Pentax K 28 f3.5

The Pentax SMC 28mm f3.5 lens was introduced in by Pentax in the mid-seventies. It was Pentax’s first K-mount 28mm lens. Many of the initial K-mount lenses were based on the Takumar m42 screw-mount lenses that preceded them, but this 28 f3.5 was a newly designed lens, using 8 elements. This is a rather large lens for a 28mm f3.5 optic, weighing over 9 ounces and reaching nearly 2 inches in length . The successor M series 28mm f3.5 lens used only 6 elements and was barely an inch and a quarter in length. This early K series 28mm lens represents a unique design among Pentax 28mm lenses. Unfortunately, the lens had only a brief two year run.

From first hand experience with the lens, it appears likely that the lens was optimized for landscape use. Lenses of that vintage often suffered a loss of sharpness toward the corners. Resolution tests, however, demonstrate that the K 28/3.5 as one of the sharpest lens, corner to corner, that Pentax had produced up to that time. It is likely that, when this lens was designed, efforts were made to improve corner to corner sharpness. Perhaps that explains the extra elements in an f3.5 lens. Pentax was not trying to manufacturer a slower, less expensive wide angle lens for Pentax shooters on a budget. While it may be a “slow” lens, the K 28/3.5 is not a budget lens. Landscape shooters don’t need an f2 or f1.4 wide angle lens. They just need a lens that performs well between f5.6 and f16. And between these apertures, the K 28/3.5 really shines. Not only does it feature impressive border to border sharpness, but it may well be one of the most contrasty wide angle lenses in Pentax’s line-up. Indeed, the lens renders like none other. Images not only have a contrast that sharply delineates and gives depth to various objects within the image, but it also produces rich color, particularly along the blue-purple end of the spectrum:

The lens even does well in bright sunlight, bringing a brightness, luminosity, and clarity to subjects that might otherwise be thoroughly overwhelmed by glaring sunlight. Notice the rich blues in the following photograph, notice how the rock positively glows in the lights, and notice, as well, as how well the crags of the rock are rendered, imbued with both depth and realism:

The lens tends to be little cooler and darker than most other Pentax lenses, favoring rich, contrasty hues, which works well in landscape photos, particularly those with water in them. With its unique rendering, the Pentax K 28 f3.5 makes an excellent speciality lens for landscape photographers seeking glass with unique rendering characteristics that can add life to photographs of lakes, waterfalls, and scenic coastlines: