A venerable, high-speed prime takes on a new role for Pentax-loving portrait
This high-speed, normal prime ($199, street) has been around for a decade. Why test it now? No other lens in the current Pentax catalog can throw backgrounds into creamy defocus like this. Even better, on a Pentax K10D, K100D, or K100D Super DSLR, it scales up to a medium-tele 75mm, a fine choice for portraits. Better still? The low price.
A half-inch shorter and several ounces lighter than comparable Canon and Nikon 50mm f/1.4s, this full-framer predates digital. The small, rubber-clad, manual-focus ring's turning action is a bit rough. Distance scales are large and easily legible; ditto for the depth-of-field scale (remember those?). The AF action on our test camera, the Pentax *ist DL, was rapid and quiet.
IN THE LAB
SQF data showed sharpness and contrast in the Excellent range. DxO Analyzer 2.0 tests found only Imperceptible barrel distortion (0.08%), on par with the Nikon and better than the Canon, with Slight barrel distortion. Light falloff was gone by f/2, much better than Nikon's f/1.4, which showed vignetting to f/4. Its maximum magnification ratio at the 16.75-inch close-focus distance was 1:6.0 -- beating not only the Canon and Nikon but Pentax's claim of 1:6.6.
Sharp, bright, and practically distortion-free, this lens deserves a place in any Pentax shooter's bag. Wedding photographers, in particular, will like it for its defocused backgrounds, low-light performance, and focal length well suited to two-up verticals.
50mm (51.93mm tested), f/1.4 (f/1.45 tested), 7 elements in 6 groups. Focusing turns 140 degrees clockwise.
• Diagonal view angle: 47 degrees.
• Weight: 8 oz.
• Filter size: 49mm.
• Mounts: Pentax AF.
• Street price: $199.