HD PENTAX-DA645 28-45mm f/4.5 ED AW SR Medium Format Lens
The Pentax 28-45mm f/4.5 ED AW SR is a 28–45mm f/4.5 lens designed for Pentax 645 mount cameras. Check GearFocus for current availability, with buyer protection on every purchase.
HD PENTAX-DA645 28-45mm f/4.5 ED AW SR Medium Format Lens
Get notified when one lists.
We'll text or email you the moment a HD PENTAX-DA645 28-45mm f/4.5 ED AW SR Medium Format Lens is listed on GearFocus.
Have a Pentax 28-45mm f/4.5 ED AW SR sitting in your bag?
You'd be the first listing for this model.
Serious buyers are already watching — list yours in minutes.
Available Now on GearFocus
Lens Overview — Pentax 28-45mm f/4.5 ED AW SR
Key Features — Pentax 28-45mm f/4.5 ED AW SR
28-45mm Wide-Angle Zoom: Covers a versatile wide-angle range suited to landscape, architectural, and environmental portrait work on medium format.
Pentax 645 Mount: Designed exclusively for the Pentax 645 medium format system, compatible with cameras like the Pentax 645Z and 645D.
Constant f/4.5 Aperture: Maximum aperture remains fixed across the full zoom range, ensuring consistent exposure and depth-of-field control at any focal length.
SR Optical Stabilization: Built-in optical image stabilization helps reduce the effects of camera shake during handheld shooting.
All-Weather Construction: AW-rated sealing protects against dust and moisture, making this lens practical for outdoor and on-location work in variable conditions.
Autofocus Support: Full autofocus capability with a manual focus override gives shooters flexibility across a range of shooting scenarios.
Lens Specifications — Pentax 28-45mm f/4.5 ED AW SR
| Spec | Detail |
|---|---|
| Use Cases | Studio |
| Lens Type | Zoom |
| Format | Medium Format |
| Zoom/Prime | Zoom |
| Focal Length | 28–45mm |
| Maximum Aperture | f/4.5 |
| Camera System | Medium Format |
| Lens Mount | Pentax 645 |
| Autofocus | Yes |
| Focus Type | Auto, Manual |
| Image Stabilization | Optical (OIS) |
| Filter Thread | 82mm |
Description — Pentax 28-45mm f/4.5 ED AW SR
The HD PENTAX-DA645 28-45mm f/4.5 ED AW SR is a wide-angle zoom lens purpose-built for the Pentax 645 medium format system. It spans a focal length range of 28mm to 45mm, making it well-suited for wide-angle applications including landscapes, interiors, and environmental work. The lens maintains a maximum aperture of f/4.5 throughout its zoom range, providing consistent light transmission and depth-of-field behavior.
Built-in optical image stabilization (SR) is a notable practical asset, helping photographers manage shake when shooting without a tripod. The AW (All Weather) construction means the lens is designed to hold up in outdoor conditions. At 1,470g, this is a substantial optic that reflects the build quality expected of a medium format zoom.
The 82mm filter thread accommodates a wide range of accessory filters. Both autofocus and manual focus are supported, giving users control over their focusing workflow depending on the demands of the scene.
Pros — Pentax 28-45mm f/4.5 ED AW SR
- ✓Optical image stabilization (SR) built into the lens for handheld shooting confidence
- ✓All-weather (AW) construction suits outdoor and unpredictable shooting environments
- ✓Versatile 28-45mm wide-angle zoom range on the Pentax 645 medium format system
Cons — Pentax 28-45mm f/4.5 ED AW SR
- ✗Maximum aperture of f/4.5 is relatively modest for a medium format zoom, limiting low-light performance
- ✗Weight of 1,470g makes this a demanding lens for extended handheld use
- ✗Exclusively compatible with the Pentax 645 mount, limiting cross-system usability
Videos — Pentax 28-45mm f/4.5 ED AW SR
First Impression Review: Pentax 645Z — Tyler Stalman