Pentax's 70mm moderate telephoto is an enthusiast's dream.

When I was a kid my father had (and in fact still has) an Olympus OM-2n SLR, with a handful of lenses of various focal lengths. With their metal construction, smoothly dampened focus rings, and in some cases slide-away hoods, these lenses always struck me as being extremely well engineered. And in fact, they were.

Somewhere along the way we consumers have forgotten what a pleasure it is to use such well-designed and engineered lenses. Nowadays some of the nicest lenses feature plastic barrels, slightly sloppy tolerances, and excessively bulky design. While optics may have improved over the years, in general it seems design quality has taken a step back from those days when lenses were assembled by hand.

But one day a few years back, Pentax departed from this trend. While they maintained modern (plastic) production of many of their existing lenses, they added a new tier of lenses, above their consumer-oriented tier. This new tier consisted of superbly engineered, highly refined, hand assembled, metal barrel lenses. These lenses are known as "Limited", in the Pentax lineup. The first ones introduced were for "full frame" (35mm film) SLR's: FA31, FA43, and FA77. Over time, the FA31 came to be known as perhaps the best SLR lens ever made by Pentax. The 43 and 77 became legends too. These full frame lenses are still in production today.

While these "FA" lenses still work fine on Pentax's current line of digital SLR's, Pentax has also set out to design a series of "Limited" lenses specifically tailored to their digital bodies. These lenses are the SMC Pentax-DA 21mm f/3.2, SMC Pentax-DA 40mm f/2.8, and the SMC Pentax-DA 70mm f/2.4. These new lenses are optimized for APS-C sized digital sensors, with special coatings that minimize fringing on digital SLR's. But perhaps most notable among the changes exhibited in the DA-Limiteds is their size. Each of them is considered a "Pancake" lens. Each is less than one inch deep when mounted on a camera body.

With their fine engineering, tight tolerances, and compact metal bodies, these lenses simply feel like the lenses we almost forgot about; the high quality metal-barrel lenses of 25 years ago. These are true photographic tools, not mass-manufactured camera accessories.

With that background, I'll discuss the SMC Pentax-DA 70mm f/2.4 Limited.

The SMCP-DA 70mm f/2.4 Limited is an ultra compact metal-barrel moderate telephoto lens designed for digital SLR's such as the Pentax *ist-D, *ist-DS, *ist-DS2, *ist-DL, K110D, K100D, K100D Super, and the highly rated K10D. Its maximum aperture of f/2.4 is fast enough to provide pleasing bokeh for portrait work, and is adequate for low-light use.

The lens comes with a screw-on extendable metal hood, and a snugly fitting metal lens cap, as well as a small leather carrying pouch.

First impressions of the lens reflect the fact that this lens is assembled by hand with attention to quality and detail. The feel and look are great. It's a pleasure to handle. Users will enjoy the smoothly dampened focus ring, the precision hood, and many other "nice touches." I was happy to see a depth of field scale. You almost never see that in modern lenses.

Optically, the lens is designed to accommodate APS-C sized sensors. There appears to be some vignetting (perhaps 2/3rds stop) at wide-open apertures such as f/2.4. It evens out quickly by f/4. Vignetting is apparent at open apertures on just about any lens, and can be easily corrected in post-processing.

Sharpness is really very good wide open at f/2.4 and f/2.8. By the time you get to f/4 its sharpness is amazing across the entire frame. Many lenses get a little soft wide open. While this lens softens a little at the edges wide open, it's still very sharp and exhibits just enough punch. The lens's images are crisp and finely detailed. Distortion (barrel or pincushion) is practically non-existent; certainly low enough to not be relevant under most demanding conditions. One thing that's difficult to quantify is a lens's rendering qualities. This is a ambiguous and vague term describing simply how the images taken with a given lens look. Are they crisp, are they too contrasty, is bokeh smooth or harsh, etc. The DA70 is outstanding in this regard.

The hood screws onto the front of the lens, and extends from 5/8ths of an inch long to nearly an inch long. It seems to be fairly effective at shading the lens, as well as keeping my fingers off the glass. I like the snug-fitting lens cap. It seems to me to be an improvement over fiddling with spring-loaded clips on many of Pentax's other lenses. It should be noted that while the lens is considerably shorter without its hood, its dedicated cap cannot be used if the hood is removed.

When I used to shoot film, one of my favorite lenses was a 100mm lens. I really enjoyed how it felt to use that focal length around town. When I moved into digital, I was sorry to find that due to the DSLR crop factor, the 100mm lens was now a little too tight for such general use as I had become accustomed to. One of the first things I noticed when I started using the DA70 was that I had found an old friend again; the focal length feels (on a digital body) a lot like a 100mm lens would feel on a film body. It's nice to be home. ;)

In my opinion the 70mm focal length (on a digital body) is an ideal portrait length. And this lens is in several ways an ideal portrait lens. Aside from its focal length, it is also relatively fast (f/2.4). Such open apertures are accompanied by the shallow depth of field that can help the subject to really stand out in a shot. Furthermore, the bokeh (rendering of out-of-focus areas) seems smooth and pleasing.

There's one other point that should be made with regards to portrait work that people often fail to consider: In order to take a nice, pleasing portrait, particularly with inexperienced models (such as family members), it's important that the subject NOT be intimidated by the photographer. Pointing an enormous lens at someone will impact how that person responds to the photographer, and that will carry over into the image captured. This lens (the DA70) is not intimidating to most people. It's not going to scare your wife, kids, and pets. It won't upset the locals. It shouldn't attract too much attention, except perhaps for some admiration.

Back to optics... Flare also seems very well controlled. This may be in part due to the built-in hood, but probably has a lot more to do with the lens's optics, which have been designed with coatings that improve their performance with digital sensors.

One nice feature present on all "DA" lenses, including the DA-Limiteds (and thus including the DA70) is "Quick Shift Focus." With this feature, after the camera has auto-focused a scene, the photographer may turn the lens's focus ring without explicitly switching to manual focus, and the lens will immediately shift temporarily to manual focus mode automatically. This allows the photographer to "touch up" the focus without fumbling around with the AF/MF switch. I've grown to enjoy this feature on my DA16-45 and DA50-200. It's surprising how often I use the feature. I'm glad to see it present on the DA-70 too.

No review would be complete without a discussion on the negatives of a product. This lens is such a pleasure to use, it's hard to speak critically of it, but here goes. The lens hood is well designed. But if you wish to use the lens without a hood (especially to benefit from the compact size of the lens), you're going to need to pick up a lens cap that clips into the threads like Pentax's more traditional lenses. The cap that comes with this lens will only fit over the hood. There you have it; the lens pretty much has to be used with its telescoping hood. I would do so anyway, but others may dislike being constrained in this regard.

In conclusion, the SMC Pentax-DA 70mm f/2.4 is small, well built, optically excellent, and fun to use. I wish I had acquired it several thousands of shots ago.