Irix 15mm F2.4 Firefly & Blackstone Review


The Irix 15mm F2.4 comes with a short, straight-to-the-point name. It does include modern multi-coatings called "neutrino" and a complex optical design.

Below are the lens specifications.

Lens Name

Irix 15mm F2.4 Blackstone

Irix 15mm F2.4 Firefly

Optical Formula

15 elements in 11 groups

Image Circle 35mm (Full frame)
Auto-Exposure Support Yes
Construction Metal, fluorescent lettering Plastic
Field of View Diagonal / Horizontal

APS-C: 88 ° / 77 °
Full frame: 110 ° / 100 °
Aperture Range F2.4 - F22
Aperture Blades 9 rounded
Aperture Ring No
Max. Magnification 0.06x (1:9)
Focus Type Manual (with focus lock)
Minimum Focusing Distance 25 cm
Internal Focus  No
Filter Thread Diameter 95mm (front), 30x30mm (rear)
Cap Plastic, pinch-type
Hood Yes, petal
Case Hard case Soft pouch
Diameter x Length 114 x 100 mm (4.49 x 3.94 inches)
Weight 653 g 581 g
Pentax Mount Designation KA
Weather Sealing Full WR Partial WR (front element excluded)
Price (US MSRP)

$675 USD

$475 USD
Launch Date

2016 PentaxForums @PentaxForums News | Reviews | Forum

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