An Optical Paragon
Discussing the Pentax DA 35mm f/2.8 Macro Limited Lens
By varying pathways, my friend Carl Weese and I both found ourselves photographing with new Pentax K20D’s and one particular lens, the then-brand-new SMC Pentax DA 35mm f/2.8 Macro Limited. (Carl is a photographer and writer who works in a wide range of photographic media from color digital capture to platinum prints made with ultra-large format cameras. Years ago I brought him on to the staff of the magazine I used to edit, where he is still a Contributing Editor.) Gradually, he and I both realized that, independently, we were having pretty much the same reactions to the lens. What follows, cleaned up, amplified, reconstituted, illustrated and edited, is our conversation about it.
Mike Johnston: I’m pretty comfortable self-identifying as a lens nut—it’s been the focus of the gearhead side of my photographic hobby for many years—but I have to say that the more I use the new
Carl Weese: The main reason I began to work with the Pentax digital camera system, beginning about a year and a half ago with the K10D, was the clear commitment by Pentax to give us prime lenses designed for digital capture. The thing is, I just really, really, dislike working with zoom lenses. The remarkable trio of compact DA Limited lenses at 21, 40, and 70mm have some quirks and compromises as you’d expect with such unusual designs, but overall they are first rate performers optically. Thus, I expected to see good results from the DA 35mm f/2.8 Macro. Even so, I did a double-take the first time I keyed-up a 100% view of a capture from this lens. There was an intensity of detail and a transparency of rendering that I just hadn’t seen before. I pulled up the original RAW file of a capture that had made an excellent 15×22 inch print after interpolation. Side by side, my very first “get acquainted” captures with the new lens were unmistakably crisper.
Mike: I did that too. Right from the first I found myself “pixel peeping,” in Michael Reichmann’s popular phrase, and I’m not normally much of a pixel peeper. You have more experience with Pentax digital cameras than I do; I briefly owned a *ist DL2 that I disliked and de-accessioned promptly, and then I’ve had a loaner K20D for about three months now. At first it’s difficult to sort out the sensor from the lens. The K20D has two and a half times the pixels of my own 6-MP DSLR, so the K20D looks quite a bit better—it takes a lot more enlargement to get to the pixels, and the detail holds up a lot better. As I began to do my standard battery of test captures with the DA 35mm f/2.8 Macro, I started noticing how much the lens was contributing to the image quality. One of the first things I habitually do is a simple trial for light-source flare (Images 1 and 1-crop, both unsharpened, detail @ 300%).
This is the sort of trial I’ve done dozens of times, and I was expecting to see much more in the way of veiling glare near the sun, given the circumstances. The sun was really bright—it was a very bright day and this scene was uncomfortable to look at with the naked eye, even with the sun partially blocked by the trees. The thing that really impressed me about this capture is the bird. Even bombarded with bright direct light, with the subject in virtual silhouette, the lens managed to preserve the darker tonality of the phone line against the bird’s body and even some color and detail in the bird itself. That’s simply better than many lenses would do. At the time I thought, hmm, impressive. But then I thought, of course it’s just one test.
Carl: Here’s a photograph that isn’t quite so punishing, but it actually has to deal with about as much tonal range as you can find outdoors without looking straight into the sun (Image 2).
“How sharp is it?” seems to be the perennial first question about lenses. This lens is plenty sharp, and not just at close-up distances. The days when a macro lens had to sacrifice infinity or middle distance performance for close-up ability are long gone. Once we pass a certain threshold of “sharp enough,” though, sheer resolution isn’t anywhere near as interesting as other aspects of lens performance. There is something really special about the tonal rendering here. Look at the limitless variations of white in the clouds. Also the way the white aluminum siding is smooth up near the roofline, but weirdly wrinkled and crumpled down near sidewalk level. This complex information is conveyed in tones that all say “white.” As with your bird on the wire, the sidewalk diners in deep shade at the far right are clearly defined, though that may not be so apparent in the sRGB web file. Of course the lens isn’t working in a vacuum and the K20D’s sensor gets some credit for retaining all this tonal information, but something impressive is going on here that is different from captures I’ve made in similar conditions with other lenses. The exposure for this photo in harsh overhead sunlight was simply “sunny 16” (1/400th at f/8, ISO 100).
Mike: Yes, readers have to take our word for a lot of this. They’re seeing web JPEGs; we’ve seen full files at various magnifications. Anyway, as I threw test after test at the DA 35mm f/2.8 Macro, the same thing happened again and again: the lens would pass with more than flying colors, and I’d think, “Hmm. Impressive.” After a while, “hmm” gave way to “wow.”
As you know, I use the word “test” loosely—they’re really just trials, although I know enough about how lenses behave to get a lot of information out of trials. Distortion, corner performance, wide open performance, closeup performance, purple fringing, shadow detail, on and on. There are dozens of specific aspects of imaging that you can isolate and look at in lens trials, including half a dozen types of flare. And of course the purpose is just to find out, where is this lens strong? Where is it weak? This way you can avoid unpleasant surprises out in the field.
I remember once hiring a helicopter to do a job—photographing a beachside condo development for a brochure—and when I was done I still had fifteen minutes of chopper time left to kill. I asked the pilot to hover over the beach while I leaned out the side taking pictures straight down. It was pretty precarious (and I’m afraid of heights), so I opened the lens up and used a high shutter speed. Only after I saw all the results did I realize that I’d never shot that zoom wide open before, and it turned out it had pretty bad corner smearing. Oops. That’s the kind of surprise you really want to know enough to avoid.
Now I just try to “stress” the lens in trials (“test shots”) so I can learn about it. (Here’s a longer article I wrote about how to stress a camera lens that people can refer to for specifics.) It’s not a matter of obsessing or of one-upsmanship—I have lovely photos taken with a great many lenses, some of them not very well thought of—but as I progressed with the DA 35mm f/2.8 Macro, its aristocratic character, if you will, began to emerge. It simply took every challenge I threw at it effortlessly into stride. My admiration for it has grown and grown. I’m not confident enough to say that this lens has no weaknesses, but if it has any they’re certainly not easy to find! It has a lot fewer weaknesses than most lenses do.
Here’s the lens wide open (by mistake, I might add!), taken from a boat in low light as the sun went down (Image 3). The shadow detail is very good and the tonal properties just luscious. The file isn’t perfect—the edge of the tree line is just barely showing depth of field (DOF) issues (which are never as bothersome in clouds)—but let’s just say that I have no hesitation about using the DA 35mm f/2.8 Macro at maximum aperture.
Carl: Speaking of aristocratic character, we should mention one pleasantly old-fashioned thing about this lens, which is its build quality. This is a precisely machined assembly of metal and glass with a silky-smooth focusing action. Old-timers like us will be reminded of classic lenses from the past, and folks who’ve cut their teeth on recent wunderplastic zooms may be surprised at what a lens with really high-specification mechanicals feels like. It’s worth pointing out that this lens uses a plain AF mechanism driven by the camera body rather than the Pentax SDM motor-in-the-lens AF. I haven’t found any practical disadvantage to this.
Getting back to the pictures, I’m with you on testing. My “tests” really consist of heading out the door to use a new piece of equipment for the kinds of pictures I like to make, and then see how it does. If I run into something that looks like a problem—say obvious barrel distortion or color fringing—I’ll run a specific test to nail down that issue. For the most part I don’t do tests that aren’t really just attempts to make pictures.
We see a lot of pictures, especially online, that are over-saturated, over-sharpened, with exaggerated contrast, that just look generally garish. That approach is attention-getting, and it also can cover up some of the faults of a mediocre lens. Maintaining a rich but subtle description puts greater demands on the lens and sensor. In this photo (Image 4), the subject has no strong contrasts, no deeply saturated colors, no sharp edges. The “stuff” in the picture is all soft and round and old and weathered. The 35mm DA Macro Limited has done a great job of showing the textures of both broad and feathery leaves, thick faded blue paint on stone, yellowish-white paint on previously weathered wood, all without losing the character of the soft overcast light. Let’s see if that will show up in a 100% view screen grab (Image 4-crop) (unsharpened file from ACR):
A picture like this can’t have complete overall sharpness (at least not without a view camera). If you stopped down enough for that much depth of field you’d be way into the range where diffraction suppresses overall sharpness. Here, the drift from best focus to areas moving out of the depth of field is so smooth and gradual that material at the far right and back behind the window “read” sharper than they really are. That’s a lens quality I really value.
Mike: At the risk of becoming tiresome, I’d like to get back to my initial point about “delight and awe” as I progress through my trials. The Pentax 35mm DA Macro Limited surprises me at every turn. It’s so consistent in showing off its excellence that I ought to expect it, but often the opposite happens—even where I don’t expect it to do well, it rocks.
First of all, I’ve almost taken it on faith that it’s a decent macro lens. I’m not an expert on macro lenses because I don’t do macro work, but I have been very gratified by the performance it gives me in the near field. Here’s one relatively trivial example (Image 5).
The full file reveals that performance in this regard is just everything you could ask for. But as I say, I take for granted that a macro lens will be optimized for relatively high magnifications, so it should also do well in the near field as well. What I don’t always expect is that a lens optimized for high magnifications will also do well at infinity. It’s a subtle thing. I’ve even seen the differences in normal lenses; some of the old OM Zuiko lenses used to be corrected for closer focusing distances than, say, the old Zeiss Contax lenses were, and you could see that in careful trials.
As an establishing shot, take a look at this trivial snapshot of my backyard (Image 6). It’s a photo I’ve made dozens of times as I look at the way various lenses work. This happens to have been taken with the Zeiss 28mm f/2 ZK lens, itself certainly no slouch.
It’s very typical Zeiss performance, which is to say excellent, with that lovely coarse structure (say, 5 and 10 lp/mm) high contrast that Zeiss is noted for, and rich, subtly variegated colors. I could happily live with this fine lens on APS-C.
But now look at a pixel-peeping enlargement of a similar (but sunlit) shot from the Zeiss 28/2 ZK (Image 7).
Looks fine, right? About what you’d expect of an above-average lens: good detail, good contrast in those dark shingles, a little blue replacement in the wires on the top left and the sparse leaves and branches against the sky (in that hole in the trees), but still perfectly unobjectionable resolution. You’re seeing individual bricks. This is unsharpened, and I would expect a detail like this to sharpen up nicely. No surprises.
But now look at the same detail from a photo taken with the Pentax 35mm DA Macro Limited just a minute or two later (Image 8).
Here’s a situation in which I would naturally expect the 35mm DA Macro to do somewhat less well, but then it just cheerfully stomps the Zeiss lens. There’s less blue replacement in the sparse leaves and twigs, the contrast in the dark shingles is better (and compare those even less contrasty foreground shingles), the color is more vivid, the edge of the roofline is simply sharper, and you’re seeing even better resolution of the bricks and more contrast between the bricks and mortar. (I should add that these are focus bracketed, too, so the difference you’re seeing is not focus. Approximately the same difference holds in closer objects as well.) Granted, I know that the parameters are different: the Zeiss lens will cover 35mm, and it’s one stop faster and 7mm wider, and all those capabilities are somewhat more difficult to design for. It’s not a direct “comp” and thus not a perfectly fair comparison. Still, traditionally Zeiss designers correct closer to infinity and macro lenses are typically corrected better for the near field, and I would not have been in the least surprised if the Pentax lens failed to quite come up to the performance of the Zeiss, or just matched it. Instead, I’m left (again) going, “wow.” And that’s just the story of the way it’s been for me with this lens.
Carl: This lens is so good that I have just one (unfair but very real) complaint—it’s not the right focal length for me. Thirty-five millimeter on APS-C (52.5mm equivalent) is just too long for me to use as my standard. The one lens I want if I’m using only one, the lens that I’ll always start out with on the camera if I’m carrying a full set of lenses: that lens needs to be shorter. My complaint is that I want this to be just one lens in a whole line of Pentax DA Limited standard (non-compact) primes.
Pentax already has a line of DA Limited lenses, the 21/40/70mm compacts, or “stack of pancakes,” and no other manufacturer has a line of medium-length designed-for-digital primes. These are remarkable lenses that I’ve used for most of my work over the past year and a half. Pancake designs require compromise. Downsides to the trio that can be traced directly to the quest for miniaturization include slow maximum aperture for the shorter two, illumination falloff (vignetting) that doesn’t clear until f/5.6 for the longer two, and annoying barrel distortion with the shortest one. All three have miniscule focus rings with a weird lack of damping (physical feedback) and extremely steep (hair-trigger) helicoids. Combined with the dim maximum apertures and short (in absolute terms) focal lengths, this all makes manual focusing no fun at all, and often appears to make the AF system strain. The new 35mm Macro is big compared to the amazing 40mm pancake, but compared to an equivalent 55mm f/2.8 macro lens for 35mm format it seems miniature itself. There’s nothing clunky or bloated about this lens. It packs a focusing mechanism that reaches from infinity to 1:1 that responds fast to the camera’s AF system and also feels silky smooth in manual focusing with absolutely no queasy-feeling looseness. The robust focus ring is easy even for large hands to deal with.
Mechanically, this lens hits a Goldilocks point for me. It’s not so big that if I raise the camera everyone on the block knows a photographer is about to take a picture, and it’s not so small I can’t get my fingers on the controls. It’s just right. It also has virtually no rectilinear distortion, no noticeable vignetting even wide-open, and along with crisp AF performance on the K20D, in manual focus (very useful when actually using its close focus abilities) it has the confidence-inspiring mechanical feel of the best classic manual focus lenses.
I want several more family members. I want an 18mm (24mm-e) f/2. I really want a 23mm or 24mm (35mm-e) f/2, which would become my standard lens for digital capture just as the 35mm Summicron was my standard lens on 35mm film for decades. While I’m at it, I’ll also ask for a DA Limited Standard lens that fills the role of the classic 85mm f/1.8 for 35mm film. It doesn’t hurt to ask.
Mike: Seconded. The 35mm DA Macro Limited is the perfect size and weight, and handles beautifully. Like you, I like normal lenses to be as small as this but I don’t need them to be smaller. I also agree that a somewhat shorter version is called for, all the more urgently in light of the absolute top-class performance of this one. There’s currently a 30mm on Pentax’s lens roadmap, and that seems almost tragic to me—30mm is just not enough shorter than 35mm on APS-C to make a meaningful difference. I wonder how we could communicate to Pentax just how badly we want a lens within a millimeter or two of 25mm! And how much more Pentax itself needs a ~25mm than a 30mm. That’s looming as a hole in its prime lineup, and it’s a significant hole since it’s “home” for everyone who ever photographed primarily with a 35mm normal on 35mm format, for example, older (ahem) photographers like you and me who’ve lived with a 35mm Summicron on a Leica M for any length of time.
Still, for what it is—a 50mm equivalent lens for APS-C with macro capability, that can readily be used as a general-purpose normal—the SMC Pentax DA 35mm f/2.8 Macro Limited is a paragon. It really is just beautiful, and will gratify…no, it will spoil anyone who likes the very best optical quality and appreciates what truly outstanding lenses can do. It ranks right up there with the best lenses I’ve ever used in any format.
- Photo.net Pentax Discussion Forum
- Pentax DSLR Guide to Cameras and Lenses
- Pentax 21/40/70 Limited Lens Review
About the Authors
Carl Weese, a longtime professional photographer, art photographer, and educator who specializes in ultra-large-format platinum/palladium photography, is a Contributing Editor of Photo Techniques magazine and co-author of The New Platinum Print. He writes regularly for The Online Photographer. See his web site at http://www.carlweese.com.
Visit Mike Johnston’s daily photo news web site The Online Photographer at www.theonlinephotographer.com.
Text and photos ©2008 Mike Johnston and Carl Weese.