Table of Contents
Pentax-M SMC 28mm f/3.5
Summary
The SMC Pentax-M 28mm f/3.5 is a compact, manual-focus wide-angle prime lens for Pentax K-mount 35mm and full-frame digital SLRs, produced from 1977 to 1985. It features a 6-element/6-group optical design, a 5-blade automatic diaphragm, and Pentax’s Super Multi-Coating (SMC) for improved contrast and flare resistance. As the slower of the two M-series 28mm variants, it prioritizes sharpness and portability over speed. With a 75° diagonal field of view on full-frame and a minimum focus distance of 0.3m, it’s well-suited for landscapes, architecture, and general-purpose shooting. The lens uses a 49mm filter thread, weighs just 180g, and measures 63 × 31.5mm, making it one of the smallest wide-angle primes in the Pentax lineup. It lacks an “A” setting on the aperture ring but is fully compatible with manual and aperture-priority modes on Pentax DSLRs.
Tech Specs
| Manufacturer | Pentax |
| Series | M Series Prime |
| Model | SMC |
| Focal Length | 28mm |
| Max Aperture | f/3.5 |
| Min Aperture | f/22 |
| Format | Full-Frame |
| Image Circle | - |
| Minimum Focus | 30cm |
| Focus Rotation | ° |
| Iris Blades | 5 |
| Optical Design | 6/6 |
| Squeeze | none |
| Front Diameter | 63mm |
| Filter Thread | 49mm |
| Focus/Zoom Rod | none |
| Native Mount | Pentax K |
| Data Protocol | none |
| Length | 31.5mm |
| Weight | 180g |
| Body Telescope | - |
| Body Material | - |
| Focus Drive | - |
| Iris Drive | - |
| Zoom Drive | - |
History
Country of Origin:
Release Date: 1977
Launch Price:
Design Revisions:
Service
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Service Manual: (Insert link to manual here)
Full CLA: TBD hrs.
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Cine-Mod
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Focus Ring O.D.: -
Zoom Ring O.D.: -
Iris Ring O.D.: -
De-click Y/N: -
Additional Notes:
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