Pentax DA 12-24 f4.0

If you were to design the perfect landscape lens, you couldn’t do much better than the Pentax DA 12-24 f4.0. Given the inherent limitations of lens technology, it’s hard to imagine a better landscape lens for APS-C cameras. The focal range is eminently well suited for capturing the splendor of the great outdoors, giving one the 35mm equivalent of an 18mm to 36mm lens — in other words, right in the sweet spot for vista-type landscape shooting. This lens will give you deep, rich, blue skies without a polarizer; and it will capture shades of dark, verdant green that elude many other lenses. And you’ll be hard pressed to find a more contrasty zoom lens; it produces results comparable to the clarity slider in Lightroom without the halos. All in all, the lens seems tailor-made for producing spectacular landscape images:

Of course, as perfect as this lens may be for landscape work, that doesn’t mean it’s entirely free from imperfections and flaws. No lens, and in particular no zoom lens, can ever be immaculately perfect. The chief flaws of the DA 12-24 are its less then stellar corner to corner sharpness at infinity focus and its tendency to produce various chromatic aberrations leading to blue, purple, magenta and green fringing toward the corners of the image:

Yet these issues are, in the vast majority of cases, not nearly as critical as might be thought, since the most egregious aberrations can easily be removed, or at least severally limited, in Lightroom:

The softness toward the corners at infinity focus is almost certainly a product of field curvature. Yet, curiously, curvature issues don’t affect border to border sharpness at closer distances. Between 2 and maybe 20 feet, the DA 12-24 is remarkable sharp, corner to corner. Consider the following image, taken at the wide end of the lens:

Now notice a 100% crop of the corner:

That’s impressive performance for an ultra-wide angle zoom lens.

Like most Pentax zoom lens, resolution is at its peak toward the wide end of the lens. It loses a bit of resolution at the long end of the lens, but it’s not enough to cause serious concern. At 24mm, the DA 12-24 is still a heck of a lens. Note the excellent micro-contrast (just the sort of contrast difficult to simulate in post) and the wonderful color of the image:

The other minor issue with the DA 12-24 involves distortion. An ultra-wide zoom will exhibit perspective distortion, end of issue. Note, in the following image, the angle of the trees, particularly as you scan from one end to the other:

Thus are the “real world” distortion effects manifested by the lens at 12mm. By 24mm, the distortion is nearly absent, as follows:

The DA 12-24 is not an inexpensive lens, running well over $750 brand new, and over $600 used. It tends to run $100 to $400 more than third party alternatives such as the Tamron 10-24 or the Sigma 10-20. Is it worth the extra price? Well, for high-end landscape work, yes. This is a lens optimized for landscape work: it excels precisely with those type of colors against which other lens struggle. Lenses sometimes struggle with dark greens. Many lenses, including the Sigma 10-20, tend to emphasize the yellow in green foliage at the expense of the dark green. Only the DA 12-24 gets it right, letting you capture the rich greens of mountain and forest landscapes:

It’s pretty damn good with capturing blues as well: