HD PENTAX-DA 20-40mmF2.8-4ED Limited DC WR is listed for Pentax K with Unknown coverage. Its verified front filter size is Ø55 mm. Ricoh lists this in its K-mount lens catalog; the electronic subtype is not stated on this page. Check the exact body support table for electronic functions.
As an Amazon Associate I earn from qualifying purchases.
Verified specifications
| Field | Value |
|---|---|
| Mount | Pentax K |
| Mount subtype | Unknown |
| Image format | Unknown |
| Front filter thread | Ø55 mm |
| Model ID | pentax-hdpentax-da-20-40 |
| Optical construction | 9 elements / 8 groups |
| Closest focus | 0.28m |
| Maximum magnification | 0.20x |
| Minimum aperture | F22-32 |
| Aperture blades | 9 |
The maker also lists 9 elements / 8 groups for the optical design and a closest-focus specification of 0.28m. These are lens specifications, not a guarantee of performance on every body or in every shooting mode.
Compare camera lenses listings
Compare the exact model code and rear mount in each listing. Amazon results may contain another mount or generation; the search is not a compatibility verdict.
(paid link)
Search camera lenses on AmazonChoosing a camera
Look for the Pentax K designation on the camera specification, then verify the exact model code and mount variant against its support page. A physical mount match is a starting point; still AF, movie AF, crop behavior, stabilization and firmware need separate checks.
Choosing a filter
A circular screw-in filter with a matching documented thread size is only a mechanical candidate. Magnetic filters, wide frames and stacked rings need separate system and vignetting checks. When no front thread is specified, do not buy a size from the focal length or barrel diameter.
Keep exploring
Official sources and scope
Checked for this reference on October 30, 2026. Product firmware and support lists can change; inspect the current maker page for your exact revision.