Pentax M 28 f2.8

If graded in absolute terms, the SMC Pentax M 28 f2.8 wide angle lens would have to be rated a fairly decent lens. Optically, it has no serious flaws. It has decent resolution, decent color rendition, decent contrast. Yet somehow, the lens fails to inspire. It does not come up to the usual high Pentax standards. It is merely a good lens, nothing more. Beyond its small size and inexpensive price on the used market, there is nothing special about this piece of glass. Along with the Pentax M 50 f2.0 and M 35/2.8, it is one of the least distinguished of Pentax’s prime lenses. Perhaps Pentax was aware of this, as the M 28/2.8 is one of the only lenses that Pentax redesigned and replaced while still in production. There are in fact two versions of this lens. The later version, which was introduced shortly before Pentax released its new auto exposure “A” series of lens, seems to be an A series lens without A series features. It is speculated that Pentax made this switch because they ran out of parts for the older M version. But the very fact that Pentax would make a new version of the lens for the A series indicates a lack of satisfaction with the lens.

Optically, there is nothing distinctive or special about the lens. Its color rendition, although decent enough, fails to stimulate. Its resolution, though pretty good, is hardly stellar. Its micro contrast, while serviceable, does not measure up to the standards set by Pentax in most of its other prime lenses. If this were the only Pentax lens you had ever used, you would never know there was anything special about Pentax glass. Unfortunately, this was one of Pentax’s most popular lenses in the late seventies and early eighties. Along with the equally uninspiring M 50/2, it was the lens most likely to be paired with the K1000, Pentax’s popular “learner’s” camera used by so many fledgling shutterbugs to master the art of SLR photography. How many young photographers in the eighties and even nineties learned photography through Pentax without learning anything about Pentax itself, or the glories of SMC Pentax glass? The M 28/2.8 may have to take credit for reinforcing the stereotype that Pentax was merely a value brand best suited for students and penny pinching shutterbugs.

On digital cameras, the lens produces nice but uninspiring images:

Resolution is more than adequate, as can be seen in this 100% crop:

There’s more, however, to a lens than mere resolution. The M 28/2.8 lacks the microcontrast and the distinctive color rendition of Pentax’s other lenses:

All these images were heavily post-processed to improve color and contrast. Again, they’re not bad; but a lens like the K 28/3.5 or the DA 12-24 easily produces superior results:

The main selling point of the M 28/2.8 is that its cheap and compact. The lens is not much bigger than a pancake lens and weighs only 156 grams. But the fact of the matter is, the M 28/3.5, it’s slightly slower and heavier brethren, is a better lens; and its forbear, the K 28/3.5 is significantly better. So, in conclusion, the Pentax 28mm f2.8 is a good lens, but doesn’t quite live up to Pentax’s usual high standards in prime lenses.