Pentax DA15 Lens — Brilliant!

[jtk]

<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>

 

[jtk]

<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>

 

[mountainvisions]

<p>F/4 is moderately fast to me. Considering it's 1-2 stops faster than I generally shoot. I always point out the size of the Sigma 20mm 1.8 FF lens as a comparison for those who whine and cry that f/4 is slow. Yes, it's slow, but it's also compact and personally I'm more apt to battle a slow lens than a big one.</p>

<p>I don't really believe UWs were meant to be used at very wide apertures. I rarely used my 20mm 1.8 below F/4, and when it was tripod mounted below f/8. Bokeh isn't a strong point of UWs.<br>

<br /> As far as the MZ-S, I agree, but then again the Program Plus, and the MX weigh less than an ist D. Even a metal brick like the K1000 weights less than a K10D. You forget that there is a lot more in the cameras, plus the batteries weigh more.<br>

Last thing, yep, UWs are smaller on a film camera, but mid range and teles are generally smaller on a 1.5X sensor. For instance the 50-135 is significantly smaller than an equivalent 70-200.</p>

<p>It's all give and take. Everyone has an ideal in mind, but the fact is that what is a bonus for one person might not be for the other.</p>

[stephen_van_egmond1]

<p>At 15mm you need a pretty contrived scene to get any bokeh at all. The difference f2.8 to f4 is trivial. The other rationale would be fast shutter in low light -- but for me anyway, a wide-angle lens only gets play outdoors during the day or sunset, when I'm in the f4-f8 range anyway.</p>

<p>Frankly, I would trade my 14mm 2.8 for a 15mm f4 in a heartbeat. If anyone who lives in Toronto wants to trade, drop me a line :)</p>

<p> </p>

[michael_kuhne]

<p>The design of the 15mm f/4 LTD is for compact carrying and low distortion. To achieve this, speed is sacrificed. It is always the same- a fast lens means more weight and size. The 43mm LTD and the 77mm LTD are fast prime lenses, and remarkable design achievements for size and quality.</p>

<p>I take a lot of stock in truly scientifically set up tests, that are thorough in testing both near and far focus, and also use actual comparative images that I can see for myself. I am more impressed than peoples' opinions which are made under varying conditions, and are radically contradictory from one person to another.</p>

<p>I am sympathetic to smaller compact portability. But I understand also why some would put up with added size to gain speed. Regardless if one shoots no wider than f/4, with a fast lens that is not near wide open, and lens performance is hitting its better range by f/4. In addition, the fast lens affords brighter viewing- particularly importent in low light use.</p>

<p>Full -frame extra wide fast primes are rather uncommon, but not that hard to find. Nikon makes one and Canon makes a couple. It is too bad Pentax dropped the 24mm f/2, but from what I've seen the Sigma 24mm f/1.8 is even better and far less costly. The difference is, from 35mm film bodies where the 24mm field of view IS available in a fast, bright-viewing, low-distortion prime, there is NO such animal for a DSLR, other than having an expensive FF body. Not available AT ALL!!! </p>

<p>People have repeatedly written in as to being able to see noise in a blue sky at 400 ISO with their K10D. Not a big deal, since if examined closely, a very good low-grain film can exhibit similar results. Print film has been tested as lower grain at ISO 400 and above than slide film. Kodak 400 UC and Fuji Superia Xtra 400 and even 800 are very low grain. So both film and DSLRs can exhibit grain/noise. I have many shots that are very practical and usable from these films.</p>

<p>Here's one from my Sigma f/1.8 hand held on my K100D, wide open and 1/15 sec and ISO 800. </p>

<p> </p><div></div>

[michael_kuhne]

<p>Here is another wide open and 1/20 sec. at ISO 1600 using the K100. I am now about to evaluate the performance of the K20D and NR on "Weak". Results should be pretty sharp, even with this mild NR. We'll see how goes the noise at such ISO. Should be interesting to compare with low light from the K100.</p>

<p>I would NOT have gotten these shots with an f/4 lens, even if I could see well enough through the VF.</p>

<p>On a film body, I would have needed a tripod- no SR. But the view would have been much wider.</p><div></div>

[jtk]

<p>Night shots using a very slightly wide(24=36mm) lens on APS don't seem related to discussion of an infinitely smaller, more seriously wide 15/4 (15=22mm). </p>

<p>Some of us do think of DSLRs as tools for photographing static objects (those gorgeous bridge photos) or other subjects where grossly large and heavy lenses are no handicap (most here seem devoted to zooms rather than primes). An f1.8 lens might be important if one was using a camera with a relatively inefficient finder, but would be less so with a prism, especially at infinity or with good autofocus. I find my slowest lens (3.2) easy to use with K20D at night.</p>

<p>Some of us often photograph people up-close and personal... monster lenses may be intimidating to our subjects... the tiny 15/4 might be perfect sometimes (15=22 and 21mm has been used forever by Leica shooters for street and various non-extreme illustrations).</p>

<p>When restricted to film (eg 800iso Fuji NPZ rated 1600) I sometimes found full aperture f1.4-f2 important. But with K20D's brilliant prism, superb IS (good for at least three stops) , noise lower than grain @1600iso (or even 3200), I'm as comfortable using a slower shutter speed and f/2.8 or smaller. And that'd be even more true with a 22mm equivalent lens than with a 36mm equivalent lens.</p>

<p>YMMV</p>

[mountainvisions]

<p>I usually don't shoot daylight shots at ISO 400 on the K10D or the K20D or the ist D. But I never EVER shot an ISO 400 daylight film for anything that was more than a snapshot, or small print.</p>

<p>ISO 400 film stunk, i'd rather have ISO 400 digital. Quite honestly, you could see grain/noise in a 50 speed film at high enough scan resolution. Often this was pepper granules, but it could also be grain structure. I've noted often people have become a bit jaded by digital and it's higher ISO capabilties, all one needs to do is load an 800 speed (color) film and have a shootout with the K10D to see how much better digital is at higher ISO.</p>

<p>As far as noise on a blue sky. Take Nik Dfine, use color dropper on the blue, then select the other key areas that lack perceptible noise and set the NR to 0%, and reduce the blue sky till it looks natural. No more noise, yet much more detail in the rest of the scene than a 400 speed film.</p>

<p>It's all give and take, but there is no way I'd take a 400 speed film over a digital SLR sensor set to 400. The only exception I can think of MIGHT be Provia 400X.</p>

<p> </p>

[mountainvisions]

<p>BTW, on this image shot at 100 speed fuji c-41 I couldn't stand the grain in the sky at a 10MP scan. So I was forced to denoise it. Again this was 100 speed film with a perfect exposure out of the camera.</p>

<p>So while the K10D might have noise in the sky at 400 iso, print film had grain in the sky at as low as 100 ISO. I'll take the extra 2 stops!!!</p>

<p><a title="New Years Winter Wonderland In The High Peaks" href=" title="New Years Winter Wonderland In The High Peaks"> <img src="http://static.flickr.com/126/380120506_298b6a54b3_d.jpg" border="0" alt="" /> </a> <a title="New Years Winter Wonderland In The High Peaks" href=" title="New Years Winter Wonderland In The High Peaks"> </a></p>

<p> </p>

[michael_kuhne]

<p>It is relevant because APS cannot get both fast and wide. So the 15mm LTD has to face a design limitation, hence the fact it has to be f/4.</p>

<p>Not to put it down at all, just being realistic, that this is not, and cannot be, a fast lens, with the benefits that come along with fast lenses. So Pentax did the logical thing, and designed for compactness and low distortion. Even to get to f/2.8, the size of the DA 14mm f/2.8 is a good example. And this f/2.8 is a truly "moderately fast" WA prime lens, providing like a 21mm FOV on FF. If needing that extra stop of speed, forfeit of the compact size of the new 15mm LTD would be the price. Other brands do not have this choice. </p>

<p>With having both wider angle and smaller, darker aperture, it is harder to see your framing in very dim conditions, because f/4 in the VF is not as bright, and at a very wide FL objects appear smaller. I know this difference, because I sometimes do use my DA 12-24mm f/4 under such conditions. But for the above use, I had to switch to my less-wide, but truly fast Sigma 24mm, like having a 35mm WA lens on FF, in order to be more functional and to get the shutter speed I needed. It is still WA, and very useful on an APS body. This does not mean I regret having the DA 12-24mm f/4 lens at all- it is indeed a fine lens. Apparently, the amazingly compact 15mm LTD is as well. It just cannot be seen as fast, not could it have been so. For a zoom lens, f/4 is "moderately fast" because f/2.8 is as fast as it gets. There have been expressions of disappointment regarding the 15mm LTD's f/4 aperture, but upon examination, this design limitation is understandable.</p>

<p>Justin hit the nail on the head when he said there are trade-offs. While there are disadvantages with WA, as he stated, APS advantages in the telephoto area are undeniable. The DA* 200mm f/2.8 is an example. Its equal on FF would be a very costly 5-6 lb. blunderbuss, where instead this lens weighs in a bit over 1-1/2 lb. and is about half the length, having a reasonable 77mm filter size. I can carry it in a large coat pocket without its hood. I stick the hood iinside my jacket, at the risk of looking transgendered. So yes, I will gladly accept the necessary compromises APS imposes at the wide end to get the advantages at longer FL. When I really need to avoid those compromises, I still have and use my film cameras! </p>

[michael_kuhne]

<p>I recently saw a quite large-size print, I am thinking 16x24, taken under low-light conditions, made by a man who works behind the photo counter at a large chain store where I shop. He shot it with a Pentax K1000, and using Kodak UC 400. It looked amazingly smooth and detailed. Very impressive. I am not sure of the FL used, but it appeared to be a WA shot. The idea that film is so bad it is noisy at anything beyond ISO 50, and with an APS DSLR it is so much less noisy that we no longer need fast primes, is nonsense. <br />And BTW, unlike digital, film's "noise" does not change that much as you change to a larger format. Yes, you stretch the grain more with enlargement, but basically still the same with MF as with 35mm.</p>

[14mm 2.8l]

<p>15mm aps-c is not 22mm.</p>

<p>According to pentax its "23mm":</p>

<p><a href="http://www.pentaximaging.com/camera-lenses/smc_PENTAX_DA_15mm_F4_ED_AL_Limited/">http://www.pentaximaging.com/camera-lenses/smc_PENTAX_DA_15mm_F4_ED_AL_Limited/</a></p>

<p>$649 USA</p>

<p><a href="http://www.pentaxwebstore.com/detail/PTX+21800">http://www.pentaxwebstore.com/detail/PTX+21800</a></p>

<p>I see this 15mm LTD as closer to a 24mm f4 lens than I see it as closer to a 21mm f4. Every mm focal length on wide side does make a difference. I've owned several 24mm film lenses. None were ever as slow as f4. Instead they were f1.4, f2.0 and f2.8. Personally, I found the f2.0 was the best for me.</p>

[joe_jackson4]

<p>Hmm, this lens is clearly a compact, low-distortion, 800€, "rather soft", f/4 paragon... :) Only a fridge-magnet-fondling fool would disagree...</p>

<p>But OK, deep down we all know that the main thing is that it says "Limited" on the side and it's made of metal... :)</p>

[jgredline]

<p>Does this lens have the DOF markings on it? If so, is it optimized for the 1.5 crop factor?</p>

[miserere_mei]

<blockquote>

<p>15mm aps-c is not 22mm.<br>

According to pentax its "23mm"</p>

</blockquote>

<p>Pentax's have a 1.53x crop factor, so 15mm is 22.95mm-equiv.</p>

[andrewg_ny]

<p>Javier, yes there is a DoF scale. Whether they've calibrated the DoF markings for DA lenses differently for the smaller sensor compared to how they determine the markings for FA lenses is a good question.</p>

[14mm 2.8l]

<p>I'm curious Mathlete Miserere, with a K20D viewfinder:</p>

<p>

<table id="productview_tblSpecs" border="0" cellspacing="0" cellpadding="0">

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<td> </td>

<td>

<p>"Viewfinder Type - Pentaprism; Coverage (field of view) - 95%; Magnification - 0.95x (w/ 50mm f/1.4 at infinity)"</p>

<p>& this 15mm LTD lens mounted what is the view you see? Not 23mm, is it 25mm? I realize the sensor records the outter edges you do not see since K20D does not have a 100% viewfinder.</p>

</td>

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</tbody>

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</p>

<p>Spec pulled from here:</p>

<p><a href="http://www.pentaximaging.com/slr/K20D/">http://www.pentaximaging.com/slr/K20D/</a></p>

<p><a href="http://www.pentaxwebstore.com/product_detail.asp?T1=PTX+19381">http://www.pentaxwebstore.com/product_detail.asp?T1=PTX+19381</a></p>

[michael_kuhne]

<p>The fact remains, to get those shots I needed my f/1.8 Sigma WA. </p>

<p>There is film and there is film. They differ considerably from one to the other in grain characteristics. When a new one comes out having less grain, you don't have to sell your camera and buy another to get that benefit.</p>

<p>Then, with a DSLR, all have some degree of in-camera electronic image processing, including NR. If not over-agressive, this will not noticeably reduce sharpness, but will reduce noise. So the end result depends on the sensor, and also the electronic processing of that sensor's output. And that is done WITHOUT additonal optional NR being switched on! Film does not have this in-camera manipulation.</p>

<p>With more mp, a DSLR is noisier and requires more in-camera NR. From what I have seen, images from a 10mp APS DSLR are not much, if any less noisy at ISO 200-800 than the lower-grain films are WITHOUT ANY NR compensation. With a film camera, If one selects a less than optimum film for grain, that is a different matter.</p>

<p>From what I have seen, up through ISO 800, there is not much to distinquish the lower grain films from an APS DSLR of say 10mp or greater, that has not had overly aggressive NR processing. The Pentax K series thus far has not tended to do that. The K200D, from all reports did improve its noise processing perormance without over-doing it and losing sharpness, compared to the K10D, which uses the same sensor. The K200D got good ratings for noise. </p>

<p>I cannot put more than one image together in the same post- but here are 2 images I scanned and downsized from a high-speed film I like, Fuji superia Xtra 800. It is low-grain for this speed, and has extra layers for mixed lighting. The 400 is even a little better for grain, and the Kodak UC 400 *might* be better yet. The first one, I had not planned for this type of WA shot. I was there to shoot action. So I just had my Pentax 28-105mm f/3.2-4.5 zoom. Unfortunately, as I was framing the shot, some guys came quickly down the isle as I pulled the trigger, and the AF was drawn towards them. I did not realize this at the time, but it was still usable to commemorate that event.</p>

<p>Then I will post one example I took with the K200D at ISO 1600- no added NR used. To my eyes, the K200D at ISO 1600, while acceptably good, does not look cleaner than that film at ISO 800. </p><div></div>

[michael_kuhne]

<p>The 2nd-</p><div></div>

[michael_kuhne]

<p>And the K200D shot-</p><div></div>

[mountainvisions]

<blockquote>

<p>And BTW, unlike digital, film's "noise" does not change that much as you change to a larger format. Yes, you stretch the grain more with enlargement, but basically still the same with MF as with 35mm.</p>

 

</blockquote>

<p>Unfortunately the very nature of "stretching the grain" is the limitation of film. You are correct though the grain structure of films at various sizes remains essentially or exactly the same. <br /> <br /> Bearing in mind in my example above I'm talking about 100 speed print film (c-41) which I never really used for anything other than snap shots. The main reason I have so much c-41 is because I worked at several labs both commercial, pro and 1 hour where I was able to process my film for near nothing (but legal, and within the confines of policy). So buying film in bulk, and then processing it for less than 20 cents a roll (and I could cross process for the same price) meant film was less expensive than digital for me for several years. C-41 in a small SLR was essentially my digital compact! Slide film on the other hand I needed to have processed or process myself at home, the cost per roll was very similar unless I was able to do about 10-15 rolls using a Chrome Six kit at once at home, or I was push processing which could save at least $15-20 for 15 rolls.</p>

<p>As far as the 400UC I used it a lot actually, it was cheap and decent quality. However, I preferred the harder to get 100UC.</p>

<p>I just scanned some Kodak Gold 1000 which were mostly shots of the 1999 Yankees ticker tape parade, and Caney. The grain was awful to the point of obscuring resolution. No way would I ever go back to film for high ISO shooting vs. any format DSLR. Fuji 1600 was fine when I was shooting for the paper in the late 1990s, but it just can't compare to digital for resolving power or noise.</p>

<p>Michael, what I would recommend is you properly expose a RAW shot on your DSLR at 800 and compare it to a properly exposed 800 speed color film of your choice in a reasonable size print (say 8x12), I bet you prefer the digital image!</p>

[mountainvisions]

<p>Michael,</p>

<p>One final point.</p>

<p>Your hockey shot looks about 1 stop under exposed. I realize with print film you perhaps had a stop of latitude, but digital is more like slide film, and even more so at high ISO. I've always said, with a digital sensor at it's maximum usable ISO (that would be 1600 for the ist D, 2500 for the K20D, and 1600 for the K10D) you need to be on the money when shooting RAW or JPEG. Even in RAW more than a 1/3 of a stop and you are going to have issues.</p>

<p>This is why I said above to take 2 shots with equivalent ISO (film and digital) and make sure you bracket them, then print the best exposure for each. I am definitely willing to be overall the color print film falls short of the digital. In my opinion while shadow noise in digital at high ISO can be nasty, print film tended to get brown and muddy in the shadows. So 6 of one, and a half dozen of the other.</p>

[mountainvisions]

<p>One last post here....what did this thread start on again, and how the hell did we get into a film vs. digital debate.</p>

<p>I'm not even asking this as a joke, I really am confused how we got to this point. I keep looking at the thread title and scratching my head. I know somewhere it turned into how such and such lens wouldn't be necessary on a film camera or maybe the opposite, but where did the film vs. digital issue come into play?</p>

[jtk]

<p>Justin, it got off topic because somebody wanted to talk about a totally unrelated lens, as well as his noise theories :-) </p>

<p>Then the anal-ists got into the act, anxious about fractional millimeters . Well, hell, somebody's got to do it :-)</p>

<p>In any case, the reason FOR the 15/4 is physical size. Many, used to Voigtlander's similar Leica wides, will be happy with f4, which seemingly will illuminate the frame far more evenly than Voigtlander does but may be less screamingly sharp.</p>

<p>There's no alternative to that 15/4 unless somebody's willing to haul an absurdity, zoom or prime, in exchange for f2.8. </p>

[michael_kuhne]

<p>Justin, any more exposure than this and I would start to blow out highlights excessively! Maybe RAW would have preserved the highlights a little better. It "looks" under-exposed, but what you see here is about the way the lighting was. I have noticed, however, that the K200D, and possibly the K20D as well, tends to slightly under-expose, especially in lower lighting. I think it's a metering issue as it relates to ISO sensitivity. Lately, camera tests have not included ISO accuracy. I agree regarding the exposure latitude being closer to slide film. Latitude is one other reason I often turn to print film for certain uses.</p>

<p>I have done the RAW thing, then just used the Pentax AUTO process, no tweeks, and could see no substantial difference, for the most part. Sometimes very strong highlights are better preserved in very high-contrast situations, and shadow detail can be a little better in some shots.</p>

<p>I do think film formulas never were successful above ISO 800. When going above ISO 800, a digital APS DSLR is definitely cleaner. To me, what I get with that particular ISO 800 film, as above, is very acceptable for that ISO.</p>

<p>One way or another, a DSLR image is as much a product of electronic processing as anything else. Generally, even with digital, one tries to keep within ISO 800 when possible.</p>

<p>I have had difficulty getting digital prints to look as good as those I get back from an ordinary local film service, though I have a very good quality photo printer. There is no denying, for very WA shots requiring a fast lens, one must turn to FF, whether film or digital.</p>

<p>I think dpreview did try to be fair in its test of the 15mm LTD. When they spotted a shortcoming, they called a spade a spade. At the same time, they acknowledged that it is unrealistic to expect a faster lens in such a design, and that it offers virtues not to be found elsewhere.</p>

<p>The reason the thread went here is over this lens not being fast, because that cannot be so. To get truly fast and very wide, one has to go to FF, film or digital.</p>