Wedding planner

When it comes to shooting at an event as important as a wedding, two things about a lens are paramount: low-light performance and the ability to isolate focus on the bride. A big aperture will help you with both requirements. This premium-quality lens has a light-gathering f/2.8, 9-bladed aperture, for soft, smooth out-of focus backgrounds that make your foreground subject leap to life. With a zoom range that extends from portrait length to medium-long telephoto, you'll be able to capture candid moments from a distance as the sun goes down. Weather-resistant, dust-resistant construction makes this lens the perfect companion to the Pentax K-5 weather-resistant digital SLR. Between the two, you'll have a combo that's built for bringing home the elusive shot under challenging circumstances.

Aspherical glass elements, plus special Pentax coatings, make your images as sharp and artifact-free as they can be. The Quick-Shift focus system allows instant on-the-fly switching from auto to manual focus.

Product Highlights:

  • Pentax DA Star KAF2 50-135mm f/2.8 ED telephoto zoom lens with 35mm equivalent of 76.5-207mm
  • compatible with Pentax K-mount digital SLR and hybrid cameras, especially the weather-resistant Pentax K-5
  • ED (extra-low dispersion) lens elements correct chromatic aberration for excellent image quality and sharpness
  • tightly sealed, weather-resistant and dust-resistant construction enhances durability for use in both rainy and dusty conditions
  • SDM supersonic-motor autofocus system is smooth, quiet and fast
  • constructed of 18 elements in 14 groups
  • minimum focus distance: 39-5/8"
  • minimum aperture: f/22
  • filter size: 67mm
  • lens is 5-13/16" long, 3" in diameter
  • weight: 24.2 ounces
  • supplied accessories: front and rear lens caps, lens hood, soft case
  • warranty: 1 year
  • Our 60-day money-back guarantee

Hands-on research

What's in the box?

Download owner's manual

  • smc Pentax-DA Star 50-135mm f/2.8ED [IF] SDM lens (with attached front and rear lens caps)
  • PH-RBK 67mm lens hood (installed on lens)
  • Operating Manual
  • Notification of Change of Company Name sheet
  • Pentax Worldwide Service Network sheet
  • Serial Number Card

Features and Specs

Brand Compatibility Pentax
Image Stabilization No
Focal Length 50-135mm
Maximum Aperture F2.8
Weight 24.2 ounces
Parts Warranty 1 Year
Labor Warranty 1 Year

Product Research


Overview: The high-performance smc Pentax-DA Star 50-135mm F2.8ED [IF] SDM lens is for standard to medium long-range applications.

Weather Resistant: The tightly sealed, weather-resistant and dust-resistant construction enhances durability for use in both rainy and dusty conditions.

Lens Mount: The lens has a KAF2-mount, and can fit Pentax D-SLR and interchangeable lens cameras with KAF, KAF2 and KAF3 mounts. This includes the Pentax K-5 and K-01 cameras.

SDM Focus System: The lens is equipped with a supersonic motor for achieving smooth and quiet autofocusing. It has a focus mode switch on the barrel for changing from autofocus to manual focus. The switch allows you to leave the camera in the autofocus mode, and change modes on the lens.

ED Glass: The lens has three Extra-low Dispersion (ED) glass lens elements to compensate for chromatic aberrations. The ED glass and original lens coatings offer superior contrast, clarity, and edge-to-edge sharpness.

Lens Hood: The lens comes with the PH-RBK 67mm lens hood for keeping unwanted light from entering the lens, and for protecting the front of the lens. It has a PL filter window which can be opened for facilitate the manipulation of the circular polarizing filter when the lens hood is attached. The hood can be reverse-mounted on the lens for storage. When installed, the hood adds approximately 3-5/16" to the overall length of the lens.


  • Focal Length: 50-135mm
  • 35mm Equivalent: 76.5-207mm
  • Lens Construction: 18 elements in 14 groups
  • Mount Type: KAF2-mount
  • Maximum Aperture: F2.8
  • Minimum Aperture: F22
  • Maximum Magnification: 0.17x
  • Angle of View: 31.5°-11.9°
  • Minimum Focus Distance: 3.3' (39.6")
  • Lens Hood: PH-RBK 67mm (included)
  • Filter Diameter: 67mm
  • Dimensions:
    • Diameter: 3.002"
    • Length: 5.793" (6.24" w/caps)
    • Weight: 24.2 ounces (27 oz. w/lens hood)

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