Pentax DA 16-85 f3.5-5.6

The HD Pentax DA 16-85mm F3.5-5.6 ED DC WR is a standard zoom for Pentax APS-C DSLR cameras. The lens weighs a little over a pound and features one extra-low dispersion element and three aspherical elements. It covers a range from wide angle (24mm FF equivalent) to moderate telephoto (130mm FF equivalent). The lens also features Pentax’s newest HD multi-coating technology and eleven seals to provide “weather resistance.”

This “HD” coating is a relatively new technology, introduced very recently by Pentax as a replacement for their venerable SMC coating. As Ricoh, the parent company of Pentax, explains:

Compared with conventional multi-layer coatings, the new multi-layer HD Coating,* exclusively developed by PENTAX, offers much improved light transmittance and a much lower refractive index. Because it minimizes reflections, it delivers sharp, clear images free of flare and ghost images, even under demanding lighting conditions such as backlight. This coating assures optical performance almost equal to Aero Bright Coating, another PENTAX-exclusive lens coating process made possible by advanced nanotechnology and applied to higher-class lenses.

Ricoh provides an interesting, though also puzzling, graph which illustrates the benefit of the HD coating over “Conventional Multi Coating.” Does “Conventional Multi Coating” refer to the Pentax’s older SMC technology? Or does it refer to Pentax’s ghostless coating technology introduced in 1997? This is not explained. But here’s the graph, in any case:

Essentially, the horizontal axis, measured in wavelength, corresponds to the color spectrum. 380 nm to 440 nm roughly corresponds to Violet, 440 nm to 485 nm roughly corresponds to blue, 485 nm to 500 nm roughly corresponds to aqua, 500 nm to 565 nm roughly corresponds to green, 565 nm to 590 nm roughly corresponds to yellow, 590 nm to 625 nm roughly corresponds to orange, and 625 nm to 740 nm roughly corresponds to red.

Keeping all this in mind, what does graph tell us? Namely, that the HD coatings transmit a larger percentage of the color spectrum (because there’s less “reflectance”), especially the blue through yellow part of the spectrum. This means if you’re photographing with HD lenses (all else being equal), your sensor will capture more color information, particularly blue, aqua, and yellow, than if you were shooting with a lens featuring “Conventional Multi Coating.”

The HD coatings should also improve contrast and reduce flare. Coatings are an important factor in the image quality of a lens and any improvement is welcome.

When the DA 16-85 was first announced, many Pentaxians complained quite bitterly at the slow, variable aperture and the $799 price tag. They assumed, wrongly as it turned out, that a slow aperture lens must be a mediocre “kit” lens. It never occurred to them that a slow lens can be just as sharp and contrasty as a fast lens. Lenses involve tradeoffs. And what the DA 16-85 loses in lens speed it gains in focal length. Nor does it sacrifice, in doing so, sharpness and contrast.

Let’s look at some images and see how the lens performs. Before we start, a word of warning. Most of the images below are “real world images” in the sense that they were not taken as part of a test of the lens’ capabilities. The point is to provide a sense of what this lens is capable in real use, particularly when used to photograph landscapes. There are other review websites that will give you (allegedly) more scientific tests, of varying accuracy, regarding the resolution of this lens. I don’t provide that here, opting for another approach. The downside of my approach is that I am stuck with whatever images I can find in my library. Since I rarely shoot this lens wide-open, I can’t really provide any images illustrating what the DA 16-85 can do when shot at the widest available aperture. All of the samples here will show what the lens can do at f8, which is what those of us who are landscape shooters will mostly shoot at.

Let’s start with this image of a massive cedar taken at 16mm and f8:

The center crop:

And the (right) corner crop:

While there’s definitely a loss of resolution in the corner, this is still pretty good performance for a zoom lens with more than a 5x range. Here’s another sample:

The center crop:

The (upper right) corner crop:

Again, good, if not great corner performance. Actually, there really isn’t anything to complain about here. Nearly all standard zooms, even the expensive Canon and Nikon FF f2.8 standards, are sharper in the center than along the edges and corners. This is especially true at the wide end of standard zoom lenses.

Now an example from 26mm, also shot at f8:

The center crop:

The corner crop:

Another 26mm example:

Center crop:

Edge crop:

Both of these examples show sharp centers, less sharp corners and edges. Still very fine performance for a 5x zoom.

Now for example taken at 35mm, f8:

Center crop:

Edge crop:

Pretty much the same as at other focal lengths. What do we find at 48mm?

Center crop:

Edge crop:

As we get it to longer focal lengths, we run into another problem: narrower depth of field. In the above image, the corner is much close to the camera than the center. So is it less sharp due to this proximity, or is it less sharp due to loss of performance toward the edges? In any case, it’s only the far corner that’s “soft,” so maybe it doesn’t matter all that much.

Let’s look at another example, this time at 53mm, with the corner pretty much at the same focal plane as the point of focus:

The focus point is on the tree, rather than anywhere in the center of the image. So let’s look at the far left bottom corner:

The leaves on the right (further from the corner) are “soft,” because their out of the plane of focus. Yet the leaves closer to the tree are pretty good. In the very far corner, we can see a loss of resolution, but it’s still pretty good.

Next, let’s peruse an image shot at 68mm:

Center crop:

Corner crop:

Pretty much same result as at 58mm. Now let’s see what the lens does at the long end, at 85mm:

Center crop:

Corner crop:

One more example:

Center crop:

Corner crop:

Here we run into that problem mentioned earlier of finding corners in the plane of focus. Even so, it seems that the first set of shots featured a sharper corner. Why would this be? As far as I can make out, it’s because of the greater distance. The second shot is four, five times further away. And in general I have noted that distance affects corner sharpness of this lens at the long end — for whatever reason.

Nonetheless, centers and most of the frame are sharp at 85mm, regardless of distance. Consider this image of a boat:

To sum up: the DA 16-85 is a commendably sharp, contrasty lens. Like most standard zoom lenses, it is sharper in the center than along the edges and in the corners. It maintains its general excellent performance throughout its range, although at the long end the edges and corners may be somewhat less sharp, especially at longer distances. Chromatic aberration is fairly minimal, and when it occurs (mostly at wider focal lengths), it nonetheless cleans up pretty well in Lightroom. Barrel distortion does exist at the wide end, which is precisely what one would expect in a zoom lens of this type. In short, this lens performs about as well as one could reasonably hope considering its 5x plus range.

The DA 16-85, with its generous focal range, its slow aperture, and its weather sealing, makes a perfect all-in-one landscape lens. Indeed, it may be the only lens you need for landscape photography. It’s HD coatings help create images with great contrast and excellent color, and its slow aperture keeps the lens at a reasonable size and weight. If you’re looking for a standard zoom for landscape photography in the K-Mount, there is currently no better option.

More sample images (all but one taken at f8), starting with 16mm:

At 18mm:

This is shot at f4:

At 23mm:

At 26mm:

At 28mm:

At 35mm:

At 39mm:

At 43mm:

At 48mm:

At 53mm:

At 60mm:

At 75mm:

At 85mm: