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IRIX 15mm f/2.4 Firefly Lens for Pentax K

BH #IR15FFP • MFR #IL-15FF-PK
 57 reviews
IRIX 15mm f/2.4 Firefly Lens for Pentax K
Key Features
  • Pentax K-Mount/Full-Frame Format
  • Aperture Range: f/2.4 to f/22
  • Two Aspherical Elements
  • Two ED and Three HR Elements
An impressively wide prime lens, the Pentax K-mount 15mm f/2.4 Firefly Lens from Irix meshes an advanced optical design with a lightweight, durable physical construction. The expansive field of view is complemented by a sophisticated optical layout that utilizes low dispersion, aspherical, and high-refractive glass elements, as well as a Neutrino coating, to render imagery with low distortion, controlled spherical and chromatic aberrations, high contrast, and natural color rendering.
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$349.95
Reg Price $474.95
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Style
Firefly
Blackstone
Lens Mount
Canon EF
Nikon F
Pentax K
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IRIX 15mm f/2.4 Firefly Overview

An impressively wide prime lens, the Pentax K-mount 15mm f/2.4 Firefly Lens from Irix meshes an advanced optical design with a lightweight, durable physical construction. The expansive field of view is complemented by a sophisticated optical layout that utilizes low dispersion, aspherical, and high-refractive glass elements, as well as a Neutrino coating, to render imagery with low distortion, controlled spherical and chromatic aberrations, high contrast, and natural color rendering.

In addition to the imaging performance, this 15mm f/2.4 utilizes a manual focus design for fine-tuned control, and incorporates a unique positive focus lock to secure the focusing position at any point for consistent, repeatable shooting. As the Firefly version of this focal length, this lens is also distinguished by a lightweight ABS plastic exterior, printed lens markings, and weather-sealing about the lens housing to permit working in trying environmental conditions.

The Firefly version of the 15mm f/2.4 lens features a lightweight ABS plastic exterior construction that is sealed against moisture and dust along the main body of the lens. The Firefly construction also incorporates a rubber focus ring for improved grip and control, and has printed focus distance and depth of field scales to aid working with pre-focusing and hyperfocal focusing techniques.
Wide-angle prime designed for full-frame Pentax K-mount DSLRs, this lens can also be used on APS-C models where it provides a 22.5mm equivalent focal length.
Two aspherical, three high-refractive index, and two extra-low dispersion elements are featured within the optical design to limit both spherical and chromatic aberrations, as well as color fringing and distortion, for improved clarity, sharpness, and even illumination.
A Neutrino coating has been applied to limit lens flare and ghosting for improved contrast and color fidelity.
Manual focus designed is benefitted by a positive focus lock mechanism to secure your focus position at any point to limit unwanted shifting of focus.
A hard click stop indicates the infinity position on the focus ring for easy use in low-visibility conditions.
Large depth of field scale benefits using hyperfocal and pre-focus techniques.
Front of lens has 95mm-diameter filter threads and the rear of the lens accepts 30 x 30mm cut gel filters to lessen the likelihood of vignetting.
Rounded nine-blade diaphragm contributes to smooth bokeh.
Includes complimentary additional rear lens cap.

IRIX 15mm f/2.4 Firefly Specs

Key Specs
Focal Length
15mm
Maximum Aperture
f/2.4
Lens Mount
Pentax K
Lens Format Coverage
Full-Frame
Focus Type
Manual Focus
Image Stabilization
No
Filter Size
95 mm (Front)
Gel Filter (Rear)
Maximum Aperture
f/2.4
Minimum Aperture
f/22
Lens Mount
Pentax K
Lens Format Coverage
Full-Frame
Angle of View
110°
Minimum Focus Distance
11.02" / 28 cm
Optical Design
15 Elements in 11 Groups
Diaphragm Blades
9, Rounded
Focus Type
Manual Focus
Image Stabilization
No
Filter Size
95 mm (Front)
Gel Filter (Rear)
Dimensions (ø x L)
4.49 x 3.94" / 114 x 100 mm
Weight
1.28 lb / 581 g
Packaging Info
Package Weight
2.55 lb
Box Dimensions (LxWxH)
6.6 x 5.5 x 5.4"

IRIX 15mm f/2.4 Firefly Reviews

Excellent lens for Bmpcc 6k

By Jorge
Rated 5 out of 5
Date: 2023-06-27

Very good lens and good quality, is just as i expected, works perfecy with de bmpcc 6k

NOT a lens for professionals

By denis
Rated 2 out of 5
Date: 2022-05-19

After using this cheap option for over 3 years, I have to confess this is not a good product for professional photographers. Seems like it was purposefully designed to be soft. I highly Do NOT recommend this line of lenses.

Happy with photos, lens features and build quality!

By Amit
Rated 5 out of 5
Date: 2022-03-25

I am a hobbyist who loves landscape and astrophotography and was looking for a cost-effective wide-angle lens to pair with my Canon R6 body. After spending a lot of time searching thru reviews and options, I finally ordered this lens as it was hard to pass on the value effectiveness of this. I was skeptical of manual focus, as I have not used an MF lens in such a very long time since my early film camera days. But I am pleased with usability, picture quality, and lens build quality for my purpose. Some pics are attached. Not seen any unacceptable vignetting in landscape shots, pretty good quality on the edges, tested from f2.5 to f22. I have not had time to take some real astro pics yet, but I did take some with imperfect lighting (see picture) and don't see any unacceptable aberration also compared to what I have seen and shot with rental Sigma 20mm, 1.4 DG HSM art lens. Included pic is 20s @ ISO 6400. As for manual focus, I realized that for most of my use cases, the hyperfocal distance is close enough that can get pretty much everything I need in focus, so focusing error is not a concern. Additional features I like: Infinity focus has a slight click, so you know that's set. Hyperfocal marker feature. Minor issues: Canon R6 reads lowest aperture as f2.5, not f2.4. Also I am using this EF mount lens on RF mount camera with convertor, so the hood is not usable as it shows up in pics. Minor stuff.

Brilliant Sharpness

By Gerard
Rated 4 out of 5
Date: 2022-01-05

So far I have used this lens on a few shoots. It definitely surpassed my Rokinon 14mm in sharpness and quality for not much more money.

Great Wide Angle Lens

By Oey
Rated 5 out of 5
Date: 2021-11-15

great lens. affordable and able to get great results.

Great value

By Neil
Rated 5 out of 5
Date: 2021-10-18

Bought this for landscape and Astrophotography. I've been pleased. Only con thus far is the lens hood can be tough to click on and off and the lens cover is par and with most lens. Again a great value for the performance. Shooting on a Canon 5DSR with tripod and Internal ND filters.

Excellent!

By Luisa
Rated 5 out of 5
Date: 2022-12-29

I use it in my studio. I needed a fast, wide lens to get enough depth of field and low-light performance. This exceeded my expectations. I love it!

Excellente.

By michel
Rated 5 out of 5
Date: 2022-08-04

Reu la lentille dans les dlai (UPS)promis par BH.Excellente lentille.Hyper focale superbement facile avec l'anneau de blocage.Cette lentille manuel fonctionne parfaitement avec le signal dans le viseur pour la mise au point.Le rendu des couleurs est parfait.Oui un peu de flare mais celui ci se contrle bien.Cette lentille est beaucoup mieux que mon ancienne Rokinon 14 mm.

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YOUR RECENTLY VIEWED ITEMS

For the Pentax mount version, will it work with a ...

For the Pentax mount version, will it work with a film Pentax camera like the ZX-5n which has Av and Tv settings or the fully manual K1000 SE? I understand that there is no aperture ring so I would not be able to select the aperture on a fully manual camera like the K1000 and the aperture would default to 22 which would be fine for my intended purpose (landscape photography with a large DoF mounted on a tripod). Was wanting this to use with a K-1 Mk II special for night sky astrophotography landscapes and also be able to use it with my old ZX-5n and a K1000 SE for daytime landscapes. I already have a 95mm night sky light pollution filter - which is why I would prefer this lens over the Roki 14mm 2.8 which won’t accept filters but does have an aperture ring and would likely work fine on my film camera.
Asked by: Roy
It will mount to the older Pentax film cameras.
Answered by: Patrick
Date published: 2020-07-09

Do this lens have Sony e mount?

Do this lens have Sony e mount?
Asked by: Anonymous
Unfortunately for the time being there isn't one.
Answered by: Ryan
Date published: 2021-08-26

¿Funcionará esta lente con la Canon EOS 800D?

¿Funcionará esta lente con la Canon EOS 800D?
Asked by: Victor
Este lente si es compatible con su camara EOS 800D (T7i)
Answered by: Luz
Date published: 2022-01-10

What is the difference between the Firefly model ...

What is the difference between the Firefly model and the Blackstone Model? Which would be better with a Canon M-50 with the M to EF/EFS adapter? Can it also be used for landscape photography? Thank you for your time
Asked by: Steven
The IRIX 15mm f/2.4 Firefly Lens for Canon EF has a Weather-Sealed ABS Plastic Housing; the Blackstone version has a Weather-Sealed Magnesium Alloy Housing. Either lens will work equally well for landscape photography.
Answered by: Boyd
Date published: 2022-10-09

Does this lens work on Nikon Z6?

Does this lens work on Nikon Z6?
Asked by: Wassim
I contacted IRIX with your inquiry. They replied that the compatibility of IRIX lenses with Nikon Z cameras (with FZ adapter) has been announced on their Instagram account on October 2018. They state that there are no issues with using IRIX lenses with the Nikon Z cameras using the FTZ lens mount adapter, so you should have no issues using the IRIX 15mm f/2.4 Firefly Lens for Nikon F on the Nikon Z-series Mirrorless Digital Cameras with the FTZ Lens Mount Adapter. The lens' focal length and aperture information will also be transmitted to the camera's EXIF data, along with exposure settings. That being said, do note that this is a manual focus lens, so you will still have to focus the lens manually when using the Nikon FTZ Lens Adapter.
Answered by: Manzell
Date published: 2022-04-01

Will this lense work with Canon RP ?

Will this lense work with Canon RP ?
Asked by: Hanh
The IRIX 15mm f/2.4 Firefly Lens for Canon EF has a Canon EF mount, while the Canon EOS RP Mirrorless Camera has a Canon RF mount. The lens can be used on the camera with the Canon Mount Adapter EF-EOS R, BH #CAMAEFRF.
Answered by: Lawrence
Date published: 2023-06-29

Hi, I use this lens with a canon EOS RP and the ...

Hi, I use this lens with a canon EOS RP and the EF adaptor. Why is the lens doesn't go down to 2.4, and get stuck at 2.5?
Asked by: Nicolas
I have similar setup (EOS r) and see same but I do not find the lens is “stuck”. When canon reports it at f2.5, the lens is wide open. And IRIX rates this lens at f2.4 which is a mathematical result of focal length and aperture diameter. Canon reports f stop numbers in 1/3 increments (typical setup). 2.5 is 2/3 of stop between f2 and 2.8. This is same on all Canon EOS camera.
Answered by: David
Date published: 2021-03-24

Is this from China ?

Is this from China ?
Asked by: Hanh
Country of origin of the IRIX 15mm f/2.4 Firefly Lens for Canon EF is South Korea.
Answered by: Daniel
Date published: 2023-07-06
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