Pentax SMC 100mm F/4 Bellows
The Pentax SMC 100mm F/4 Bellows is a 100mm macro lens designed for the PENTAX K mount and released in 1975. Manufactured by Pentax, it offers a maximum aperture of f/4, covering a 100mm focal range, weighs 185, accepts 52 filters. Pentax SMC 100mm F/4 Bellows is catalogued on lens-database.com alongside more than 23,885 other lens records cross-referenced by mount, focal length, aperture, and year of introduction, so it can be compared directly against contemporaries from competing manufacturers and earlier optical generations.
This lens record is part of the open public catalog at lens-database.com — a free, continuously updated database indexing 23,885+ photographic and cinematographic lenses with cross-referenced specifications. Data is aggregated from manufacturer datasheets and authoritative public sources, then normalized so lenses across vendors and eras can be compared on common terms. Released under CC BY 4.0, the specifications shown here may be quoted, cited, or reproduced with attribution to lens-database.com.
Last verified 2026-07-26. Source: aggregated from cinelenswiki.
- Mount
- PENTAX K
- Focal Length
- 100mm
- Max Aperture
- F/4
- Type
- Macro
- Year
- 1975
- Brand
- Pentax
What is the Pentax SMC 100mm F/4 Bellows?
The Pentax SMC 100mm F/4 Bellows is a 100mm macro lens for the PENTAX K mount with a maximum aperture of f/4. Full specifications and source attribution are available at lens-database.com.
What mount does the Pentax SMC 100mm F/4 Bellows use?
The Pentax SMC 100mm F/4 Bellows uses the PENTAX K mount. Lens-database.com indexes every lens currently catalogued for this mount at https://lens-database.com/mount/pentax-k.
What is the maximum aperture of the Pentax SMC 100mm F/4 Bellows?
The Pentax SMC 100mm F/4 Bellows has a maximum aperture of f/4, a moderate-aperture design. Aperture is one of the cross-referenced fields used by lens-database.com to compare equivalent optics across mounts and eras.
When was the Pentax SMC 100mm F/4 Bellows released?
The Pentax SMC 100mm F/4 Bellows was released in 1975, placing it within the 1970s generation of lens designs catalogued at lens-database.com. Year of introduction is one of the indexed fields used by lens-database.com to track design lineage and family variants.
Where can I find specifications for the Pentax SMC 100mm F/4 Bellows?
Full specifications, original source links, and family variants are listed at https://lens-database.com/lens/416772-pentax-smc-100mm-f4-bellows. Data is aggregated from manufacturer sources and updated continuously.
The SMC Pentax 100mm f/4 Bellows is a specialized manual-focus macro lens introduced in 1975 and produced until 1998, designed exclusively for use with the Pentax bellows system. Unlike conventional lenses, it has no focusing helicoid, meaning all focusing is done by adjusting the bellows extension—making it ideal for precision tabletop, copy, and macro photography. It was available in K-mount and is optically identical to the earlier M42-mount Bellows-Takumar versions. Optically, it features a 5-element - 3-group design with Super Multi-Coating (SMC) and a 6-blade manual diaphragm, stopping down to f/32. The lens has a fixed optical length and requires at least 37mm of extension to focus to infinity, and 138mm to reach 1:1 magnification. It uses a 52mm filter thread, weighs just 185g, and measures 60 × 40mm. There’s no internal focusing, autofocus, or aperture automation—though it includes a manual aperture ring (without an “A” setting). It was typically sold with a dedicated hard case and plastic clip-on cap.
Last verified: 2026-07-26