IRIX 11mm f/4 Blackstone Lens for Pentax K

BH #IR11BSP • MFR #IL-11BS-PK
IRIX
IRIX 11mm f/4 Blackstone Lens for Pentax K
Key Features
  • Pentax K-Mount/Full-Frame Format
  • Aperture Range: f/4 to f/22
  • Three Aspherical Elements
  • Two ED and Four HR Elements
Show More
Distinguished by its refined physical construction, the 11mm f/4 Blackstone Lens from Irix is an ultra-wide prime designed for Pentax K-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.
In Stock
$649.95
$55/mo. suggested payments
with 12 Mos. Promo Financing* 
Trade in your gear for cash: Learn more
Jamie P., B&H Photo Expert

True Know-How

Ask Our Experts

800.606.6969

IRIX 11mm f/4 Blackstone Overview

Distinguished by its refined physical construction, the 11mm f/4 Blackstone Lens from Irix is an ultra-wide prime designed for Pentax K-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.

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 full-frame Pentax K-mount DSLRs, this lens can also be used on APS-C 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.

IRIX 11mm f/4 Blackstone Specs

Focal Length11mm
Maximum Aperturef/4
Minimum Aperturef/22
Lens MountPentax K
Format CompatibilityFull-Frame
Angle of View126°
Minimum Focus Distance10.83" / 27.5 cm
Optical Design16 Elements in 10 Groups
Diaphragm Blades9, Rounded
Focus TypeManual Focus
Image StabilizationNone
Filter SizeGel Filter (Rear)
Dimensions (ø x L)4.65 x 4.06" / 118 x 103 mm
Weight1.74 lb / 790 g
Packaging Info
Package Weight3.11 lb
Box Dimensions (LxWxH)6.7 x 5.65 x 5.65"
See any errors on this page? Let us know

YOUR RECENTLY VIEWED ITEMS

How is the iris controlled on a Nikon F-mount ...

How is the iris controlled on a Nikon F-mount camera? Is there a 'G' style control lever? Or is it purely electronically controlled?
Asked by: Mark
The aperture is electronically controlled.
Answered by: Rob
Date published: 2021-01-11

Is there an 150mm filter holder for this lens

Is there an 150mm filter holder for this lens
Asked by: Harold
Not that I know of that we sell, there may be some coming soon from Nisi, Lee, Fotodiox, etc..
Answered by: Rob
Date published: 2020-08-05

question

What is the difference between the FireFly and Blackstone iterations of this lens? What do you get with the extra money for the Blackstone? Thank you!
Asked by: Mark
The Blackstone has a metal body and engraved numbers. The Blackstone is heavier as well. Optically they are the same.
Answered by: Jeremy A.
Date published: 2020-01-29

question

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!
Asked by: Paul R.
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.
Answered by: Doc C.
Date published: 2018-08-27

question

Can someone please explain or help me to understand how to read the hyperfocal scale on this lens? I have never had a problem using hyperfocal scales on any of my other lenses, but this one is quite perplexing to me, there are so many values on it.
Asked by: Paul R.
If you are old school and know how to use the hyperfocal scale on manual lenses, then work as you have before. If you wish, you can also use the innovative hyperfocal indication line but really it is meant for others. That is because, ever since auto focus lenses came into use, they have mostly come without manual aperture scales since they had no place for the scales to be applied. Therefore a generation of photographers has grown up not knowing what they are for or how to use them. With Irix's hyperfocal line, the new user determines what aperture they are using, moves the focus ring to line up the aperture number on the Irix hyperfocal line with the lens focus mark. Then they look to the aperture numbers on the traditional scale to see the hyperfocal distance or the area that is in acceptable focus. To old users it is not necessary, to new users it is very helpful.
Answered by: Dennis A L.
Date published: 2018-08-27

question

(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!
Asked by: Mark
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.
Answered by: fahad a.
Date published: 2018-08-27
  • y_2021, m_5, d_6, h_17CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.15
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_6
  • loc_en_US, sid_1325629, prod, sort_[SortEntry(order=LAST_APPROVED_ANSWER_SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_bhphotovideo

Close

Close

Close