Quick answer
The Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR is a ultra-wide to standard zoom lens covering 20-40mm at f/2.8 for the Pentax K mount. Its bright maximum aperture handles indoor and evening light reasonably well.
About this lens
The Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR is an APS-C wide-angle zoom lens covering 20-40mm at f/2.8-4 for Pentax K mount cameras, with weather-resistant construction and extra-low dispersion glass. A compact, metal-bodied Limited-series prime for Pentax K-mount cameras.
Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR specifications
What can you shoot with the Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR?
At 20-40mm this is a ultra-wide to standard zoom, which typically suits:
- Landscapes and big skies
- Architecture and interiors
- Astrophotography and night skies
- Landscapes and cityscapes
- Street and travel photography
Its bright maximum aperture handles indoor and evening light reasonably well.
Full-frame equivalent and field of view
Calculated from the focal length and crop factor. Not measured.
| Sensor | Crop | Equivalent | Horizontal FOV | Diagonal FOV |
|---|---|---|---|---|
| Full frame | 1.0x | 20–40mm | 48.5–84° | 56.8–94.5° |
| APS-C | 1.5x | 30–60mm | 33.4–61.9° | 39.7–71.6° |
Frequently asked questions
What mount does the Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR use?
It uses the Pentax K mount, so it fits Pentax K cameras directly.
What is the focal length of the Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR?
It zooms across 20-40mm with a maximum aperture of f/2.8. That makes it a ultra-wide to standard lens.
Is the Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR a prime or a zoom lens?
It is a zoom lens covering 20-40mm, so you can reframe without moving. Its maximum aperture is f/2.8.
What is the Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR equivalent on a crop sensor?
On APS-C (1.5x crop) it frames like 30–60mm on full frame, with a 33.4–61.9° horizontal and 39.7–71.6° diagonal field of view. These figures are calculated from the focal length and crop factor.
Which cameras does the Pentax HD Pentax-DA 20-40mm f/2.8-4 ED Limited DC WR fit?
Any Pentax K-mount camera, including Pentax K-1, Pentax K-3, Pentax K-3 II, Pentax K-3 Mark III, and Pentax K-30 and 15 more.
Alternatives for Pentax K from other brands
All Pentax K lensesSame mount, overlapping focal range, closest maximum aperture first.
More Pentax lenses for Pentax K
All Pentax lensesOther 20-40mm lenses
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