Pentax DA 40mm f/2.8 XS Slim Design Lens
The Pentax 40mm f/2.8 XS is a 40mm f/2.8 lens designed for Pentax K mount cameras. Used copies start from $145.86 on GearFocus, with buyer protection on every purchase.
Pentax DA 40mm f/2.8 XS Slim Design Lens
Used Pentax 40mm f/2.8 XS Listings on GearFocus
Lens Overview — Pentax 40mm f/2.8 XS
Key Features — Pentax 40mm f/2.8 XS
45g Ultralight Body: At just 45 grams, this is one of the lightest autofocus lenses available for any system, making it ideal for minimal-kit shooting.
40mm f/2.8 Prime: The 40mm focal length on APS-C produces a natural, standard field of view roughly equivalent to 61mm in full-frame terms.
Pancake-Style Profile: The XS designation refers to its exceptionally slim physical depth, allowing compatible cameras to remain nearly pocket-sized.
Pentax K-Mount Compatibility: Designed for Pentax APS-C bodies, with particular fit and aesthetic consideration given to the mirrorless Pentax K-01.
Autofocus Support: Built-in autofocus motor allows hands-free focus acquisition, with manual focus override also available for precise control.
27mm Filter Thread: The unusually small 27mm filter thread reflects the lens's compact design, though it does require specific filter sizes that are less commonly stocked.
Lens Specifications — Pentax 40mm f/2.8 XS
| Spec | Detail |
|---|---|
| Use Cases | Travel |
| Lens Type | Pancake |
| Format | APS-C |
| Zoom/Prime | Prime |
| Focal Length | 40mm |
| Maximum Aperture | f/2.8 |
| Camera System | Pentax K-mount digital cameras (APS-C), designed for Pentax K-01 and compatible K-mount bodies |
| Lens Mount | Pentax K |
| Autofocus | Yes |
| Focus Type | Auto, Manual |
| Image Stabilization | None |
| Filter Thread | 27mm |
Description — Pentax 40mm f/2.8 XS
The Pentax DA 40mm f/2.8 XS is a prime lens with a 40mm fixed focal length, purpose-built for the Pentax K-mount system and designed for use with APS-C format digital cameras. Its standout physical characteristic is its remarkable 45g weight, making it among the lightest options available for K-mount shooters and an ideal companion for everyday carry. The f/2.8 maximum aperture gives photographers meaningful control over depth of field and accommodates a range of shooting conditions.
Accepting filters via its 27mm thread, the lens maintains a slim, compact profile consistent with its XS designation. Autofocus and manual focus are both supported, providing shooting versatility. There is no image stabilization on board, so handheld technique matters.
Compatibility is focused on Pentax K-mount APS-C bodies, with the Pentax K-01 specifically noted as a key pairing. For Pentax shooters looking for a lightweight, standard-perspective prime, the DA 40mm f/2.8 XS delivers a clear and focused feature set.
Pros — Pentax 40mm f/2.8 XS
- ✓Exceptionally lightweight at just 45g, making it one of the most portable options for Pentax K-mount shooters
- ✓Maximum aperture of f/2.8 provides useful depth-of-field control for a standard prime lens
- ✓Supports both autofocus and manual focus, offering shooting flexibility
Cons — Pentax 40mm f/2.8 XS
- ✗No image stabilization, which may limit handheld shooting in challenging light
- ✗Compatibility is limited to Pentax K-mount APS-C bodies, reducing versatility for multi-system shooters
- ✗The 27mm filter thread is uncommon, making filter selection more limited compared to standard sizes
Videos — Pentax 40mm f/2.8 XS
WORLD'S SLIMMEST LENS — Robin Wong