[RICHARD L.]

I found a nice, like-new copy of the Pentax FA 20 mm f/2.8 that I use for architectural purposes on the K1. It never fails to produce excellent pictures. It cost 500 US$ when I bought it.



Cap-de-la-Madeleine Basilica, QUEBEC. K1 + FA 20 mm f/2.8 on tripod, 30 seconds @ f/11. I had to ask people to "thread lightly" and to wait a little not to intrude in my picture.

[AlwaysAl]

Having been bitten by the bug that favours autofocus lenses design/built for the new body technology, opted for the 15-30 for use with the K-1. It is, as Texandrews has stated, a "chunk" but performs well. Initially, got the 28-105 (a solid performer) and this newest addition fits nicely under that range. With my aps-c bodies, had/have a Sigma 10-20 that fit the purpose nicely and was looking for something similar when the 15-30 was acquired (it fits the bill).

[northcoastgreg]

I want something that does landscapes very well, but brings forth a beautiful character - not just sharpness, but a wow to a picture.

Now I have the DA 15 (which I've only used on APS-C) and the M 20/4, the FA 20-35, and the DFA 15-30 (all of which I have used on the K-1). Now the tricky thing here is to establish what it is about the DA 15 that "brings forth a beautiful character." Is it the "rendering"? But the rendering, I would contend, is very subtle, and it isn't plainly obvious that DA 15 renders all that differently from the FA* 24 or the M 20/4 or any other classic wide angle lens. If you have a very sharp eye, perhaps you'll notice subtle differences. But most Pentax prime lenses render pretty well and I'm not sure that's the main issue. I suspect the real difference between the DA 15 and FF equivalents like the M 20/4, FA 20/2.8, K 20/4 would be in color rendering and lens contrast. Those differences, in any case would be a lot more noticeable. The FA* 24 should render beautifully. After all, it's a Jun Hirakawa designed star lens. But however it might render, you're never going to get the same colors, or even the same level contrast, out of that lens than you will from the DA 15. The FF ultra-wide angle lenses that will get you closest to the DA 15's color and contrast will be the DFA 15-30 and the DFA 21 Ltd.

Now I wish I had some samples of the exact image taken with the DFA 15-30 and the DA 15, but I don't have any such images. This is about as close as I have: two images of the String Lake in Grand Tetons NP taken years apart. First, with the DA 15:



And the DFA 15-30 @15mm on the K-1:

[Digitalis]

I plan on getting FA 31 and FA 85 1.4.

In your position I'd strongly recommend the FA31, it's an extremely versatile limited lens that won't limit you.

Landscape:


Pentax K-1 - FA31 Limited



Pentax K-1 - FA31 Limited


Portraiture:


Pentax K5IIS - FA31 Limited



Pentax KP - FA31 Limited



Street photography:

Pentax K10D - FA31 Limited


Pentax K5IIs - FA31 Limited

I am considering holding out for the new DFA 21 2.4.

As a former owner of the FA15mm f/4 Limited (I replaced it with the optically superior Sigma 8-16mm f/4.5~5.6 in late 2012) I can say that the D-FA21mm f/2.4 is basically a DA15mm f/4 on steroids* and a really fun lens to work with on both APS-C and full frame.


Pentax K-1 SMCP-HD D-FA21mm f/2.4 ED ASPH Limited

The close focus ability of this lens makes it a lot of fun and the Bokeh you get from using its close focus ability is very pleasing.


Pentax K-1 - SMCP-HD D-FA21mm f/2.4 ED ASPH Limited

* Flare resistance isn't quite in the same ballpark, however the Dfa21 is optically superior to the DA15mm f/4 in many ways.

---

Last edited by Digitalis; 01-14-2022 at 06:54 PM.

[UncleVanya]

Wild option:
Da 12-24 or da* 11-18 - the longer end works in full frame. On the 12-24 you get about 20-24mm or wider. On the 11-18 you get 17-18 if I recall. These ranges are in full frame mode. Your da 15 has about the same coverage as a 22mm on full frame.

[cowlitzJim]

FYI.. I put the 18-50re on my k-1 and shot in square mode. Image width is equivalent to 28mm or slightly wider, with no vignette. WR and silent focus are nice, but full sensor shots vignette to ~30mm.

[acoufap]

Wild option:
Da 12-24 or da* 11-18 - the longer end works in full frame. On the 12-24 you get about 20-24mm or wider. On the 11-18 you get 17-18 if I recall. These ranges are in full frame mode. Your da 15 has about the same coverage as a 22mm on full frame.

DA*11-18 with hood 16-18mm, without hood and filters („naked filter thread“) also 15mm.

[turbo_bird]

I'm a fan of older glass, and can recommend the old SMC K 24 f3.5 as well, if that's wide enough for you. I really like using it on my K1. I also recently got an F24-50 f4 zoom that I like. I haven't played with the zoom lens much yet, but so far I'm liking what I've been able to capture with it.
This was taken with the K 24


And this is from the 24-50 @24 mm.


I haven't had my K1 for long, so I'm looking forward to using them both in the summer as well. I don't often shoot that wide though, so they won't see a ton of use from me. I used the 24mm more often on APSC bodies.
Kristian

[Shedking]

Irix has just announced a 21mm cine lens, but not yet announced any Canikon or Pentax mount versions. I have the excellent 15mm Blackstone and would be very interested to see how a modern, weathersealed MF Irix 21mm stacked up against the D-FA.

https://irixlens.com/cine-lenses/21mm/

[5r82]

No one seems to mention Samyang 20mm f1.8. Looks like a nice modern and a very fast lens. I wish I could have experience with Pentax K, M or A series 20mm lenses but I don't. They all seem like beautiful lenses.

On the other hand, my experience is with Tamron 24mm f2.5 and CZJ 20mm f2.8. Both of my reviews you can find here:

Tamron Adaptall-2 24mm f/2.5 (01B) Lens Reviews - Tamron Adaptall Lenses - Pentax Lens Review Database

Carl Zeiss 20mm F2.8 Flektogon MC Lens Reviews - Carl Zeiss Lenses - Pentax Lens Review Database

[zbrueningsen]

In your position I'd strongly recommend the FA31, it's an extremely versatile limited lens that won't limit you.

As a former owner of the FA15mm f/4 Limited (I replaced it with the optically superior Sigma 8-16mm f/4.5~5.6 in late 2012) I can say that the D-FA21mm f/2.4 is basically a DA15mm f/4 on steroids* and a really fun lens to work with on both APS-C and full frame.

I admire your input and work. I was actually looking at your DFA 21 pictures a few days ago. I had a feeling that the DFA 21 was like the better version of the DA 15 - and you confirmed that. I definitely am in the crowd that the DA 15 controls my mind.

---------- Post added 01-15-22 at 07:17 AM ----------

On the other hand, my experience is with Tamron 24mm f2.5 and CZJ 20mm f2.8.

Your pictures with the Zeiss are pretty stellar. And the Tamron pictures are pretty good also. I definitely will keep those in mind.

---------- Post added 01-15-22 at 07:21 AM ----------

Irix has just announced a 21mm cine lens, but not yet announced any Canikon or Pentax mount versions. I have the excellent 15mm Blackstone and would be very interested to see how a modern, weathersealed MF Irix 21mm stacked up against the D-FA.

So my one issue with the Blackstone (which was on my list previously), is the filter size/system. I'm not real excited about an enormous filter or a gel filter system. Seems like additional work?

I've seen the work the Iris 15 does and I've been very impressed. The 21 looks great that they are doing but the price point is so close to DFA 21 (the cine 21), that I definitely would go with DFA if I am spending that money.

Size and filter systems is where I got off the bus with the Irix.

---------- Post added 01-15-22 at 07:27 AM ----------

You all have given great suggestions and some of the work displayed is incredible. I think you have helped me figure out why I had the list I did (and maybe this furthers the discussion):
I do value compactness. I do value Pentax's primes rendering. I'm not quite to sacrificing quality of picture for the sake of compactness (that's the K vs M argument).
I have flirted with the Rokinon line also and have used their 35 and 85 and for the money they are hard to beat. But they are both pretty large.
It's hard to deny the 15-30's output. Some of those pictures rendering and quality are top notch. My resistance is it's size.
If I did the APS-C "limited range" from some of those lenses I would probably go back to the 20-40 as I enjoyed that and it has a decent range on full frame.

One issue someone brought up about the DFA 21 is filters. Is there an issue with putting on filters (ND or CPL) with the DFA 21? If so, what is the work around? This would be waterfall/water shots that would be impacted by this.

---------- Post added 01-15-22 at 07:30 AM ----------

I'm a fan of older glass, and can recommend the old SMC K 24 f3.5 as well, if that's wide enough for you. I really like using it on my K1. I also recently got an F24-50 f4 zoom that I like. I haven't played with the zoom lens much yet, but so far I'm liking what I've been able to capture with it.
This was taken with the K 24


And this is from the 24-50 @24 mm.


I haven't had my K1 for long, so I'm looking forward to using them both in the summer as well. I don't often shoot that wide though, so they won't see a ton of use from me. I used the 24mm more often on APSC bodies.
Kristian

The SMC 24 3.5 is in my Ebay cart right now. As the "lower tier" out of this group. I've read that all the 3.5s from the K series were high performers. 24, 28, and 35.

---------- Post added 01-15-22 at 07:38 AM ----------

Now I have the DA 15 (which I've only used on APS-C) and the M 20/4, the FA 20-35, and the DFA 15-30 (all of which I have used on the K-1). Now the tricky thing here is to establish what it is about the DA 15 that "brings forth a beautiful character." Is it the "rendering"? But the rendering, I would contend, is very subtle, and it isn't plainly obvious that DA 15 renders all that differently from the FA* 24 or the M 20/4 or any other classic wide angle lens. If you have a very sharp eye, perhaps you'll notice subtle differences. But most Pentax prime lenses render pretty well and I'm not sure that's the main issue. I suspect the real difference between the DA 15 and FF equivalents like the M 20/4, FA 20/2.8, K 20/4 would be in color rendering and lens contrast. Those differences, in any case would be a lot more noticeable. The FA* 24 should render beautifully. After all, it's a Jun Hirakawa designed star lens. But however it might render, you're never going to get the same colors, or even the same level contrast, out of that lens than you will from the DA 15. The FF ultra-wide angle lenses that will get you closest to the DA 15's color and contrast will be the DFA 15-30 and the DFA 21 Ltd.

Both pictures are terrific, but the DA 15 was the one that was my favorite. It just is so vibrant. UGHHHH. I asked my wife which picture she liked better and she said the top one. While the top one is a better scene, but it is just something about it. Some days I just wonder, why not get a K3ii or K70 and pixel shift on that sensor. My favorite landscape pictures are from my K3 and DA 15.

This is my 1 pixel shift landscape - DA 15 + K1 Bear Lake Beckenridge, CO

[Shedking]

The 21 looks great that they are doing but the price point is so close to DFA 21 (the cine 21), that I definitely would go with DFA if I am spending that money.

Your points about size and filter systems are very valid, but Irix's pricing is very competitive.

The Irix 15mm cine is 1195 euro in the Irix official store, with the 15mm Blackstone priced at 725 euro and the 15mm Firefly at 475 euro. The 21mm cine has launched at the same price as the 15mm cine, suggesting that a 21mm Blackstone could be less than half the price of the DFA 21mm. A Firefly version might therefore cost only a third as much as the DFA.

[wadge22]

I really feel like I want the SMC K 20

Maybe that's what you should go for then...? I see a few on ebay now, so it's not unobtainably rare, or anything. Seems like maybe you should go with your gut, rather than talking yourself into more expensive options.

I only have the FA*24, and don't really have much to say from my experience. It seems fine. I will say that they are available at some pretty attractive prices these days, maybe because of how many other options are around.
I don't shoot a lot of wide shots. When I do I could probably be using my phone, honestly, since they're basically just travel snapshots (for me). I've considered changing to the M 20/4 just for it's compactness.

[northcoastgreg]

I really feel like I want the SMC K 20, but I haven't seen enough field samples.

That's kind of the difficulty with that lens. It's hard to know what the images are going to look like. Now I have seen quite a few images from the other Pentax legacy 20mm lenses, and I'm most impressed with what I've seen from the FA 20, which has the beautiful color rendering of the FA series (which tends to be even more striking among the primes than among the zooms). The A 20, which is optically the same as the FA 20, nonetheless produces a slighly more muted look when it comes to color rendering (the fine tuning of the SMC coatings seems to be different among the A, F, and FA series of lenses, leading to slightly different color rendering among the three series). Among these lenses, the M 20 is a bit of a sleeper. It's maybe a little less sharp than the others and never is quite sharp in the corners or far edges. Nevertheless, it renders quite beautifully and depending on what kind of light you throw at it, is capable of producing beautiful images on the K-1:

At f22:



At f16:



At f4:



At f16:



At f16:

[Digitalis]

the M 20 is a bit of a sleeper. It's maybe a little less sharp than the others and never is quite sharp in the corners or far edges.

In my comparison between the new DFA21 and existing 20mm lenses for Pentax* the M series lenses M20 f/4 and K24 f/2.8 can't compete, optically the DFA21 is quite a bit sharper than they are.


*On my list: the FA*24mm f/2, Voigtlander 20mm f/3.5 Color Skopar, SMCP-K 20mm f/4 Vs the DFA21. I have been working with the Voigtlander and it certainly feels like the odd one out among Pentax primes. They Samyang 20mm f/1.8 has been suggested for the comparison but no store has them in stock in my area and I'm really not willing to risk the runaround with the (allegedly) lacklustre Samyang QC considering my luck with third party UWA lenses. I really struck it lucky with Sigma Japan ( their resolution to the 8-16mm f/4.5-5.6 debacle was impeccable) but I think if I didn't have hard data from my optics bench, they would have given me the cold shoulder like everyone else.