[Jonathan Mac]

They're very different lenses. The DA 21mm is a good general-purpose walk-around lens - wide but not exceptionally so. The DA 15mm is a speciality lens due to being a super-wide and is only really useful for scenes that demand a very wide field of view or where you want to exagerate with perspective distortion. I'd rate the IQ of the 21mm as higher too (better contrast and sharper).

Though the 21mm is the more useful of the two, the 15mm is worth having if you value a compact prime with a very wide field of view.

[Theov39]

Thank you very much all of you for your considered opinions. I appreciate you taking the time to reply. Sounds like the 15mm is the way to go. I always loved using 24mm lenses in my film days and have been missing that.

---------- Post added 02-26-18 at 01:58 PM ----------

I have both, love both. In my bag they fulfill different roles. The 21 is a wide normal (true normal on APS-C would be 28 mm). The 15 is a wide.

The 21 is an awesome street lens for walk around that handles landscapes as well. Things appear normal through the 21. The 15 add drama to landscapes. It pulls the foreground forward and pushes the background further back. This is typical of ultra wides.

I use both and believe that you would miss capturing some dazzling perspectives without the HD DA 15. Looking at the few photos in my Pentax Forums gallery - it’s a HD DA 15 shot that gets the most views.

Some very good points. Thank you!

---------- Post added 02-26-18 at 02:00 PM ----------

Plenty of people have both, Theo.

A good trio is the 15, 21 and 70.

That would be a good goal to aim for. I like the idea of traveling light with just three small lenses. Great match for my K-3 too.

I have zoom lenses but invariably just tend to one end or the other rather than the full range.

---------- Post added 02-26-18 at 02:07 PM ----------

I have chosen the triad 15mm, 35mm, 70mm in APS equivalent to about 23,53,107, so I find them suitable for many occasions and very light weight. It depends on subjective requirements.

Below are the reviews of all four,

Pentax SMC-DA 15mm f/4 AL ED Limited - Review / Test Report

Pentax SMC-DA 21mm f/3.2 AL Limited - Review / Test Report

Pentax SMC DA 35mm f/2.8 Limited macro - Review / Test Report

Pentax SMC DA 70mm f/2.4 Limited - Review / Lab Test




I had the Sigma 8-16 is a good optic, but you can't use filters, that's why I sold it.

Thanks for those links. Very useful. Mind you, I came here looking for a 15mm and now it appears that I also NEED a 70mm LTD!

---------- Post added 02-26-18 at 02:13 PM ----------

DA★ 11-18mm is ..... coming. Not sure when but that is another option to consider.

That could be worth considering but I assume it will be quite bulky like the Pentax 12-24. The 21mm is one my favorite lenses exactly because, in addition to the high optical quality, it is so compact. That also appeals to me with the 15mm prime.

[normhead]

The Sigma 8-16 is a fine lens. I sold mine because the size seemed at odds with my goals for APS-C gear, but it gave me some memorable images despite their voracious need for aggressive processing.





It can change an ordinary view into something extraordinary.

Funny you should mention that. I was just thinking, looking at those Sigma 8-16 images how much I worked on each one of them. I spent more time on some of those images than I often spend on 10 images. But when you get it right the results were worth it. You say aggressive, I say long and tedious.

Maybe it's because the field of view is so wide, you almost always have some bright sun and deep shadows in large areas of the image, and you really have to use the brush tools to custom PP different parts of the image, but, is it the lens optics or the extremely wide FoV, who's to say?

A couple of images from that series are hanging on my wall.

[maw]

Thanks for those links. Very useful. Mind you, I came here looking for a 15mm and now it appears that I also NEED a 70mm LTD!

Hi Theov39,

Perhaps now you have the most confused mind than before, I bought the lenses a little at a time and weighing their use well.

The 15mm f/4 is great for large spaces, for street-photography and even interiors in essence for travel, also is light and small, like all limited.

The 70mm f/2.4 is a beautiful lens, lends itself well for portrait and environment photos given the brightness of 2.4. I'll put two links to the two lenses so that seeing the images you can choose carefully.

SMC 15mm Limited

SMC 70mm Limited

[aslyfox]

Resistance is futile. You need to have both!

some folks do seem to like the " limiteds "

the limiteds do they live up to the reputation and why - Page 10 - PentaxForums.com

and some folks do seem to like the " * " lenses as well

Pentax * lenses do they live up to the reputation and why - Page 4 - PentaxForums.com

[maw]

Funny you should mention that. I was just thinking, looking at those Sigma 8-16 images how much I worked on each one of them.

Hi,

Previously I wrote that I have had for some time the Sigma 8-16mm f/4.5-5.6 DC, which I then sold because of the inability to use filters and for the overall dimensions.
This lens are really excellent, but I think that after a little use you feel the need to return to a more normal vision.
Reading I remembered some of the reviews I had read and maybe they may be interest you and the pentaxians or anyone who loves photography.

Test 1 Sigma 8-16 HD

Test 2 Sigma 8-16 HD

[Theov39]

Hi Theov39,

Perhaps now you have the most confused mind than before, I bought the lenses a little at a time and weighing their use well.

The 15mm f/4 is great for large spaces, for street-photography and even interiors in essence for travel, also is light and small, like all limited.

The 70mm f/2.4 is a beautiful lens, lends itself well for portrait and environment photos given the brightness of 2.4. I'll put two links to the two lenses so that seeing the images you can choose carefully.

SMC 15mm Limited

SMC 70mm Limited

Thanks Maw. That is very helpful.

[Theov39]

Thank you everyone for your very helpful advice.

Based on your advice, I have now bought a very nice like new Pentax HD 15mm I was lucky enough to find at a reasonable price.

Can't wait to take it out and see what it can do.

[Kerrowdown]

Wish they made one for FF

They did... my “Mistress" (Pentax-A 15mm F3.5).

[aslyfox]

Thank you everyone for your very helpful advice.

Based on your advice, I have now bought a very nice like new Pentax HD 15mm I was lucky enough to find at a reasonable price.

Can't wait to take it out and see what it can do.

Looks like you have a winner

But now you are proof of what some say:

that the " limiteds " are like that old potato chips commercial:

You can't stop at one

BTW

You have a future choice if you get another limited - smc or hd

HD vs. SMC Pentax Limited Primes Review - Introduction | PentaxForums.com Reviews

[jatrax]

They did... my “Mistress" (Pentax-A 15mm F3.5).

I've actually thought about acquiring one. The only thing that stops me is that there are none available in general and the odd one that shows is just a bit expensive

I really valued the DA 15mm for its ability to produce sunstars shooting right into the sun with no flare. What I would like is the same field of view on the K-1 with the great sunstars and no flare. And perhaps keeping the size about the same would nice as well.

Any thoughts on how the A 15mm f/3.5 does in those conditions?

I suppose I'm really looking for around 20mm with awesome sunstars.

[lesmore49]

I've got a 21mm Limited, I like it. Instead of getting a 15mm Limited, which I thought about, I bought a Pentax 12-24 and I'm glad I did. This is a great lens.

But do I think I made the right decision getting a ASP-C 21 mm and then a ASP-C 12-24...or would I have made the right decision getting a ASP-C 15mm Limited ?

Now, with my full frame Pentax K-1, I think not.

I don't want any lens that I purchase now, to be just an ASP-C lens...it also has to be completely good for full frame and ASP-C. I know my 12-24 works ok from 18-24, but I would prefer it to work ok from 12-24 on my K-1. Could be wrong but I think the Sgma 12-24 was/is a full frame lens, not sure if it was available as a K mount.

Maybe back in the 2007-2012 period, I should of got a full frame lens that would of worked well with both my ASP-C and full frame bodies. Back then, around that might of been me seeking out previously owned, film era FF 20 mm lenses and other wide angle FF lens.

So my advice, be careful what lens you buy. If you don't have a full frame Pentax body yet....but are thinking about it as a future consideration....

[maw]

Thanks Maw. That is very helpful.

I'm happy to have partly helped you make your choice, but as Aslyfox says "that the limiteds are like that old potato chips commercial", what will be the next step?

Congratulations, Mario

[Kerrowdown]

Any thoughts on how the A 15mm f/3.5 does in those conditions?

Well, my "Mistress" has indeed served me well over the years, Field of View is on Full frame: 111° Diag, 100° Horiz, compared to the HD Pentax-DA 15mm F4 ED AL Limited on a APS-C: 88° Diag, 77° Horiz, the difference is massive.

SMC Pentax-A 15mm F3.5 Reviews - A Prime Lenses - Pentax Lens Reviews & Lens Database

I suppose I'm really looking for around 20mm with awesome sunstars.

Again I've been very happy with the performance of my "Good Lady” (Pentax-A 20mm F2.8).

SMC Pentax-A 20mm F2.8 Reviews - A Prime Lenses - Pentax Lens Reviews & Lens Database

[jatrax]

Again I've been very happy with the performance of my "Good Lady” (Pentax-A 20mm F2.8).

I was able to acquire a Pentax A 20mm f/2.8 with original case and hood last fall. I have not yet had a real chance to test it (her?) out. Field of view should be 94° so a little wider than the DA 15 on APS-C. If the sunstars are adequate I will be happy. Being in Oregon we generally do not see the sun from November through May so no opportunity to test until spring.