[Cerebum]

The purpose of the DA 15 is simple; to take pictures you can't take with the other lenses in your bag. Your photography with an UWA lens will be limited if you have to compensate for flare, your photography will be limited if you need to pack a lens with an oversized front element when you are out for a casual walk, your photography will be limited if you have to wait for the right light to get that certain "sparkle" your eyes can see, but your camera can't seem to capture. The DA 15 should be considered an Unlimited lens; it rewards experimentation and with practice, will let pikers like me take pictures that make strangers say "wow!" Without being obviously different, the DA 15 is not like other lenses. It is truly fun to use.

Wow!

I have had it out for one walk and straight away I can see how tremendous it is. All the benefits of the 10-17 without the pitfalls of flaring and distortion. I loved my month with the 10-17 and can't wait to sic the 15mm in feb. We don't have mountains but we do have a canal, a nature reserve with standing stones, a castle and lots of old buildings.

Regarding limiteds, it never occurred to me (I can be a bit slow) that the DA limiteds are a "set"! You have excellent ultra wide, wide, standard macro, standard and portrait lenses in one neat series! I may never shoot vintage glass again! (Except for my tomiokas ... And if I want swirly bokeh..... Oh, then there's my lovely alloy tessar .... Oooh the takumar 35mm) OK, maybe I will lol.

---------- Post added 01-16-21 at 02:01 AM ----------

I guess it is the combination of the diffraction spikes with such little flare that I like. You're shooting at 15mm, so it isn't as though those spikes should dominate an image, but it does feel to me like they can draw attention to one part of the image or another. I guess I feel like it is anything else in photography -- very nice when used carefully, but not so great when used over much.

I keep coming back to that barn image. Stunning

[Jonathan Mac]

When people say the DA 15 isn't very sharp, and then someone shares an image like that iced greenery taken at f4.5 which is "just off" wide open... well, I call shenanigans on all that.


Great shots, hope the lens treats you sell, Cerebum.

Anyone who says the 15mm isn't sharp stopped down has a bad copy, whether generally soft or due to de-centring.

[normhead]

Anyone who says the 15mm isn't sharp stopped down has a bad copy, whether generally soft or due to de-centring.

Or, poor shooting technique, not appropriate to the lens.

It amazes me that in this day and age people would claim a lens is not sharp. My 20 year old lenses are sharp. Their handling of flare, CA or purple fringing, etc. may be suspect, but not sharp? Highly unlikely.

My 40 year old Vivitar 135 2.8 is not sharp. My 25 year old Pentax 28-200 is not sharp. My FAJ 18-35 is not sharp. Reduced in size to 3840 x 2160 for 4k TV viewing, they are all sharp.

Any lens designed with LD or aspherical elements is sharp. The 15 has both. Even heavily corrected lenses with neither of those elements like the F 70-210 are sharp. It's the CA and purple fringing that brings them down.

[pres589]

Anyone who says the 15mm isn't sharp stopped down has a bad copy, whether generally soft or due to de-centring.

And it doesn't need stopping down very far to reach maximum sharpness. Yet people here will still complain that "it's not a sharp lens".

From ephotozine's review of the HD version, tested with a K-5 IIs at https://www.ephotozine.com/article/hd-pentax-da-15mm-f-4-ed-al-limited-lens-review-23133

[house]

When people say the DA 15 isn't very sharp, and then someone shares an image like that iced greenery taken at f4.5 which is "just off" wide open... well, I call shenanigans on all that. .

I don't think anyone ever complained about the DA15 center sharpness. If they do they must have a faulty copy or extreme requirements. It's the edges and corners that suffer. Generally speaking close ups to mid ups look great. Most likely because oof hides the corner smearing. The contrast and colours really shine through and overtake any sharpness issues with those sorts of shots. I really like it for in context portraits and kids doing stuff in tough lighting.

This is the sharpness field map at DOMARK. It mirrors my experience with the lens. $546.95 at bandh

F8

F4


This is the Canon Canon EF-M 11-22mm f/4-5.6 IS STM at 14mm for reference (I just picked the first wide angle apsc lens I could find. this is a zoom...) $399 at bandh
F8


F4.5


The sharpness performance of the DA15 isn't very good. Many people don't need resolution and look for other qualities that might be more important for low res photography.

[kh1234567890]

Anyone who says the 15mm isn't sharp stopped down has a bad copy, whether generally soft or due to de-centring.

I would not dispute the centre sharpness of the DA15. What puts me off using it more is that AF with my copy on my K5ii can be a bit unpredictable - I tend to shoot hand held, centre spot focus and recompose.




My DA12-24 AF is OTOH spot on every time.

[Madaboutpix]

Much of the oft-bemoaned corner softness of the DA15 is actually down to field curvature, which in the case of this lens means that the edges of the focal plane bend towards the photographer, particularly at wider distances. And that field curvature also affects lab test results of the lens, given that they use two-dimensional test targets. LensRental's Roger Cicala has written a quite illuminating series of articles on field curvature (published in his own blog and on DPR), stressing the influence of your framing decisions if you want to make the most of such a lens. That is, a good-copy DA15 may actually be plenty sharp in the corners, but at distances that will puzzle many users.

[house]

Much of the oft-bemoaned corner softness of the DA15 is actually down to field curvature, which in the case of this lens means that the edges of the focal plane bend towards the photographer, particularly at wider distances. And that field curvature also affects lab test results of the lens, given that they use two-dimensional test targets. LensRental's Roger Cicala has written a quite illuminating series of articles on field curvature (published in his own blog and on DPR), stressing the influence of your framing decisions if you want to make the most of such a lens. That is, a good-copy DA15 may actually be plenty sharp in the corners, but at distances that will puzzle many users.

Yes field curvature is certainly part of it but not the whole story. It's not very sharp in the corners even with field curvature taken into account. When you're lucky enough to be able to fit the subject into the field curvature I'd say it approaches good enough. The smearing won't be distracting at web sizes (2048px)

Field curvature is not some theoretical issues though it means that in practice you can't take a long distance landscape photo without noticeable softness even at low res. Depending on what you shoot you can work around it or ignore it but it certainly limits the flexibility of the lens.

[BigMackCam]

Much of the oft-bemoaned corner softness of the DA15 is actually down to field curvature, which in the case of this lens means that the edges of the focal plane bend towards the photographer, particularly at wider distances. And that field curvature also affects lab test results of the lens, given that they use two-dimensional test targets. LensRental's Roger Cicala has written a quite illuminating series of articles on field curvature (published in his own blog and on DPR), stressing the influence of your framing decisions if you want to make the most of such a lens. That is, a good-copy DA15 may actually be plenty sharp in the corners, but at distances that will puzzle many users.

You beat me to it

Field curvature can be frustrating or occasionally useful depending on the scene (it's what challenges my acceptance of the HD DA20-40 at the long end). It can be especially troublesome when using centre point AF to focus and recompose, since the target will no longer be accurately focused. For off-centre targets, it's best to move the AF point...

[Madaboutpix]

Yes field curvature is certainly part of it but not the whole story. It's not very sharp in the corners even with field curvature taken into account. When you're lucky enough to be able to fit the subject into the field curvature I'd say it approaches good enough. The smearing won't be distracting at web sizes (2048px)Field curvature is not some theoretical issues though it means that in practice you can't take a long distance landscape photo without noticeable softness even at low res. Depending on what you shoot you can work around it or ignore it but it certainly limits the flexibility of the lens.

Not trying to argue away that the DA15 may not be the sharpest-corners lens around, nor particularly suited to certain kinds of pictures, but when you shoot it to its advantage it will turn out those kinds of images it is admired for. Let's not forget that every lens design brings compromises, and there is some price to be paid for that compact form factor and easy portability, I guess.

[BigMackCam]

Yes field curvature is certainly part of it but not the whole story. It's not very sharp in the corners even with field curvature taken into account. When you're lucky enough to be able to fit the subject into the field curvature I'd say it approaches good enough. The smearing won't be distracting at web sizes (2048px)

Field curvature is not some theoretical issues though it means that in practice you can't take a long distance landscape photo without noticeable softness even at low res. Depending on what you shoot you can work around it or ignore it but it certainly limits the flexibility of the lens.

Whilst it's true that corner performance of the DA15 isn't stellar, a lot of folks simply misunderstand the nature of a wide angle lens with optical rectilinear correction. The resulting stretching that appears most prominently in extreme borders and corners is easily mistaken for softness where fine detail is concerned, when it's a different thing entirely...

[house]

Not trying to argue away that the DA15 may not be the sharpest-corners lens around, nor particularly suited to certain kinds of pictures, but when you shoot it to its advantage it will turn out those kinds of images it is admired for. Let's not forget that every lens design brings compromises, and there is some price to be paid for that compact form factor and easy portability, I guess.

Absolutely. It's so tiny and nice to use you can't really expect top notch performance. It's quite expensive and very slow though so I think it could do better.

I do think that some of the appeal comes from people viewing very low res photos not very critically. For the longest time I thought I had a bad copy because everyone seemed so happy about the lens. So I started looking around to see how other copies performed. Most of the public images were (then, this might have changed) only available at extremely low resolutions, barely full screen on a laptop. After hunting down a few 24mpix images and then seeing the dxomark graphs I realised my copy is quite representative. Recent cameras are 24 mpix though and using lenses unable to take advantage of that is a bit of a waste.

Most people on this thread have pointed out the strengths correctly. For those willing to work around the weak edges or just tend to shoot center composed it will be a brilliant lens.

[Alex645]

Regarding limiteds, it never occurred to me (I can be a bit slow) that the DA limiteds are a "set"! You have excellent ultra wide, wide, standard macro, standard and portrait lenses in one neat series!

Very true. Hey Ricoh (or KEH), sell them in sets! Buy six for the price of five. Only choice is silver or black. Make it also a kit option with a new body.
Or create a Pentax Limited membership. With each new limited, your benefits increase on future purchases.

[Madaboutpix]

It's quite expensive and very slow though so I think it could do better.

Could it do better? If it was redesigned today, perhaps, though the laws of physics are still hard to beat. As for the price, that also pays for the adorable metal build, at least two kinds of specialty optical glass used, industry-leading coatings, a leather pouch, and whatnot. If I take all that together and the potential fun to be had in using it, plus a little profit for Ricoh Imaging, given that this lens is supposed to make them at least some money, I think the price is actually pretty reasonable. If a crop-shooting Pentaxian needs a corner-to-corner-sharp ultrawide, there's always the formidable DA*11-18 to be had. Actually, I wouldn't mind owning one of those, but so far I haven't been able to afford one ...

[Paul the Sunman]

Regarding limiteds, it never occurred to me (I can be a bit slow) that the DA limiteds are a "set"! You have excellent ultra wide, wide, standard macro, standard and portrait lenses in one neat series!

Very true. Hey Ricoh (or KEH), sell them in sets! Buy six for the price of five. Only choice is silver or black. Make it also a kit option with a new body.
Or create a Pentax Limited membership. With each new limited, your benefits increase on future purchases.

Sort of unlimited Limiteds?