DC HSM and I love it

GENorkus Loc: Washington Twp, Michigan

Shangyrhee, please read this! ...and others that might be interested in a lens like what you are interested in.

Please note that I just picked the first type lenses that fit what I'm talking about. It has NOTHING to do with the company or indivual who I'm not familiar with.

Here is an example only:
http://www.ebay.com/itm/Sigma-12-24mm-f-4-5-5-6-DG-AF-Lens-for-Pentax-AF-/172520345062?hash=item282b038de6:g:LMwAAOSw9GhYmksb

http://www.ebay.com/itm/Sigma-EX-DG-Macro-24-70mm-f-2-8-DG-Lens-For-PENTAX-RICOH-/322443373847?hash=item4b131f6d17:g:IUsAAOSwhlZYuOSM

http://www.ebay.com/itm/RARE-MINT-PENTAX-SIGMA-MACRO-EX-50MM-F-2-8-K-MOUNT-LENS-K-1-K-7-K-5-BEST-PRICE-/182464485833?hash=item2a7bbb19c9:g:0ZsAAOSw32lYqABk

Sigma made them a "generation" back and have since improved them to be one of the best out there.

Note the aperture ring. It is located very close to the connection to the body. It is nearly impossible to turn manually. I only say this because you can still get them in great condition on the used market. I bought one, used it for a couple days, and sent it back pronto!

If you do get one like this, set it to auto, put it on your camera. You'll have a great lens and normally for an excellent price.

shangyrhee Loc: Nashville TN to Sacramento CA

Thank you for the info. Shang

shangyrhee Loc: Nashville TN to Sacramento CA

Thank you for the info. Shang

shangyrhee Loc: Nashville TN to Sacramento CA

Thank you for your info & advice. Shang

raysass Loc: Brooklin, On, Canada.

MT, I respect your opinion and that's why I have to ask. Why is speed in focusing so important with a wide angle lens?
Ray.

wolvesaywe Loc: Hants England

I have the sigma f3.5 , a cracking lens on my d7200 .