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Pentax smc DA 645 25mm f/4 AL (IF) SDM AW Lens

You Pay: $4,996.95
Product Highlights
  • Ultra Wide Angle Lens for Pentax 645D
  • Equivalent to 19.5mm Lens in 35mm Format
  • Aero Bright Coating Reduces Aberrations
  • SDM Autofocus for Fast and Quiet Results
  • Quickly Switch from Auto to Manual Focus
  • Rounded Aperture Blades for Superb Bokeh
  • Inline Filter Design
  • SP Coating Protects Lens from Elements
  • Weather and Dust Sealed for Reliable Use

The Pentax smc DA 645 25mm f/4 AL (IF) SDM AW Lens is a wide angle lens for use with the Pentax 645D digital camera. Its 25mm focal length is equivalent to 19.5mm in 35mm format and provides you with an angle of view of 95°. The combination of such a wide angle focal length and a minimum focus distance of 1.31' / 0.4m gives this lens a tremendous hyperfocal distance, ideal for landscape photography and other broad scenes.

The lens features Pentax' SDM autofocus system for quick and quiet performance. It is also coupled with the Quick Shift focus system for disengaging the AF motor, allowing instant switching between auto and manual focus modes.

The lens elements also features an Aero Bright coating for reducing aberrations inherent to the wide angle design as well as providing greater light transmission to the camera's sensor. The SP coating on the front element helps to prevent dust and oils from obscuring the image and makes it easier to clean the surface. The entire lens construction is weather and dust sealed for reliable operation in harsh conditions.

25mm wide angle lens is compatible with Pentax 645D and provides a 95° angle of view.
SDM autofocus system provides highly accurate, fast, and quiet performance.
Quick Shift focus system allows you to disengage the AF motor for seamless, instant transitioning between auto and manual focus modes.
Aero Bright lens coating helps to reduce aberrations and promotes greater light transmission.
Inline filter design permits the use of 40.5mm drop-in filters for use within the lens body; screw-in type filters are not compatible due to the convex lens design.
9 rounded blade diaphragm design provides an aesthetic out of focus quality that is especially noticeable when photographing with wider apertures.
SP coating protects lens elements from dust and oils and makes it easier to clean.
Weather and dust sealed construction gives reliable performance when working under less-than-ideal conditions.
Focal Length 25 mm
Aperture Maximum: f/4
Minimum: f/32
Camera Mount Pentax 645
Angle of View @ Infinity 95°
Minimum Focus Distance 1.31' (.40 m)
Diaphragm Blades 9
Elements/Groups 12/8
Magnification 0.11x
DOF Scale Yes
Distance Scale Yes
Autofocus Yes
Tripod Collar No
Filter Thread 40.5 mm 1
Please Note:

Inline/drop-in filter design

Weight 36.7 oz (1040 g)
Dimensions Approx. 3.54 x 5.85" (90 x 148.5 mm)
Pentax smc DA 645 25mm f/4 AL (IF) SDM AW Lens
  • Push-On Cap for Pentax DA 645 25mm f/4 AL (IF) SDM AW Lens
  • Rear Lens Cap
  • S100-200 Soft Lens Case
  • Inline Lens Filter 40.5mm (Normal)
  • Inline Lens Filter 40.5mm (C-PL)
  • 1-Year Limited Warranty

    by PowerReviews
    Pentaxsmc DA 645 25mm f/4 AL (IF) SDM AW Lens

    (based on 2 reviews)

    Ratings Distribution

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    • 1 Stars



    Reviewed by 2 customers

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    (4 of 4 customers found this review helpful)


    Amazing lens, one of my favorites

    By AlexLA

    from Los Angeles

    About Me Pro Photographer

    Verified Reviewer


    • Durable
    • Fast / accurate auto-focus
    • Great Resolution
    • Strong Construction
    • Weather sealed


    • Heavy

    Best Uses

    • Indoors/Low Light
    • Landscape/Scenery
    • Night Photography

    Comments about Pentax smc DA 645 25mm f/4 AL (IF) SDM AW Lens:

    They say that "you get what you pay for", and with this lens, you get a lot! The drop-in filter is a great solution to the otherwise protruding front element, and works well with polarizers. This lens is sharp! It resolves amazing detail and focuses quickly. It is a beast of a lens, no doubt. I can see how landscape photographers love this lens, but architectural photographers should appreciate it too. This, and the 90mm are simply the best 645 system lenses available from Pentax today in my opinion.

    • Was this a gift?:
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    (9 of 9 customers found this review helpful)


    Great super weide angle

    By Hugo

    from Salt Lake City, Utah

    About Me Photo Enthusiast


    • Durable
    • Easily Interchangeable
    • Fast / accurate auto-focus
    • Nice Bokeh
    • Rugged
    • Strong Construction


      Best Uses

      • Landscape/Scenery

      Comments about Pentax smc DA 645 25mm f/4 AL (IF) SDM AW Lens:

      This is a fantantic super wide angle medium format digital lens for Pentax. Images are sharp. The focus is fast. Lens is weather sealed. I really like the small (40.5mm) drop in filter which can be rotated if needed when using a polarizer. As far as I know, this is the widest angle medum format digital lens available for any system. I use it for landscapes for David Muench type "near far" images.

      • Was this a gift?:
      • No

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      Filters & Filter Kits

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      B+W -  40.5mm Circular Polarizer MRC Filter
      • You Pay: $75.00

      40.5mm (inline filter, not front mount)

      Cases & Wraps

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      OP/TECH USA -  11" Soft Wrap (Forest Green)
      • You Pay: $10.95

      Care & Cleaning

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      Pearstone -  Lens Cleaning Tissue Paper (100-Sheets)
      • You Pay: $3.14
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