Distinguished by its refined physical construction, the 11mm f/4 Blackstone Lens from Irix is an ultra-wide prime designed for Nikon F-mount DSLRs. As a rectilinear lens, the advanced optical layout makes use of aspherical, extra-low dispersion, and high-refractive index elements to control distortion and aberrations for accurate, and sharp rendering with a high degree of clarity and color accuracy. Additionally, a Neutrino coating has also been applied to the lens to control flare and ghosting for improved contrast when working in strong lighting conditions.

Beyond its optical assets, this 11mm f/4 lens also sports 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 Blackstone version of this focal length, this lens is also distinguished by an aluminum and magnesium alloy exterior, engraved lens markings with fluorescent UV paint for high visibility, and extensive weather-sealing about the lens to permit working in harsh environments.

Nikon F-Mount/FX Format    Aperture Range: f/4 to f/22    Three Aspherical Elements    Two ED and Four HR Elements    Neutrino Coating    Manual Focus Design with Focus Lock    UV Fluorescent Engraved Markings    Depth of Field and Focus Distance Scales    Weather-Sealed Magnesium Alloy Housing    Rounded Nine-Blade Diaphragm

The Blackstone version of the 11mm f/4 lens features a durable aluminum and magnesium alloy housing and weather-resistant exterior along with inner seals, and an extra seal at the front element, to protect against dust and moisture intrusion. The metal exterior also distinguishes itself with an anti-scratch finish, and sports engraved focus distance and depth of field scales with fluorescent UV paint for high visibility when working in low-light conditions.

Ultra wide-angle prime designed for FX-format Nikon F-mount DSLRs, this lens can also be used on DX models where it provides a 16.5mm equivalent focal length.

Three aspherical, four 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.

Built-in petal-shaped lens hood blocks stray light in order to reduce lens flare, and also protects the front element of the lens.

Rear of the lens accepts 30 x 30mm cut gel filters.

Rounded nine-blade diaphragm contributes to smooth bokeh.

Includes complimentary additional rear lens cap.

Related Questions and Answers

Q: 1. Can we get ND filter for this lense ?

A: Yes, But a adapters are needed. Please look into the following item. Cokin Universal X-Pro Series Filter Holder Adapter Ring https://bhpho.to/37clouY Cokin X-Pro Series Filter Holder https://bhpho.to/3C9fTLZ

Q: 2. What is the difference between Firefly lens vs Blackstone lens?

A: Irix 11mm f/4 Firefly and Blackstone share the same specifications. The difference is in the build quality. The blackstone is stronger made of durable aluminum and magnesium alloy. The firefly lens is made of a lightweight ABS plastic exterior construction.

Q: 3. Is this compatible with an RF adapter on a Canon RF body? I read somewhere that it requires a firmware update installed by IRIX.

A: The IRIX 11mm f/4 Firefly Lens for Canon EF can be adapted to a Canon R-series mirrorless camera, but the operation would be fully manual, and there would be no EXIF data. No firmware update is needed since it is entirely manual.

Q: 4. Can anyone tell me how to read/use the hyperfocal scale on this lens? I know what hyperfocal focus is and on most other lenses I know how to use it, but the scale on this lens is truly perplexing to me - specifically, why are there multiple aperture values on both the left and right sides of the centre mark? And there's also another hyperfocal marker above the distances as you approach the infinity mark. So far I've only been able to test it visually by taking the same photo at different focus values and comparing them on my computer to see which are the most in-focus. This is by no means a very technical approach to achieving the proper focus, so I'm very interested in learning how to properly use the hyperfocal scale on this lens. Thanks in advance for any information anyone can provide!

A: The aperture scales on the left and right of the focus mark indicate the approximate distances from the focal plane of the camera within which the image will be acceptable sharp at the current focus setting. It's referred to as a depth of field scale. The hyperfocal scale allows you to set your focus to the approximate hyperfocal distance for your current aperture, by aligning the f/number on the scale with the center focus mark. Irix has a good article on their site explaining DoF, hyperfocal distance and how to use both scales.

Q: 5. (Please ignore or delete my previous question about the difference between the FireFly and Blackstone iterations of this lens -- it is answered in the Overview -Duh! - My bad.) Are the FireFly and Blackstone editions identical in terms of image quality? Thank you!

A: yes Mark the firefly and the blackstone are identical in image quality. The only difference is between them is that the blackstone is fully weather sealed.

Q: 6. Would the Sigma MC-11 adapter for Canon EF to Sony E mount work on this lens?

A: Yes the IRIX 11mm f/4 Firefly Lens for Canon EF compatible with the MC11.

Q: 7. is it compatible with Blackmagic Pocket Cinema 6K Pro?

A: Yes, IRIX 11mm f/4 Firefly Lens for Canon EF is compatible with Blackmagic Design Pocket Cinema Camera 6K Pro. Both products are desing with Canon EF mount.

Q: 8. What mm size UV protective filter fits this Irix 11mm Blackstone Lens?

A: Due the shape of the front element on the IRIX 11mm f/4 Blackstone Lens for Canon EF, it doesn't accept screw in UV protective filters.

Q: 9. Will this work on the BMPCC4K with a Metabones Speedbooster (MFT to EF) ? Will there be vignetting?

A: Both the 0.71 and the 0.64 Metabones Speedbooster, show little to no vignetting.

Q: 10. How is the iris controlled on a Nikon F-mount camera? Is there a 'G' style control lever? Or is it purely electronically controlled?

A: The aperture is electronically controlled.