smc PENTAX-D FA645 25mmF4AL[IF] SDM AW is listed for Pentax 645 with 645 medium format coverage. A front screw-in filter size is not established by the checked evidence, so no diameter is recommended. Ricoh lists this exact lens under its 645-mount catalog. Camera-specific electronic functions remain unassessed.
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Verified specifications
| Field | Value |
|---|---|
| Mount | Pentax 645 |
| Image format | 645 medium format |
| Front filter thread | Not specified in checked source |
| Model ID | pentax-645-smcpentax-dfa645-25 |
| Optical construction | 12 elements / 8 groups |
| Closest focus | 0.4m |
| Maximum magnification | 0.11x |
| Minimum aperture | F32 |
| Aperture blades | 9 |
The maker also lists 12 elements / 8 groups for the optical design and a closest-focus specification of 0.4m. These are lens specifications, not a guarantee of performance on every body or in every shooting mode.
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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.
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Search camera lenses on AmazonChoosing a camera
Look for the Pentax 645 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.
This model cannot enter the diameter calculator until a verified front thread or dedicated holder specification is available.
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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.