Pentax DA15 Lens — Brilliant!

<p >Last week I bought the Pentax DA15 lens that I have been (not always patiently) waiting for since it first appeared on the roadmap.</p>

<p >I follow the Carl Weese philosophy in testing: put the lens on the camera and go shoot the sort of pictures you normally take, then see how you like those.<br>

I like what I'm seeing. <br /></p>

<p >One striking feature is the near absence of linear distortion. I also enjoy the smooth, 'natural' rendering of detail (opposite of the Flickr school of digital exaggeration).</p>

<p >Also important is the compact size, since I always have my camera with me. [Found a rubber Nikon 54mm lens cap that just fits tightly over the collapsed lens shade—not perfect but good enough for now.]</p>

<p >Posts for the last four days on my More Original Refrigerator Art blog (link below) were all made with the DA15.<br>

May not be your 'cup of tea', but it sure is mine, and worth every penny. <br /> <br /> Cheers, <br /> <br /> Tyler Monson <br /> <a title="Click to open link in a new browser window" href="http://www.ora2.blogspot.com/" target="_blank" title="Click to open link in a new browser window" >http://www.ora2.blogspot.com</a></p>

<p>wow that distortion is just about non-existent in some of your building shots and walls... those straight lines are straight! very interesting...</p>

<p>I must say that I am impressed. exactly what I wanted to see. I also agree that when testing stuff, use it as you normally do. It is the best way IMO to judge for one self.</p>

<p>Almost no perceptible distortion...now you got me thinking if to get the Voigtlander 20mm or the DA15...now i'm wondering the price difference between the both...</p>

<p>Tyler..excellent!...are most of those images uncropped? </p>

<p>Your images look more rectilinear than those from my 21/3.2 (the only weakness in that Pentax).</p>

<p>The most important comparison for me would be with that Pentax 21 (poor man's Summicron or Elmarit), or the 21/4 CV on 35mm (poor man's Super Angulon). The zooms underperform in too many ways, bulk in particular, to be relevant. Looks like your 15 illuminates very evenly, unlike the 21 CV (which is however screaming-sharp).</p>

<p>Good stuff, Tyler! I especially like <a href="http://4.bp.blogspot.com/_gDyciaOyYSo/SfhB4H3pwaI/AAAAAAAAEsk/MboGmIh8mlI/s1600-h/Please_Use_Other.jpg">this one</a> and <a href="http://3.bp.blogspot.com/_gDyciaOyYSo/Sfb2kIbSWsI/AAAAAAAAEsM/uZ-0Xk7A53c/s1600-h/Winter_Tree_in_Alley-b.jpg">this one</a> .</p>

<p>The most important lesson you're teaching us is that a lens is only good if the photographer using it likes it. I don't particularly care what DPR has to say about it.</p>

<p>Nice to see some positive info on this lens. I subscribe to that lens testing philosophy myself.</p>

<p>I had a pretty good feeling in an age of computer assisted lens design, that no prime could be as awful as people were trying to imply it was.<br>

<br /> <br /> Thus far I see the strengths of this lens are moderately fast, superbly small, lacks distortion, lacks vignetting.</p>

<p>I think this paired with the 21, 43, 90, and 200mm f/4 will be a great travel setup for me! Compact, light and high quality.</p>

<p>Justin ... that's two lenses too many for a "travel kit". Stick to three lenses: you'll be better off. <br>

Mine: UW zoom, fast normal, fast portrait tele. That's it.</p>

<p>

 

<p>12-24, 35 Limited & 77 Limited?</p>

 

</p>

<p>Godfrey,</p>

<p>I agree, it all depends on what I have in mind. My typical kit is 21, 28/35T&S/43 (pick one), 90. If I know I'll be using a tele, I'll take a longer lens like the 70-300 or 200mm f/4 but I usually don't bother with anything longer than 90mm. The 645 200mm f/4 is bit smaller and lighter than the 70-300, and a bit faster at 200mm.</p>

<p>However, one of the nice things about Pentax is my kit is smaller than many 1-2 lens zoom kits.</p>

<p>My 21, 43, 90mm kit is about the size of a FF 28-70 2.8 zoom and weighs less. Had I went with the 70mm it would be even smaller and lighter.</p>

<p>Since my travel bag consist of a LowePro TLZ and 1-2 attached lens cases I can only carry so much. Since my flash usually takes up one of those cases, I'm even further constrained. Thanfully Pentax has put a lot of thought into compact lenses, and Cosina Voightlander has filled in the gaps!</p>

<p> </p>

<p>Thinking about it some more ... Pentax' 12-24 is a bit bulkier than I like to travel with. </p>

<p>Next to last travel with the Pentax kit I carried 21, 35 and 77mm. Last travel with it I had the 21, 43, and 70mm lenses. In both cases I didn't really miss not having the 14mm with me, but I'd have had two/three more options. The 14 was just a bit too big, the 12-24 is bigger, and the 15 is small. So a four lens kit ... 15, 21, 43 and 70/77 ... would do me fine. I use anything more tele than that pretty infrequently. </p>

<p>It just seems a bit too many choices for travel. I find it better to reduce choices of equipment so as to concentrate more on seeing. :-)</p>

<p>I agree. Sometimes it's better to have fewer options, so you work with whatever is on the camera rather than always think about switching. Having a lot of options means over thinking and spending a lot of time changing glass. I like a 3 lens kit myself, 4 tops, but when I take 4 usually one of them doesn't see much action.</p>

<p>The 12-24, 14, and Sigma 10-20 (two I considered, one I settled on) are too big for travel unless you know you need a UW, or UW is your forte and preference. For me it's not, and I think the 15mm would be ideal in the true wide angle role. Plus it's small enough to take it even if you may not definitely need it.</p>

<p>I really think this lens (the 15 Limited) is going to develop a following down the road after all the backlash dies down.</p>

<p><i>"backlash" ::</i></p>

<p>There's always so much debate and silliness on equipment forums.<br>

Too many people taking things like DPReview and other pundit opinions too seriously. I'm sure it's a fine lens. :-)</p>

<p>Hi Tyler<br>

I have a question for you: what's your impression so far of the AF function with the 15mm? Accurate? Consistent? Any quirks?</p>

<p>Ah, for the full-frame film days, where you can take a lightweight compact body, a modest-size UW zoom, like the Pentax 20-35mm f/4, or Tokina for that matter, plus the 43mm and 77mm Limiteds! My MZ-S weighs considerably less than even my K200D, and my ZX-L weighs less yet.</p>

<p>I would not call any f/4 prime, other than a telephoto, "moderately fast". In fact, on the slow side for a prime lens. f/2.8 is average or "moderately fast" for a WA prime. But f/4 is adequate, and obviously a trade for the small size. Speed is not one of the good points here, but small size and low distortion are the emphasis.</p>

<p>A high-quality option for this new lens in a travel-about or hiking kit will be- the forthcoming compact K7D body, 15mm, 21mm, and 43mm Limiteds, these being small enough so in a separate belt hoster, the DA 55-300mm or even the DA* 50-135mm, is no problem! Going all primes, it would be a LTD set of either the 15mm or 21mm, 43mm, and 77mm. The DA* 200mm can fit into a belt holster as well. That has been my potential thought. Then also possibly taking the 1.4x TC. Each of those LTDs is pocketable, or can fit into a carrying pouch along with the camera with one on it.</p>

<p>Carl Weese: I have made about 200 exposures with the DA15 on a K20 (on AF, at all distances) without a single "damn, it's out-of-focus" experience. However, I shoot almost everything at f/8 so there's bound to be a lot of latitude.<br>

I am going to try the DA15 on my K10 for a while now, and that camera, with the DA21, did have its moments of confusion.<br>

Anyone know why the EXIF info only reports "distant view", "close view", and "macro"? Reminds me of the old box camera that had three distance settings. Surely there must be a way in which the lens, once focused (via contrast detection or whatever) could relay more accurate numbers to the software.<br>

Flashback! I remember building a VisiCalc spreadsheet in 1979 to calculate depth-of-field tables for my 4x5 lenses. Ah, the (then) sacred circle of confusion!<br>

------------------<br>

John Kelly: The only cropping is occasional trimming of the sides, because I am less fond of the 3:2 proportion. The rest of the pictures in that blog (with noted exceptions) were all taken with the DA21 lens, and there I've calculated a stock correction for distortion that I apply in Photoshop.<br>

Cheers,<br>

Tyler</p>

<p>Michael, </p>

<p>In 35mm film days, there were relatively few fast ultrawides either. The FA*24/2 AL was a notable exception, the A28/2 is almost mythical in how hard it is to find. And with 35mm film, by the time you got to ASA 400, grain cuts down on practical usability far more than an f/4 lens. Etc etc. </p>

<p>Just kvetching.. ;-) The FA20-35/4 AL was a wonderful lens, even on the *ist DS, with performance to rival many primes and it was light (if not compact). I only stopped using it once I had the DA21, which was a better performer, and then the two lenses I got the most use out of were the DA21 and FA43. The FA43 is one of the most special Pentax lenses of all, imo. </p>

<p>My three 'nevers'....</p>

<p>1. NEVER trust anything ANY lens tester/reviewer says.</p>

<p>2. NEVER buy any camera without handling it first.</p>

<p>3. NEVER say never.</p>

<p>cheers Steve.M.</p>

<p>"I've calculated a stock correction for distortion that I apply in Photoshop.<br />Cheers,<br />Tyler"</p>

<p><strong>Tyler: Yikes !.. should we reconsider what you said about distortion and 15/4?</strong> </p>

<p> Have you Photoshopped 15/4 distortion the way you evidently did the 21/3.2 ? Or is the non-fixed 15/4 more rectilinear than the non-fixed 21/3.2 ?</p>

<p>That sounds good, Tyler. I've found the 21mm and the 12-24 to have significant AF issues with both K10 and K20, while the cameras' AF functions very well and very consistently with 31, 35, 40, and 70. A low-distortion 15 with reliable AF sounds better and better.</p>

<p>John Kelly: In your quote of what I said, step back one more word: "there" meant I was talking about the DA21. The correction that I use with my DA21 is simply +3 on the distortion slider in the lens correction filter. Not a big deal in my book.<br>

My tests with the DA15 led me to conclude that no correction for linear distortion was required, so I have applied none.<br>

To my thinking, the computer's "virtual darkroom" is a natural and essential part of digital photography, just as the darkroom was in silver-based photography.</p>

<p>Wow...Godfrey and Carl have shown up on the same thread...</p>

<p>:-o</p>

<p>Maybe this is a sign that I need to buy the DA 15 Ltd...</p>

<p>Carl, I haven't particularly noticed that (yet) with DA21 but with DA12-24 I have often noticed especially in somewhat lower light that I may get AF confirm at a distance that is obviously a foot or more different than reality.</p>

 

<blockquote>

<p>Anyone know why the EXIF info only reports "distant view", "close view", and "macro"?</p>

</blockquote>

<p>I don't <em>know</em> but I have a theory and this reminds me of some discussions a while back (with Justin?) about the capability of K-mount lenses reporting focus distance to the body and how the body might use it. I think we were probably dreaming about some automatic hyperfocal mode. </p>

<p>Good times. </p>

<p>Anyway, your mention of what EXIF is reporting may be somewhat telling--the lens may only report focus distance back to the camera in a very coarse manner, which doesn't surprise me all that much. I will guess that Pentax cameras have historically used this basic distance information to select scene modes--remember all those AF models with "Auto Pict" and the like? It probably combines this information with the focal length (also reported to the body in somewhat course 'steps') to pick which mode to use--like picking whether to prefer 'macro' vs. 'portrait' vs. Landscape. I wonder whether this data gets used for anything else like flash exposure?</p>

<p>A little more digging on <a href="http://www.bdimitrov.de/kmp/technology/K-mount/Kaf.html">Boz's tech page</a> , original source unknown to me:</p>

<blockquote>

<p><strong>Lens-to-subject distance</strong> . This is used by the more advanced bodies for calculating if the flash is powerful enough to illuminate the subject that is in focus. In addition, this is one of the parameters taken into account when the body is in one of the "smart" picture modes and has to choose a program curve.</p>

</blockquote>

<p>Furthermore...</p>

<blockquote>

<p>The lenses contain a ROM chip that holds the program curve (brightness/shutter speed/aperture) for prime lenses or up to three program curves for zooms at their different focal length settings. The distance information is hardwired on the lens barrel. A number of tiny parallel conducting/non-conducting strips are glued to the rotating part of the lens. The same number of contacts are attached to the fixed part of the lens. As the lens barrel turns during focusing, different combinations of the strips are detected by the contacts. There are four parallel strips in the F 50/1.7, resulting in at most 16 different distance settings. But for that particular lens not all combinations are used.</p>

 

</blockquote>

<p>So perhaps "precise" focus distance isn't in the mount design or at least probably not implemented in actual lenses?</p>

<p> </p>

<blockquote>

<p>Wow...Godfrey and Carl have shown up on the same thread...</p>

</blockquote>

<p>As far as I can tell, Carl registered with P-net <em>just </em> so he could participate in this thread. Now <em>that's</em> interest!</p>

<p>"To my thinking, the <a href="#" target="_blank">computer's</a> "virtual darkroom" is a natural and essential part of digital photography, just as the darkroom was in silver-based photography." - Tyler Monson</p>

<p>Yes. I agree 100%....though I do love lenses that don't distort ...not asking a lot of the 30mm equivalent 21/3.2, but it does distort...which means certain images have to be cropped along the long dimension if I want a squared-away image...can't be avoided unless I allow a lot of room around the rectangle, which means the lens becomes effectively less wide on the short dimension (like your crops)...</p>

<p>My awkwardly-worded question arose because you fixed 21/3.2 distortion. ...I hoped you'd confirm that you DID NOT do that with the 15/4. Thanks for clarifying.</p>

<p>My only disappointment with the 21/3.2 is distortion, so I naturally wonder about distortion and the 15.</p>