Table of Contents
Pentax SMC 105mm f/2.8
Summary
The SMC Pentax 105mm f/2.8 is a rare short telephoto prime introduced in 1975 and produced until 1977, designed for full-frame K-mount film cameras. It’s the only 105mm lens Pentax ever made in the K bayonet mount, making it a unique entry in the K-series lineup—positioned between the more common 100mm and 135mm focal lengths. It features a 5-element - 4-group optical design, Super Multi-Coating (SMC), and a 6-blade automatic diaphragm. The lens stops down to f/32, focuses as close as 1.2 meters, and delivers 0.11× magnification. It uses a 52mm filter thread, weighs 294g, and measures 63 × 63mm. It includes a PH-R52 clip-on hood, plastic cap, and was often sold with a dedicated hard case. There’s no “A” setting on the aperture ring, so it’s best used in manual or aperture-priority modes.
Tech Specs
| Manufacturer | Pentax |
| Series | K Series Prime |
| Model | SMC |
| Focal Length | 105mm |
| Max Aperture | f/2.8 |
| Min Aperture | f/32 |
| Format | Full-Frame |
| Image Circle | - |
| Minimum Focus | 120cm |
| Focus Rotation | ° |
| Iris Blades | 6 |
| Optical Design | 5/4 |
| Squeeze | none |
| Front Diameter | 63mm |
| Filter Thread | 52mm |
| Focus/Zoom Rod | none |
| Native Mount | Pentax K |
| Data Protocol | none |
| Length | 63mm |
| Weight | 294g |
| Body Telescope | - |
| Body Material | - |
| Focus Drive | - |
| Iris Drive | - |
| Zoom Drive | - |
History
Country of Origin:
Release Date: 1975
Launch Price:
Design Revisions: