Pentax-DA 50-200mm F4-5.6 WR Review

Specifications

Specifications, per the Pentax website

Physical
  • Dimensions (diameter x length): 2.7 x 3.1" (69.0 x 79.5mm) *
  • Weight: 10.1 oz (285g) without hood
  • Filter Size: 49mm
  • Aperture Blades: 6
  • Optical Construction: 11 elements in 10 groups
  • Mount Type: K Mount
Mechanical
  • Maximum Aperture: F4-5.6
  • Minimum Aperture: F22-32
  • Diagonal Angle of View: 32-8.1 Degrees
  • Minimum Focus Distance: 43.2 inches **
  • Maximum Magnification: 0.24x
Accessories
  • Lens Hood: PH-RBD 49mm (included)
  • Hood Weight: 40g (1.41oz)
  • Optional Case: S80-120
* Without hood and at 18mm zoom position
** It may actually focus a little closer than this; see the review for details

Minimum Focus Distance

This statistic may not seem important as this is not a macro lens, however it is a such a versatile lens that it is quite likely a user will be caught with only this lens and the need to get up close to something. Therefore, lets take a look. Pentax list the minimum focus distance for this lens as 43.2 inches, however tests seem to show it focusing a bit closer. The K200D used in the test does not have a film plane indicator on the body and if Pentax are calculating from this location, it could not be easily duplicated in the lab (reviewers living room). Therefore, the working distance (the distance from the end of the lens to the subject) was measured. The results are shown in the images below.

Minimum focus distance at 50mm and at 200mm

At both 50mm and 200mm, the minimum focus distance seems to be about 35 inches. Using a 50mm focal length to test, the Pentax measurement seems a bit long. The K200D with the DA 50-200mm WR lens, focused at the extreme minimum which adds 1/2 inch to the overall length, totals 6.5 inches. This length added to the 35 inch test result gets us only 41.5 inches and would require the film plane indicator to be around two inches behind the camera. Pentax were contacted regarding this and responded that they believe their tests to be accurate though they did not wish to elaborate on the technique used. More than likely it is 43.2 and the Pentax specs are correct, but users should be able to assume a minimum working distance of 35 inches.


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