IRIX 11mm f/4 Firefly Lens
The Irix 11mm f/4 Firefly is a 11mm f/4 lens designed for Canon EF, Nikon F, Pentax K mount cameras. Check GearFocus for current availability, with buyer protection on every purchase.

IRIX 11mm f/4 Firefly Lens
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Lens Overview — Irix 11mm f/4 Firefly
Key Features — Irix 11mm f/4 Firefly
11mm Ultra-Wide Prime: A fixed 11mm focal length delivers an expansive field of view well suited to landscapes, architecture, and interior photography.
Full-Frame Coverage: Designed to cover full-frame sensors without crop-related vignetting on any compatible DSLR body.
Manual Focus Only: A dedicated manual focus ring gives photographers precise, repeatable control, making it practical for astrophotography, landscapes, and tripod-based work where autofocus is unnecessary.
Three-Mount Compatibility: Available in Canon EF, Nikon F, and Pentax K mounts, covering the majority of full-frame DSLR systems.
f/4 Maximum Aperture: A constant f/4 aperture provides consistent exposure across the frame, though it is best suited to well-lit conditions or use on a tripod.
790g Build Weight: At 790g, the lens is substantial enough to feel well-constructed while remaining manageable for field use.
Lens Specifications — Irix 11mm f/4 Firefly
| Spec | Detail |
|---|---|
| Use Cases | Astrophotography, Travel |
| Lens Type | Ultra Wide-Angle |
| Format | Full Frame |
| Zoom/Prime | Prime |
| Focal Length | 11mm |
| Maximum Aperture | f/4 |
| Camera System | DSLR |
| Lens Mount | Canon EF, Nikon F, Pentax K |
| Autofocus | No |
| Focus Type | Manual |
| Image Stabilization | None |
| Filter Thread | 95mm |
Description — Irix 11mm f/4 Firefly
The Irix 11mm f/4 Firefly is a manual focus ultra-wide-angle prime lens built for full-frame DSLR cameras. With a fixed focal length of 11mm and a maximum aperture of f/4, it delivers wide-angle coverage suited to landscape, architectural, and night photography where the scene demands breadth. The lens is offered in Canon EF, Nikon F, and Pentax K mounts, making it accessible to photographers across three of the most widely used DSLR systems.
Weighing in at 790g, the Firefly is a substantial but well-proportioned prime for its class. The manual focus-only design means there is no autofocus motor involved, which simplifies the optical construction and puts control directly with the user. There is no image stabilization on board, consistent with the lens's manual, deliberate-use orientation.
As a prime lens in the ultra-wide-angle category, the 11mm Firefly is a single-purpose tool that excels when maximum field of view on a full-frame body is the goal.
Pros — Irix 11mm f/4 Firefly
- ✓Ultra-wide 11mm focal length covers expansive scenes on full-frame sensors
- ✓Compatible with three major DSLR mounts: Canon EF, Nikon F, and Pentax K
- ✓Full-frame format coverage ensures no crop-related vignetting on compatible bodies
Cons — Irix 11mm f/4 Firefly
- ✗No autofocus support, which may be limiting for action or fast-moving subjects
- ✗Maximum aperture of f/4 is relatively modest for low-light shooting
- ✗No image stabilization, which can be a challenge at slower shutter speeds
Reviews — Irix 11mm f/4 Firefly
Videos — Irix 11mm f/4 Firefly
Irix 11mm f/4 ' Firefly' lens review with samples (Full-frame and APS-C) — Christopher Frost
Frequently Asked Questions — Irix 11mm f/4 Firefly
Which camera mounts is the Irix 11mm f/4 Firefly compatible with?+
The Irix 11mm f/4 Firefly is available in Canon EF, Nikon F, and Pentax K mounts. All three are DSLR-system mounts, and the lens covers a full-frame image circle on any of them.
Does the Irix 11mm f/4 Firefly have autofocus?+
No. The lens is manual focus only, with no autofocus capability. This is a deliberate design choice that suits photographers working in controlled shooting environments such as landscape, architecture, or night photography.
Is this lens compatible with crop-sensor DSLR cameras?+
The lens is designed as a full-frame lens but will physically mount on any compatible Canon EF, Nikon F, or Pentax K camera body, including crop-sensor DSLRs. However, the specifications list its format as full frame.
Does the Irix 11mm f/4 Firefly have image stabilization?+
No. The specifications confirm that image stabilization is not present on this lens. Photographers should account for this when shooting in lower light or at slower shutter speeds.
How heavy is the Irix 11mm f/4 Firefly?+
The lens weighs 790g, which is a solid but manageable weight for an ultra-wide full-frame prime intended for DSLR systems.
Can I use filters with the Irix 11mm f/4 Firefly?+
The filter thread size is not listed in the available specifications. We recommend consulting Irix directly or checking the product documentation to confirm filter compatibility before purchasing accessories.

