Pentax DA★ 55mm F1.4 SDM review

The Pentax DA* 55mm F1.4 SDM is a fast portrait lens for APS-C Pentax D-SLRs and a premium option for Pentax fans

Pentax DA★ 55mm f/1.4 SDM review
(Image: © Rod Lawton)

Digital Camera World Verdict

The Pentax DA* 55mm F1.4 SDM is one of Pentax's more modern DLSR lenses, boasting an integrated SDM ultrasonic motor for faster, quieter AF than most Pentax lenses of old. It's designed for APS-C cameras, where it offers an effective focal length of 85mm approx, which makes it a handy portrait lens for these cameras. Its performance is broadly good, but the AF is not silent and the edge performance is average. For a premium lens, we might have hoped for better, but it's not bad nonetheless.


  • +

    Ideal 'portrait' lens on APS-C

  • +

    F/1.4 maximum aperture

  • +

    Quiet(er) SDM autofocus


  • -

    Soft edges

  • -

    Not that sharp wide open

  • -

    Purple fringing round highlights

  • -

    Seems quite expensive

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The Pentax DA★ 55mm F1.4 SDM sounds like a nifty fifty, but it’s actually designed for Pentax’s APS-C DSLRs, like the new Pentax KF (which is the camera we used to test it). On an APS-C camera, its focal length is equivalent to 84.5mm, so really this is a portrait lens.

The star in the name indicates one of Pentax’s premium quality lenses, and the ‘SDM’ denotes a Supersonic Drive Motor built into the lens itself. This should give it smoother, faster operation than the body-based motor used for many other Pentax lenses. 

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Rod Lawton

Rod is an independent photography journalist and editor, and a long-standing Digital Camera World contributor, having previously worked as DCW's Group Reviews editor. Before that he has been technique editor on N-Photo, Head of Testing for the photography division and Camera Channel editor on TechRadar, as well as contributing to many other publications. He has been writing about photography technique, photo editing and digital cameras since they first appeared, and before that began his career writing about film photography. He has used and reviewed practically every interchangeable lens camera launched in the past 20 years, from entry-level DSLRs to medium format cameras, together with lenses, tripods, gimbals, light meters, camera bags and more. Rod has his own camera gear blog at but also writes about photo-editing applications and techniques at