[toukan]

I bought aHD DA15 Ltd here a few months ago and am trying to determine if it is as sharp as it should be (or as sharp as other reviewers rated it). While the images look pretty good, I am not convinced that it as sharp as the reviews i read. Anyone have any suggestions as to how I can measure or have someone test it? Of course, i could also just post some pics and let the wise counsel on this site give me their feedback. In order to properly evaluate the lens, is there a particular aperture/shutter speed combination that would be more suitable for evaluating the lens? Also, at what distance from the subject does sharpness start to drop off or within which distance is the subject sharpest? Any advise or input would be most welcome. Thank you.

[Donatas22]

Have you tried FF/BF check? Are the pictures focused on LV mode also unsharp? I have got the same issue and it seems that the problem is not in sharpness of lenses, but problem with focus, especially when focusing to the infinity. I'm still on the researching of the focus.

[pixie]

I have the DA version of the 15mm. The optics are reported as being the same in the DA and HD versions. I have found it to be a very sharp lens. In general, the closer to the subject, the more precise you'll have to be with the focusing. I usually use it for landscapes at F8-F13 on a tripod and it delivers very well.

[mtux]

I've got better results from my DA15 when focused it manually using hyperfocal distance. (i think that because of it's slowness(f/4), the AF can't focus properly on distance objects.)
Also note that white DA15 reported to be super sharp in center, it's not as sharp in corners. and it's better around f/8. not wide open.

---------- Post added 10-15-14 at 03:05 PM ----------

And as always posting some sample photos would help people understand your point and problem faster.

[Adam]

First of all, check to see if all 4 corners are equally sharp. If not, you might have de-centering.

Apart from that, since the 15mm is a low-magnification lens, just keep in mind that you won't get that much detail in the distance, since objects will be rather small to begin with.

[timo]

I often find wide-angle lenses rather unreliable in focusing - my DA15 is unpredictable in sharpness terms, and I suspect focusing must be the reason (despite the huge depth of focus field you should get with that lens).

[bassek]

Try center point AF instead of multipoint with such a wide lens.

Seb

[Kozlok]

I felt the same after first getting the 15. It took me a while to "get" the 15. Try getting really close to your subjects. It really shines at f8. One more suggestion, join the "single in..." challenge and post a picture with it every day for a month. The crowd in that challenge are very familiar with the 15, and will help you learn how to get the most out of this unique lens.

[noelpolar]

I'm in a similar position with my HD DA 15. I recently took a 100 or so images with it whilst on holiday OS, in a mindful way of the lenses requirements, and my jury is still out. No such isses with my HD DA21 or FA limiteds. Any way, even with things in mind such as it's field cuvature, need to get stuff/something close in the frame, bringing the focus back from infinity etc, it still hasn't done much for me. I'll probally do a monthly challenge with it as suggested.....but a month of using it really doesn't excite me......maybe I just don't like wide lenses for landscape type images (is that a mountain in the background?), or the distortion at the edges of the image etc.

I"ll post some typical images tomorrow.

[kh1234567890]

Any advise or input would be most welcome.

I've had the SMC version for about a month or so. Admittedly I'm not all that interested in landscapes but I have had and used superwides and fisheyes (DA10-17, Samyang 8mm etc.) for a while.

My main quibbles with the DA15 are :

• It is quite sharp at the centre even wide open, but soft in the corners until you stop it down to f11-16.
• There is a fair bit of CA - apparent sharpness improves a bit when you correct this.
• The rectilinear projection stretches the image corners considerably, which does not help.
• The stupid lens cap can put a lot of stress on the lens barrel when you store the lens on a camera in a bag which can lead to decentering.
• AF (I always use centre focus and recompose) is unreliable on my K-5ii - the camera AF tends to stop short of the best focus distance, unless you always start from the infinity end stop.
• Because of the wide angle of view the foreground in your shot can be nearer to you than you think and even at the considerable depth of field at this focal length can end up out of focus.
• The field curvature is not a bad as some make out.
• Many of the example shots people post are either downscaled or cropped to disguise the corner softness.
• People who have their mind controlled by this lens should seek professional help

This is about the best that I could do by stopping down to f16 and defocusing slightly :




And at f4 :

[Digitalis]

t is quite sharp at the centre even wide open, but soft in the corners until you stop it down to f11-16.

that was my biggest gripe with the DA15mm f/4 Limited, it is a lovely small lens but it simply didn't deliver in the corners. So I bought a Sigma 8-16mm f/4.5-5.6 and although I went through a few copies of that lens to find one that wasn't de-centered, I was sent one by sigma that visibly outperforms the DA15 across the frame when stopped down to f/8~f/11

[johnyates]

I found the DA 15mm was quite sharp in the center, but not so much on the edges, due to field curvature. I sent it in to Pentax Canada who tested it and informed me that it was performing 'within specifications'. I sold it and replaced it with the DA 12-24 which I think is a much better lens for corner to corner sharpness.

[kh1234567890]

I found the DA 15mm was quite sharp in the center, but not so much on the edges, due to field curvature.

It always gets blamed on field curvature - if it were then you could negate this by focusing on the corners. In my experience you can't, it is just soft outside the centre at the wide apertures. The DA15 is by far the worst of the limiteds.

[Paul the Sunman]

The DA 15 is just about my favourite and most used lens. It is nicely sharp at the centre, but definitely a little soft at the edges. The contrast and colour vibrancy are excellent (particularly if you have clear blue skies), which makes it appear sharper than it actually is if you pixel peep. The soft edges are completely irrelevant for a centred near subject and OOF background, which is where 15mm excels. If you want sharpness across the frame, it is improved if you stop down somewhat.

[asp1880]

it is just soft outside the centre at the wide apertures. The DA15 is by far the worst of the limiteds.

And yet, despite the soft corners, the DA15 manages to lead the "greatest Pentax lens ever" tournament, relegating the FA31 to second place.


It's my favourite lens too, because of the colours, contrast, compactness and build quality.


Regards,
--Anders.