[Sandy Hancock]

I think all of these changes would be easily achievable without any significant impact on size or cost.

I think you're dreaming.

If you want faster, better corrected lenses you will pay more for a bigger lens. They would cease to be DA Limiteds.

[StarTroop]

If close focusing is really a requirement, and the DA 70 just has to be the lens to use, why not grab a good macro filter and keep it in your bag? I get liking not having to go for that kind of solution, but they're not a big deal to use, I think.

For me a lens in the 20mm to 30mm range, on a crop body, is so great for general carry. Not having a faster aperture makes it more challenging to obtain subject separation from the background. The Canon 24mm f2.8 pancake seems about perfect for this kind of thing. I'm not going to say it renders as nicely as the DA 21 but that's really more like what I'd want. It does have good flare resistance as shown in the shots shared previously in this thread.

This is all just my own opinion anyway. Lately I've been interested in getting an FA*24 so obviously I'm okay with giving up small & light for other features.

I believe that with Canon's 1.6x crop, the 24mm works out to being more like a 40mm equivalent rather than Pentax's 21mm, which functions as a 31mm equivalent, which is actually a pretty noticeable difference in FoV. I've mentioned elsewhere that the DA Ltd line is ripe for a 28mm lens, which would provide a 43mm equivalent FoV, but in the absence of that, any of Pentax's existing older 28mm f/2.8s would pretty much provide the same function as Canon's 24mm, at an only slightly larger size.

[mikesbike]

That Fuji lens is a marvel at the wide end. Here's Lenstip's findings: Fujifilm Fujinon XC 15-45 mm f/3.5-5.6 OIS PZ review - Image resolution - LensTip.com

WRT to the DA15, the copy I'm using is the most evenly sharp of the 3 I've owned, so there's definitely some variability out there. Also, my standards might be lower than yours.

Here's a 100% crop from the extreme lower-left corner:

This to me is impressive, as well as the surprisingly low distortion of such a wide angle lens in such an amazingly small body. Corners are rarely, if ever, very important for content compared to edges and the rest of the image. The other wide angle lenses I have, such as the Pentax DA 12-24mm f/4 and the Sigma 10-20mm f/3.5 can outperform the DA 15 f/4 in terms of wide open edge sharpness and even in terms of distortion at 15mm, but at the cost of much larger size. There is no way I ever thought I'd someday be able to put such a capable, beautiful lens of such a wide angle into the front accessory zipper compartment of my belt holster-type camera case, where it is so unnoticeable I forget it is there until I need it!

Compact size with very good to excellent imaging quality has long been the design attributes of Pentax Limited lenses.

Within a certain FL range and corresponding FOV, It has been possible for the APS-C oriented DA series to be made smaller than the FA series. But here we do see both compromises of sorts, and some FOV range missing, due to the impossibility of duplicating what some FA models can accomplish on a FF body. It would not be possible, for example, to replicate the FOV and aperture range of the FA 43mm f/1.9 on a FF body and still have a lens of comparable size. Ditto with the FA 31mm f/1.8 while not as small as the FA 43mm, is really compact for what it is. The DA 21mm is indeed smaller, but not anywhere near f/1.8 either. Look as the size of a FF 24mm f/1.8 or even f/2 and it is easy to see a DA version would cut some size but would still not be as small as the FA 31mm and also not at the 21mm equivalency.

---------- Post added 10-16-19 at 06:44 PM ----------

I think the KP's role is to be the optimal camera for the Ltd's.

Does a great job of it, too.

[Paul the Sunman]

Does a great job of it, too.

It will be interesting to see how long after the release of the K-new that a KP-replacement comes along and inherits some of the new technology.

[Madaboutpix]

I was already beginning to kinda give up on my smc DA15 - given all the love-or-hate polarity over this lens, and a number of occasions where I hadn't used the lens to its best effect - but then, this year, I made a conscious effort to deepen my learning of its quirks and do more shooting with it.

This acted as a reminder to myself that the DA15 wasn't conceived to excel in laboratory test chart comparisons but to shine in real-world photography, in the hands of photographers who appreciate the crisp contrast and gorgeous colours or b/w tonality this lens can give them in such a small and unobtrusive package. Yes, it does have pretty severe field curvature, but that can be mitigated to some extent by a solid focus technique and sometimes compositional choices. I suspect, even if I actually won that super-awesome DA*11-18 on these forums, I would still sometimes go with the DA15, for its form factor, the sheer fun of shooting it, and for the simple fact that it gives me images like those below (full-res here: London 2019 - Marc).

Another thing that I love about my DA15 is that I rarely feel the need to correct for distortion in post, as what residual distortion there is, is straightforward barrel type (rather than "mustache" type) and often even helps to make images look more natural.

[luftfluss]

Of course, it did take research from Photography Life to discover Fuji do this with ISO:

Does Fuji Cheat with its Sensors?

That's outdated news, Clackers Over the last few years Fuji's ISO ratings have become closer to what us Pentax users expect...

Indoors, under typical incandescent lighting, color balance was quite warm using the Auto setting, with a fairly strong reddish cast. Results with the Incandescent white balance setting were also very warm, with a strong yellow/orange cast. The Manual white balance setting was quite accurate, though. The Fuji X-Pro2 required +0.7 EV exposure compensation here, while most cameras need about +0.3 EV for this scene. Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.

- Imaging Resource

My own experience is in line with Imaging Resource's, noting about 1/3 stop deviation in exposure between the FUji X-T20 and Pentax K-70.

[Jonathan Mac]

My two cents, take as such; those are all optical design changes and/or changes in how the lens elements are made (machined instead of molded) to reduce surface irregularity and such save for adding a focus limiter to the DA 35.

The DA 21 never made a lot of sense to me; it's like a 35mm lens on full frame but it's not fast and the magic happens when it's stopped down a bit from an already relatively slow max aperture. If it was a full frame I could maybe see an f3.2 max aperture as it would be a pretty wide angle lens. As it is, it's like, what is this for? A slow street lens? I know some folks have and really like it, I just don't quite get it myself.

Likewise, saying that the DA 15 needs to be sharper wide open, why? It's a landscapes lens in my mind (although I have used it to take group photos a couple of times) and will be used often at f8 or f11 which is where starburst magic happens anyway. What I would really like is for a WR variation on the SMC version with its straight aperture blades. Or better yet, seal it up even better to the AW level. And that would increase the size and weight but I'm cool with that.

As long as the lens is pretty sharp in the center wide open I don't really think there's an issue. I don't mind soft edges on an f1.x prime as long as the center is nice and sharp. Same really for any lens. I agree with Henri Cartier Bresson's famous quote; "Sharpness is a Bourgeoise Concept"

The big things that the 21mm have going for it are it's small size and, as long as flare doesn't creep in, it's ability to add sunstars. Until I got the 21mm I needed either the poorer-performing 18-55mm kit lens or the much larger and heavier Tamron 17-50mm f/2.8 for wide angle, and I now have the Sigma instead of the Tamron, which is even bigger and heavier. The 21mm is handy for social gatherings, though extra speed here would be nice, and as a landscape & cityscape lens. it's especially nice for night-time cityscapes.

The DA 15mm isn't always shot stopped down. I've used it in cathedrals with limited light and had to accept that the corners would be soft or face making the whole image much noisier by stopping down and upping the ISO. Being sharper wide open would help there a lot.

* * * * *

It seems that adding WR is the most-desired thing for the Limiteds and I can't argue with that, even now that I have the 16-85mm, if my Limiteds were WR I'd much prefer the primes to the zoom.

[pres589]

I've shot the DA 15 wide open before as well, usually for a group shot, and as long as no one is standing on the edge of the frame it's not so bad. My point was really, if you shoot to the lens's strengths and come prepared, the DA 15 produces wonderful images. Also agree/understand that shooting somewhere like in a gym or cathedral will be a real challenge with the DA 15 unless you don't mind using a tripod or similar and people are going to show motion blur due to long exposure times.

[house]

I suspect, even if I actually won that super-awesome DA*11-18 on these forums, I would still sometimes go with the DA15, for its form factor, the sheer fun of shooting it,

Yep, I would do the same for sure. As I've said it's great for some stuff.

[TerryL]

Tweak the design to prevent wobble over time. All my limited wobble a fair bit and could be a bit more robust.

I wouldn't change any of them optically. For the size they are well judged. I'm annoyed with my da 15 but I realise I should just get another, non limited, lens. But there isn't a wide angle prime for pentax FF or apsc. I would consider FF if there was a good AF wide/uw prime.

The Sigma 10-20 f/3.5 is nice on.

[luftfluss]

The Sigma 10-20 f/3.5 is nice on.

That Sigma is not a prime, it's a zoom.

[clackers]

That's outdated news, Clackers Over the last few years Fuji's ISO ratings have become closer to what us Pentax users expect...

Their problems don't end there, LF … this obsession with trying to compete by rigging everything in algorithms rather than real optics leads to this …

X-Trans: The Promise and the Problem

The GFX series shows they know it doesn't work!

[howieb101]

Their problems don't end there, LF … this obsession with trying compete by rigging everything in algorithms rather than real optics leads to this …

X-Trans: The Promise and the Problem

The GFX series shows they know it doesn't work!

I've first hand experience of the waxy skin with an X-E1.

Fujifilm also apply a high contrast curve that reviewers seem to love but loses detail.

I am still not convinced about X-trans.

They are nice looking cameras though.

[MikeyBugs95]

I'd like to see some WR. Maybe a DC or other smallish motor as well. They did it in the 20-40, they can do it in the rest of the DA Limiteds while keeping a larger but still very compact size. Come on, Ricoh! Make the 35 Limited the first Macro lens in K-mount with an in-lens AF drive!

DA 35mm - A focus limiter. Definitely no changes needed in the optics here.

An interesting idea but how would it be done on a lens so small? I can imagine an implementation that is reminiscent of an aperture ring on classic film lenses. A rotating ring near the base of the lens that rotates and adjusts the focus limiter from full, infinity to 0.3 meters, and 0.3 to 0.139 meters. Maybe even include a focus lock at one end to lock focus at the current position disengage the screwdrive or focus motor. Of course that means that they'd no longer be able to include the nameplate at its current spot at the base the lens body.

[zapp]

DA Limited land is Limited :-)
Many other things will happen before someone will consider improving these lenses.