Pentax F 17-28mm lens

The smc Pentax-F 17–28mm Fish-eye f/3.5–4.5 is the first fisheye zoom lens, manufactured by Pentax for single-lens reflex cameras (SLRs) with a K lens mount. At its widest setting of 17mm, it affords a 180° diagonal angle of view images for all K-mount full-frame SLR cameras; at 28mm, the diagonal angle of view is reduced to 90° on the diagonal. Typical fisheye barrel distortion is evident at all focal lengths. A successor model, the Pentax DA 10-17mm lens, was introduced with the same view angles and closer focusing capability for APS-C cameras in 2006.

smc PENTAX-F FISH-EYE ZOOM 17mm–28mm F3.5-4.5
MakerPentax
Technical data
TypeZoom
Focus drivescrew
Focal length17–28mm
Crop factor1
Aperture (max/min)f/3.5-4.5
Close focus distance0.45 m (1 ft 6 in)[1]
Max. magnification0.07[1]
Construction9 elements in 7 groups
Features
Lens-based stabilization No
Macro capable No
Unique featuresFisheye
ApplicationSpecial Effect
Physical
Max. length61 mm (2.4 in)[1]
Diameter65 mm (2.6 in)[1]
Weight255 g (9.0 oz)[1]
Filter diameterN/A
Accessories
Lens hoodbuilt-in
Angle of view
Diagonal180°–90°[1]

History and design

The lens was designed by Jun Hirakawa and a patent was applied for the design in 1994, granted in 1998.[2]

Longtime photography writer Herbert Keppler was a noted fan of the lens, as its unique zoom capabilities allow the user to minimize the appearance of barrel distortion.[3] Keppler wrote in an informal review "You don't use this lens to make your best girl- or boyfriend look pretty or handsome, but it does produce some fantastically fascinating effects. [...] there still are many moments when its coverage just fits the coverage of my mind."[4]

  • Rogers Centre, 17mm (2016).
  • Inside Rogers Centre, 28mm (2016).
  • Distortion minimized by subject matter and placement, 28mm (2016).
  • Lines not passing through center are distorted, 17mm (2016).
  • Distortion at full-frame view, 17mm (2016).
gollark: Better idea: dig out all roads to bedrock, fill trenches with lava.
gollark: It will produce... excitement...
gollark: Break into everyone's house and install potatos.
gollark: And is not 2/2.5m away from.the stuff.
gollark: The point you have marked is just some weird point on a line between them.

References
  1. "F-ZOOM Lenses". Pentax. 1999. Archived from the original on 24 August 1999. Retrieved 6 November 2017.
  2. US patent 5724193A, Hirakawa, Jun, "Super wide angle zoom lens", published 1998-03-03, issued 1998-03-03, assigned to Pentax Corp
  3. Keppler, Herbert (August 2006). "SLR: World-Class Glass". Popular Photography. Retrieved 5 November 2017.
  4. Keppler, Herbert (September 1996). "17mm fisheye to 28mm wide-angle zoom: What a wacky idea, or is it?". Popular Photography. Retrieved 5 November 2017.

Specifications
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