Pentax DA 20-40mm F2.8-4 ED DC WR is a Variable aperture Auto Focus (AF)
Standard Zoom lens with APS-C / DX max sensor coverage, and it is designed to be used with
KAF3 Mount cameras.
What type of photography is the Pentax DA 20-40mm F2.8-4 ED DC WR lens good for?
The choice of photography type for which you intend to use the Pentax DA 20-40mm F2.8-4 ED DC WR is a crucial decision factor. Below, we have assessed its suitability for various photography scenarios:
Reasons to Buy the HD Pentax-DA 20-40mm F2.8-4 ED Limited DC WR Lens
Here we've included a summary of the advantages and disadvantages of the HD Pentax-DA 20-40mm F2.8-4 ED Limited DC WR lens in a list form to assist you in determining whether it offers the features you need.
| Weather-sealed |
| Autofocus |
| Distance Scale |
| DoF(Depth of Field) Scale |
| Hood supplied |
| Full-time Manual Focusing |
| Fast Aperture at Wide end |
| Fast Aperture at Tele end |
| 9 Diaphragm Blades for Smooth Bokeh |
| Min focus distance of 0.28m / 11.0 inch |
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| Lens Extends while zooming |
| Variable Aperture |
Lens Mount
Pentax DA 20-40mm F2.8-4 ED DC WR is compatible with cameras that have a Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are , and .
Size, Weight and Filter Thread
The size and weight are crucial factors to consider when searching for your next lens. Pentax DA 20-40mm F2.8-4 ED DC WR has a maximum diameter of 71mm and a total length of 69mm when not extended. It weighs 283g / 10.0 oz.
Pentax DA 20-40mm F2.8-4 ED DC WR has a filter thread of 55mm. Below are links to the filters that we recommend you to consider for your Pentax DA 20-40mm F2.8-4 ED DC WR:
You can also check All Pentax KAF Mount Lenses with 55mm Filter Thread Size to find the matching lenses.
Focal Range
Pentax DA 20-40mm F2.8-4 ED DC WR has a focal range of 20-40mm and 2.0X zoom ratio which has a 35mm equivalent focal range of 30-60mm when used on a APS-C / DX format camera.
Weather Sealings
The Pentax DA 20-40mm F2.8-4 ED DC WR is a weather-sealed lens, which provides extra protection to prevent water and dust get inside the lens and camera body under light rain, snow and wind. In order to have effective protection, you have to pair the Pentax DA 20-40mm F2.8-4 ED DC WR with a weather-sealed camera body such as the , and .
Optical Image Stabilization
Pentax DA 20-40mm F2.8-4 ED DC WR doesn't have an optical image stabilization system so the only option to stabilize the image taken with this lens is to mount on a camera body with IBIS (sensor based In-body image stabilization).
Zoom Method
Pentax DA 20-40mm F2.8-4 ED DC WR features Rotary (extending) zoom method where the length of the lens changes as you zoom in or out. This makes it possible to design the lens with a smaller minimum length ( generally when it is zoomed out) compared to internal zoom lenses. The disadvantages of this design are being harder to seal against dust and moisture, weight balance shifting while zooming and zoom creep in certain lenses.
Maximum Magnification Ratio
Pentax DA 20-40mm F2.8-4 ED DC WR has a Max Magnification Ratio of 0.2x with a minimum focusing distance of 0.28m.
Below are the 3 Standard Zoom type Pentax KAF3 mount lens alternatives with highest max magnification ratios:
Aperture
Pentax DA 20-40mm F2.8-4 ED DC WR is a variable aperture lens with a max aperture of f2.8 and a minimum aperture of f22 at 20mm, and a max aperture of f4 and minimum aperture of f32 at 40mm .
| Focal Length |
Max Aperture |
Min Aperture |
|
20mm
|
F2.8 |
F22 |
|
40mm
|
F4 |
F32 |
Optical Formula
Pentax DA 20-40mm F2.8-4 ED DC WR's optical formula consists of 9 elements in 8 groups . The following special elements are used in this design:
- 1 ED glass element
- 1 SLD glass element
- HD coating
Lens Hood
Pentax DA 20-40mm F2.8-4 ED DC WR comes with a removable lens hood which is handy to reduce lens flare and glare in your photos. The model number of the hood is MH-RA55.
Body Colour
Pentax DA 20-40mm F2.8-4 ED DC WR is available in Black and silver color.
Popular Comparisons of Pentax DA 20-40mm F2.8-4 ED DC WR
Here are the 8 most popular comparisons of the Pentax DA 20-40mm F2.8-4 ED DC WR amongst Camera Decision readers.
Top Alternatives of Pentax DA 20-40mm F2.8-4 ED DC WR Lens
In addition, it would be interesting to check which lenses from other mounts are most commonly compared with the HD Pentax-DA 20-40mm F2.8-4 ED Limited DC WR.
Top Alternatives of Pentax DA 20-40mm F2.8-4 ED DC WR in Other Lens Mounts
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