Pentax 135mm f/1.8 SMC Lens
The Pentax 135mm f/1.8 is a 135mm f/1.8 lens designed for Pentax K mount cameras. Check GearFocus for current availability, with buyer protection on every purchase.
Pentax 135mm f/1.8 SMC Lens
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Lens Overview — Pentax 135mm f/1.8
Key Features — Pentax 135mm f/1.8
135mm f/1.8 Prime: A fixed 135mm focal length with an f/1.8 maximum aperture, making this one of the fastest lenses available at this focal length for significant background separation and low-light capability.
Full-Frame Coverage: Designed to cover full-frame SLR sensors with no vignetting, making it fully compatible with both film and digital full-frame Pentax bodies.
Pentax K Mount: Native Pentax K mount is widely supported by third-party adapters, allowing this lens to be used on a range of modern mirrorless systems beyond the Pentax ecosystem.
Manual Focus Only: Operates entirely via manual focus, suited to photographers who prefer deliberate, hands-on control in portrait, still life, or creative telephoto work.
SMC Coating: Pentax's Super Multi-Coating reduces flare and ghosting, helping to maintain contrast and color fidelity when shooting toward light sources.
77mm Filter Thread: The 77mm front filter thread is a professional standard size, compatible with a wide range of polarizers, ND filters, and other accessories.
Lens Specifications — Pentax 135mm f/1.8
| Spec | Detail |
|---|---|
| Use Cases | Portrait, Creative Effects |
| Lens Type | Prime |
| Format | Full Frame |
| Zoom/Prime | Prime |
| Focal Length | 135mm |
| Maximum Aperture | f/1.8 |
| Camera System | SLR |
| Lens Mount | Pentax K |
| Autofocus | No |
| Focus Type | Manual |
| Image Stabilization | None |
| Filter Thread | 77mm |
Description — Pentax 135mm f/1.8
The Pentax 135mm f/1.8 SMC is a prime telephoto lens with a Pentax K mount, built to cover full-frame SLR camera systems. Its standout characteristic is the f/1.8 maximum aperture, which is exceptionally fast for a 135mm focal length and opens up creative possibilities with shallow depth of field and performance in available light. This is a manual focus only lens, meaning the photographer controls focus entirely by hand — a workflow that suits deliberate, considered shooting styles.
The lens features a 77mm filter thread, making it compatible with a broad range of professional-grade circular filters. At 930g, it has a solid, substantial feel. There is no image stabilization, so steady handholding technique or tripod use is recommended at this focal length.
Whether used natively on Pentax K-mount bodies or adapted to a modern mirrorless system, the 135mm f/1.8 SMC offers a fixed focal length with a wide-open aperture that gives photographers precise, intentional control over their image.
Pros — Pentax 135mm f/1.8
- ✓Very fast maximum aperture of f/1.8 at 135mm enables significant background separation and low-light shooting
- ✓Full-frame coverage ensures compatibility with full-frame SLR bodies without vignetting concerns
- ✓77mm filter thread accommodates a wide range of professional filters
Cons — Pentax 135mm f/1.8
- ✗Manual focus only — no autofocus support, which limits usability for action or fast-moving subjects
- ✗At 930g, the lens is quite heavy and may add noticeable weight to a shooting kit
- ✗No image stabilization, which combined with the 135mm focal length requires careful technique to avoid camera shake
Videos — Pentax 135mm f/1.8
Fuji X-T2 + SMC Pentax-M 135mm f3.5 Vintage Lens — Damian Brown