Table of Contents
Pentax SMC 17mm f/4 Fish-Eye
Summary
The SMC Pentax 17mm f/4 Fish-Eye is a compact, manual-focus ultra-wide lens introduced in 1975 and produced until 1985, designed for full-frame K-mount film cameras. It delivers a 180° diagonal field of view while filling the frame rather than producing a circular image. With an 11-element/7-group optical design, Super Multi-Coating (SMC), and a 6-blade automatic diaphragm, it was Pentax’s only K-series diagonal fisheye prime, later succeeded by the A 16mm F2.8. The lens has no front filter thread due to its bulbous front element, but includes a built-in rotating turret with four internal filters: Skylight, UV, Yellow, and Orange—a feature especially useful for black-and-white film photography. It also accepts rear-mounted gelatin filters. The minimum focus distance is 20cm, offering 0.1× magnification, and the lens weighs just 234g, measuring 64.5 × 34mm—remarkably small for a full-frame fisheye.
Tech Specs
| Manufacturer | Pentax |
| Series | K Series Fish-Eye |
| Model | SMC |
| Focal Length | 17mm |
| Max Aperture | f/4 |
| Min Aperture | f/22 |
| Format | Full-Frame |
| Image Circle | - |
| Minimum Focus | 20cm |
| Focus Rotation | ° |
| Iris Blades | 6 |
| Optical Design | 11/7 |
| Squeeze | none |
| Front Diameter | 64.5mm |
| Filter Thread | none |
| Focus/Zoom Rod | none |
| Native Mount | Pentax K |
| Data Protocol | none |
| Length | 34mm |
| Weight | 234g |
| Body Telescope | - |
| Body Material | - |
| Focus Drive | - |
| Iris Drive | - |
| Zoom Drive | - |
History
Country of Origin:
Release Date: 1975
Launch Price:
Design Revisions: