Table of Contents
Pentax SMC 135mm f/2.5
Summary
The SMC Pentax 135mm f/2.5 is a fast, manual-focus telephoto prime lens for Pentax K-mount 35mm and full-frame digital SLRs, produced from 1975 to 1985. It features a 6-element/6-group optical design, an 8-blade automatic diaphragm, and Pentax’s Super Multi-Coating (SMC) for excellent contrast, color fidelity, and flare resistance. With a bright f/2.5 aperture and a minimum focus distance of 1.5m, it’s ideal for portraits, nature, and compressed-perspective scenes with shallow depth-of-field. The lens uses a 58mm filter thread, weighs 500g, and measures 68 × 86mm in a robust all-metal barrel. It delivers excellent center sharpness and rich color rendering, especially from f/4 to f/8, with a smooth, natural bokeh that makes it a favorite for portraiture. While it lacks a built-in hood, it was originally supplied with a clip-on PH-R58 hood and hard case.
Tech Specs
| Manufacturer | Pentax |
| Series | K Series Prime |
| Model | SMC |
| Focal Length | 135mm |
| Max Aperture | f/2.5 |
| Min Aperture | f/32 |
| Format | Full-Frame |
| Image Circle | - |
| Minimum Focus | 150cm |
| Focus Rotation | ° |
| Iris Blades | 8 |
| Optical Design | 6/6 |
| Squeeze | none |
| Front Diameter | 68mm |
| Filter Thread | 58mm |
| Focus/Zoom Rod | none |
| Native Mount | Pentax K |
| Data Protocol | none |
| Length | 86mm |
| Weight | 500g |
| Body Telescope | - |
| Body Material | - |
| Focus Drive | - |
| Iris Drive | - |
| Zoom Drive | - |
History
Country of Origin:
Release Date: 1975
Launch Price:
Design Revisions: