The fastest Pentax telephoto lens to the test: Pentax smc DA Star 200mm F2.8 ED (IF) SDM

Tuesday May 15 2012

Lens Review
The fastest Pentax telephoto lens to the test: Pentax smc DA Star 200mm F2.8 ED (IF) SDM

The PENTAX DA Star 200mm F2.8 ED (IF) SDM is the fastest telephoto lens in Pentax’s high-end product range. For example, on an APS-C like the Pentax K5, its focal length is equivalent to a 300mm on a full-frame camera. With its weather- and dust-resistant construction and fast ultrasonic autofocus, it could prove a great companion for wildlife and sports photographers.

Pentax also included three extra-low dispersion (ED) elements to deal with chromatic aberration, so let’s see how the PENTAX DA Star 200mm F2.8 ED performs in term of image quality.

Measurements

PENTAX DA Star 200mm F2.8

The strong points of the Pentax DA Star 200mm F2.8 ED (IF) SDM:

  • Zero distortion.
  • Very good behavior with respect to vignetting; zero vignetting from f/4 onwards.
  • Good correction of chromatic aberrations.
  • SDM autofocus.

The questionable point of the Pentax smc DA Star 200mm F2.8 ED (IF) SDM:

  • The lens transmission is 0.4EV less than the manufacturer’s announced transmission measurement.

Comparison

Pentax smc DA Star 200mm F2.8 ED (IF) SDM vs Pentax smc PENTAX DA 50-200mm F4-5.6 ED mounted on a Pentax K200D

Comparison at F=200mm:

The advantages of Pentax smc DA Star 200mm F2.8 ED (IF) SDM:

  • Much brighter, with a gain of nearly 2EV.
  • Better sharpness at the same focal distance and aperture (i.e, 200mm opened to 5.6). In fact, the sharpness at 200 mm opened to 2.8 is the same as or even slightly superior to the sharpness measured for the 50-200mm at 200mm opened to 5.6, despite the difference in aperture.
  • Better handing of distortion.
  • Better handing of vignetting.
  • SDM autofocus.
  • Circular aperture.

The advantages of the Pentax smc PENTAX DA 50-200mm F4-5.6 ED:

  • More compact.
  • More versatile.
  • Lighter.
  • More economical.