[yusuf]

I recently noticed at-least two sale post for A15/K15 is the market at the price twice of DA15 Ltd. I am not familiar with these lenses but DA15 is quite a wannabe lens and based on past discussions, probably a better lens. Just wondering what makes A15/K15 so expensive compared to DA15? Rarity factor?

Yusuf

[selar]

I asked the same question a few months ago and was told it was because they were collectors items.

Plus they are full frame. The widest rectilinear full frame Pentax made lenses available.

[SteveM]

I would expect the Takumar version to be much more expensive than the versions we have seen here. I sold my first, then regretted it and finally found a replacement. $1000 US is what I paid both times.

Why?

1) History

from the Dimitrov website....

At Photokina 1972 Pentax and Carl Zeiss showed prototypes of a 15mm f/3.5 rectilinear lens with remarkably similar optical designs. In fact, the only noticeable difference was that Zeiss' lens employed only spherical optics while Pentax's made use of one hybrid aspherical element. In 1974 both prototypes became production lenses. Pentax's SMC TAKUMAR 1:3.5/15 was virtually identical to the prototype from 1972 whereas Zeiss's lens used the same optics but employed floating elements, probably for improved close-performance.

Here the story gets really interesting and a bit unclear. Pentax was of course proud of their aspherical optic, and did mention it in some early lens brochures. However, shortly afterwards they decided that the production of the aspherical element is too expensive, and started developing an alternative optical formula based solely on spherical surfaces.

2) Build quality

Legendary build quality and it is an unusual design, including built in filters.

3) Performance

Debatable - I have the aspherical version in K mount (rare). I have never tried the DA15, but I would presume it would be sharper. I like contrast and other qualities of older glass however. Flare can be an issue with the K15.

If you are solely buying a 15mm lens for performance on a crop sensor, I'm not sure the K15 would be the best choice. I love mine though.....

[DanielT74]

I find the K 15/3.5 to be extremely sharp even wide open. It also handles distortion and vignetting better than the DA 15mm. Where DA15 would be superior is flare. DA 15 is the flare king par excellence!

K15/3.5 just produces a great feel of depth and microcontrast. Also pretty nice bokeh if you get really close to the subject.

PS I am not convinced that there were two different designs of the 15/3.5 but I will have to do some more testing.

[hoanpham]

It's all about history and limited number of production, especially the AL version. This lens might be the reason I stay with Pentax and still waiting for a full frame body. I have this lens 30 years, awesome on film. The status is very similar to Nikon's 14mm.

Price has not been dropped much since 30 years ago. Compare to money value of old days, would you use a month salary (or more) to buy one lens? However, it's a kind of waste of value when mounted in a crop sensor. I started before AF era, and simple look at this lens as best optical available that day. Unlike other 3rd parties brands, the lens does keep a fair value.

I can keep this lens for long time, and also the K50f1.2 for low light, the K28shift for specialty purpose, K30f2.8 for sharpness, and more in K series. It's a safe bet when I buy lenses.

IMO, the 15 Ltd is far better optical and cheaper. Once you buy one of the K15AL, you are collecting history objects and should look at the lens as an investment. I am not sure if Pentax made only 100 copies in K mount, but mine is in M42 mount. I used mine a lot more before than now.

[DanielT74]

Hoan, why do you say the 15ltd is better optically? Do you have images to compare?

I only tried 15ltd for a short time but was not that impressed. I like DA12-24 better and the 15/3.5 better than the 12-24mm.

[wlachan]

The original FF 15/3.5 was an interesting lens. From what I can recall, it was developed together with Zeiss (also 18mm and some other lenses I don't remember) in the 70's, then the relationship ended and they went their ways. The Pentax 15mm is high on flare control but weak on light-fall-off and edge/corner sharpness even stopped way down. The Zeiss is a little behind on flare control but better on light-fall-off and edge/corner sharpness (so were the Leica & Nikkor). I had the K15/3.5 (non-AL) for a short while and the 2 weakness were quite severe on film imho. It was great for dramatic effects but not suitable for scenery. Nailing the focus on digital was almost impossible and resulting in soft results. Today, any FF 15mm are collector's items. The Pentax one has been carrying the 1k price tag for many years. For actual shooting, the DA12-24/4 will be far superior imho.

[DanielT74]

Here are some pics with the old 15/3.5 taken wide-open today:



100% crop:



backfocused this one but still worth taking a look I think for what this lens can do:





I will try to do some direct comparisons with the DA12-24mm tomorrow if anyone is interested. I expect the K15/3.5 to give it a real run for its money..

[wlachan]

These look really great. I wonder how you managed to nail the focus. Did you use split image screen? I am still struggling to produce decent results with the DA14 which has inconsistent edge/corner sharpness.

[Lowell Goudge]

I wanted a ~15mm prime for years, and ultimately bought the samyang 14F2.8 for about 1/3-1/2 the price of the K15/3.5.

I would love to have comparison shots, if someone wants to loan me the K15

[Adam]

I would say it's just because they're rare and full-frame (there aren't many lenses that are that wide).

On digital, the DA15 puts the K/A lenses to shame, though.

[DanielT74]

These look really great. I wonder how you managed to nail the focus. Did you use split image screen? I am still struggling to produce decent results with the DA14 which has inconsistent edge/corner sharpness.

Yeah, I have the katz-eye split image focusing screen on my k20d but I find focusing with ultrawides pretty easy especially if you stop down a bit (these ones were wide open).

Lowell, any time you are in Melbourne, you can borrow any lens of mine you like.

I would say it's just because they're rare and full-frame (there aren't many lenses that are that wide).

On digital, the DA15 puts the K/A lenses to shame, though.

Well, I am not convinced, Adam. Do you have comparison images?

I don't have the DA15 anymore but DA12-24 is in the same league, some argue better and I am not sure if it produces better IQ than the K15. I guess a comparison thread is called for. A duel between legacy and modernity!

[Lowell Goudge]

I would say it's just because they're rare and full-frame (there aren't many lenses that are that wide).

On digital, the DA15 puts the K/A lenses to shame, though.

te samyang 14mm F2.8 is ful frame, and although there is some barrel distortion, the control of CA is excellent.

It is a real fun lens on my PZ-1 with B&W film

[Lowell Goudge]

Lowell, any time you are in Melbourne, you can borrow any lens of mine you like.

Daniel

Be careful with invitations like that.

Seriously, I have never been down under so it is on my to do list

[SpecialK]

Do you have comparison images?

There's a whole dedicated thread.

https://www.pentaxforums.com/forums/lens-clubs/86234-15mm-limited-controls-my-mind-club.html