B&H Photo Video Pro Audio The Professional's Source 800.606.6969 / 212.444.6615
0 $0.00
Your cart is currently empty

You have 0 items in your cart

View Cart & Begin Checkout

Sigma Super Wide Angle 20mm f/1.8 EX Aspherical DG DF RF Autofocus Lens for Pentax AF

B&H # SI2018PAF MFR # 411109
No Longer Available

Questions? Ask our experts:

This 20mm is a Super wide-angle lens with a large aperture of f/1.8 and angle of view 94.5°. It has Macro focusing capability with a minimum focusing distance of just 7.9", for a reproduction ratio of 1:4. The 9-bladed iris diaphragm obtains beautiful out of focus image characteristics. Aspherical lens elements in the front & rear lens groups minimize distortion, spherical aberration and astigmatisms. The lens has non-vignetting optical construction in order to obtain adequate peripheral brightness with wide apertures-especially desirable for digital cameras. The lens incorporates a rear focus system eliminating front lens rotation. The focusing ring does not rotate during autofocus yet provides adequate focusing torque of the focusing ring during manual focusing of the lens. The lens materials used in this new lens are lead and arsenic free ecological glass.

UPC: 085126411459
Performance
Focal Length 20mm
Aperture Maximum: f/1.8
Minimum: f/22
Camera Mount Type Pentax K
Format Compatibility 35mm Film / Full-Frame Digital Sensor
Pentax Digital (APS-C)
Angle of View 94.5°
Minimum Focus Distance 7.9" (20.07 cm)
Magnification 0.25x
Maximum Reproduction Ratio 1:4
Elements/Groups 13/11
Diaphragm Blades 9
Features
Image Stabilization No
Autofocus Yes
Tripod Collar No
Physical
Filter Thread 82 mm
Dimensions (DxL) Approx. 3.5 x 3.4" (8.89 x 8.64 cm)
Weight 1.14 lb (520 g)
Packaging Info
Box Dimensions (LxWxH) 5.5 x 5.5 x 5.5"
Sigma Super Wide Angle 20mm f/1.8 EX Aspherical DG DF RF Autofocus Lens for Pentax AF
  • Front & Rear Caps
  • Lens Hood
  • Case
  • Limited 1-Year North and South America Warranty Against Manufacturing and Workmanship Defects.
  • Limited 3-Year U.S.A. Extended Warranty Extension Against Manufacturing and Workmanship Defects.
  • REVIEW SNAPSHOT®

    by PowerReviews
    SigmaSuper W/A 20mm f/1.8 EX Aspherical DG DF RF AF Lens
     
    4.6

    (based on 5 reviews)

    Ratings Distribution

    • 5 Stars

       

      (4)

    • 4 Stars

       

      (0)

    • 3 Stars

       

      (1)

    • 2 Stars

       

      (0)

    • 1 Stars

       

      (0)

    100%

    of respondents would recommend this to a friend.

    Pros

    • Consistent output (3)
    • Durable (3)

    Cons

    No Cons

    Best Uses

    • Low light (4)
    • Night photography (4)
      • Was this a gift?:
      • No (4)

    Reviewed by 5 customers

    Sort by

    Displaying reviews 1-5

    Back to top

    (0 of 2 customers found this review helpful)

     
    3.0

    Fast and Wide

    By Rob the Pentax shooter

    from Jersey City, NJ

    About Me Photo Enthusiast

    See all my reviews

    Verified Buyer

    Pros

    • Good in low light
    • Rugged
    • Super wide

    Cons

    • Heavy

    Best Uses

    • Close ups in a crowd
    • Indoors/Low Light
    • Macro Photography
    • Night Photography

    Comments about Sigma Super W/A 20mm f/1.8 EX Aspherical DG DF RF AF Lens:

    I have used this lens for some great razor sharp night shots, and good close ups in a crowd and it is pretty decent at up close macro like photos (this is not a macro lens but lets you focus pretty close to subject with a very wide angle perspective). I carry this lens and my 35 prime and for some events or larger venues my 85 prime. With this lens you get a very good wide angle perspective so it is great for a close up with the rest of what is going on in the background. Nice bokeh

    • Was this a gift?:
    • No

    Share this review

     
    5.0

    Premium lens

    By Jansune

    from Lund, Sweden

    About Me Photo Enthusiast

    Verified Buyer

    Pros

    • Consistent Output
    • Durable
    • Nice Bokeh

    Cons

    • Slow Focus

    Best Uses

    • Indoors/Low Light
    • Night Photography
    • Weddings/Events

    Comments about Sigma Super W/A 20mm f/1.8 EX Aspherical DG DF RF AF Lens:

    Excelent lens for outdoor in dawn and dusk. Or for people at parties or other social events.

    Sharp and bright! A little slow in autofocusing.

    • Was this a gift?:
    • No

    Share this review

     
    5.0

    Grat Lens, Great Quality.

    By B.Sweat

    from Chico, Ca

    About Me Pro Photographer

    Verified Reviewer

    Pros

    • Consistent Output
    • Depth of Field
    • Durable
    • Easily Interchangeable
    • Fast / accurate auto-focus
    • Rugged
    • Strong Construction

    Cons

    • 82mm Filter Size
    • Heavy

    Best Uses

    • Indoors/Low Light
    • Landscape/Scenery
    • Macro Photography
    • Night Photography
    • Sports/Action
    • Video
    • Weddings/Events
    • Wildlife Photos

    Comments about Sigma Super W/A 20mm f/1.8 EX Aspherical DG DF RF AF Lens:

    I read many reviews of this lens before purchasing. To be honest, I was skeptical of how sharp images would be between f1.8 - f2.7 after reading several reviews that images weren't coming out sharp enough.

    After receiving this lens and playing with it at low aperture, it's an extremely sharp lens. However there is a little distortion around the edges, but your focus always remains as sharp as it gets. The distortion around the edges seems to go away around f4.0. The low aperture lets you get an amazing depth of field, especially shooting macro or with close ups. Overall, this lens is above what I expected. The 20mm is very universal, and I have been using it for video with my K7. One quirk about this lens that does bother me is that my Pentax K7 doesn't read the lens as an aperture of f1.8, it reads it as f1.7 which I think is an issue with the CMOS sensor. Besides this, this lens for exceeded my expectations, and would recommend it to anyone wanting a decent wide angle prime.

    • Was this a gift?:
    • No

    Share this review

    (1 of 1 customers found this review helpful)

     
    5.0

    Very good Image Quality!

    By Irak Perez

    from Mexico City

    About Me Pro Photographer

    Verified Reviewer

    Pros

    • Consistent Output
    • Durable
    • Easily Interchangeable
    • Firm rings
    • Strong Construction
    • Superb Image Quality

    Cons

    • 82mm Filter Size
    • Easy to scratch wo filter

    Best Uses

    • Architechture
    • Full body shots
    • Indoors/Low Light
    • Landscape/Scenery
    • Night Photography

    Comments about Sigma Super W/A 20mm f/1.8 EX Aspherical DG DF RF AF Lens:

    I'll start with the only con...

    82mm filters are so expensive.

    Now...The pros:

    1) Full compatibility with ASP-c and with 35mm full format. Checked this with K7 & K20d as well as the PZ-1p & MZ-S

    2)Highly recomemded for any wide angle needs, but specially f1.8 will give you way more light than the zooms in that range

    3) Consistent image quality at all apertures, withe the reserve of some purple fringe in the corners at f1.8 noticeable on very dark subjects against very bright whites like overcasty sky, as well as some softness also in the corners up to 2.8, from 2.8 to 16 I have no complain.

    4) no noticeable distortion.

    5) well build for a plastic lens

    6) Fast accurate focus in good ligh (not so good in plain uncontrasted surfaces in lo light)

    7) ergonomic well thought auto/manual focus shift

    8)The easiest lens hood to install (that I have tried)

    PUT A UV OR CLEAR FILTER, IT IS VERY EASY TO SCRATCH THE FRONT ELEMENT

    Possible question: Why to keep this one while having an invaluable and superior in image quality Zeiss Distagon T* 3,5/18?

    Answer: The f1.8 from this sigma's baby

    • Was this a gift?:
    • No

    Share this review

    (6 of 6 customers found this review helpful)

     
    5.0

    Bright Primes Rule

    By Dan Johnson

    from Boston Massachusetts U.S.A.

    Comments about Sigma Super W/A 20mm f/1.8 EX Aspherical DG DF RF AF Lens:

    I love it for low light photography, indoors without a flash, and to isolate the subject from the background. Both the autofocus and manual focus work great and the image is fine. I like telephoto zooms but for wide angle I prefer bright primes, and this is becoming my favorite. Even if I didnt have a 35mm film SLR I would buy this because it seems like everyone is coming out with a Digital SLR that uses a Full Frame CCD or CMOS which have no lens factor (a 20mm will work like a 20mm instead of a 30mm)

    Expertise: Advanced Amateur Shutterbug for 30 Years

    Problems Encountered: You are limited to 1 normal size filter (for 35mm film or a full frame CCD cameras) So it's a good idea to buy a thin polarizing filter, however with a 1.5 or 1.6 lens factor you should be able to use 2 filters at the same time or a full size polarizing filter

    Previous Equivalent Item Owned: Pentax A 50mm f:1.2 Lens

    Items I Recommend: Sigma Thin Polarizing Filter & Sigma Thin UV Filter

    Share this review

    Filters & Filter Kits

    See more
    Hoya - 82mm UV Haze NXT HMC Filter
    • You Pay: $68.85
     
    Tiffen - 82mm Digital Essentials Filter Kit
    • You Pay: $184.31
     

    Hoods & Covers

    Flex Lens Shade - Flex Lens Shade
    • You Pay: $39.95
     

    Cases & Wraps

    See more
    Pearstone - Onyx 50 Lens Case
    • You Pay: $16.95
     
    View all Accessories
    See any errors on this page? Let us know.

    Close

    Close

    Close