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Irix 11mm F4 Blackstone Review RSS Feed

Irix 11mm F4 Blackstone

Sharpness 
 9.0
Aberrations 
 8.7
Bokeh 
 7.7
Handling 
 9.3
Focusing 
 9.3
Reviews Views Date of last review
3 16,576 Fri August 23, 2019
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Recommended By Average Price Average User Rating
100% of reviewers $738.67 9.67
Irix 11mm F4 Blackstone

Irix 11mm F4 Blackstone
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Irix 11mm F4 Blackstone
supersize
Irix 11mm F4 Blackstone
supersize
Irix 11mm F4 Blackstone
supersize
Irix 11mm F4 Blackstone
supersize
Irix 11mm F4 Blackstone
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Description:

The Irix 11mm is a rectilinear ultra-wide angle prime lens for the 24x36mm full-frame sensor. The lens is manual focus and as of its launch in September, 2017, this is the widest rectilinear (non-fisheye) lens available in the full-frame format for Pentax.

This lens comes in two versions: a cheaper Firefly and a more expensive Blackstone (this entry).  The Firefly is made of plastic and is thus lighter, while the Blackstone is made of metal and has engraved lettering.  Both versions share the same optics and have partial weather sealing (excluding the front element).

The lens has three aspherical elements, two ED and four HR elements.


Irix 11mm F4 Blackstone
© www.pentaxforums.com, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
No
Diaphragm
Automatic, 9 blades (rounded)
Optics
16 elements, 10 groups
Mount Variant
KA
Check camera compatibility
Max. Aperture
F4
Min. Aperture
F22
Focusing
Manual
Min. Focus
27 cm
Max. Magnification
0.077x
Filter Size
Internal Focus
No
Field of View (Diag. / Horiz.)

APS-C: 105 ° / 95 °
Full frame: 126 ° / 117 °
Hood
Built-in
Case
Included
Lens Cap
Included
Coating
Multi-coated
Weather Sealing
Partial
Other Features
Focus Clamp,Rear Filter Mount
Diam x Length
118x103 mm (4.65x4.06 in.)
Weight
790 g (26.8 oz.)
Production Years
2017 to present (in production)
Pricing
$449 USD current price
Reviews
User reviews
In-depth review
Notes
Accepts 30x30mm gel filters at the rear
Variants
  • Blackstone (this lens)
  • Firefly

Buy Lens: Buy the Irix 11mm F4 Blackstone
In-depth Review: Read our Irix 11mm F4 Blackstone in-depth review!
Price History:



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Author:
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New Member

Registered: June, 2016
Posts: 10

2 users found this helpful
Review Date: August 23, 2019 Recommended | Price: $600.00 | Rating: 9 

 
Pros: tank like, great focusing, weatherproof
Cons: blurry edges, flare
Sharpness: 8    Aberrations: 8    Bokeh: 6    Handling: 10    Focusing: 9    Camera Used: K1   

This is one of my favorite outdoor lenses. You get extreme FOV. You get a bombproof lens that can take the elements. It feels great on the K1. And, you get fantastic manual controls. Overall it's a standard part of my bag when out in the wild. That said, I find it doesn't get as much use as my 14mm or 20mm Roki lenses, as it suffers from lens flare and lacks some crispness on the edge that I prefer.


   
Junior Member

Registered: January, 2018
Posts: 47

3 users found this helpful
Review Date: October 27, 2018 Recommended | Price: $800.00 | Rating: 10 

 
Pros: wide FOV, good build quality, image quality at the center, infinity lock
Cons: size (the lens is very large), with some reservation: image quality in the corners
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 9    Focusing: 9    Camera Used: K-1   

I have now had this lens for a few months and I think I can now sum up what I have learned.

There are two main rules I have learned to follow with it:
(1) Keep the camera level. Luckily K1 has the tilt level indicators. Also, I always take an additional half second to check my vertical lines before releasing the shutter.
(2) Keep people away from the outer fourths of the frame. It is the center area, at the maximum to the 1/3 points, where people should be. Otherwise, they will not look natural / they look fatter than they usually do etc. Same applies to any round object. This is because of the nature of the lens i.e. ultra wide angle and not an actual fault.

The focusing scale feels inaccurate. Infinity is where it should be, but e.g. the distances around 2m and shorter on the scale do not match actual focusing distance in my opinion. My eye, through the viewfinder, repeatedly tells me to set the focus somewhere else than where it should be according to the scale on the lens, and I have also noticed that images that I have focused using just the scale, tehnd to be just little bit out of focus. I have not made any systematic tests which would immediately confirm if this is really the case, just wanted to mention this small detail.

The lens cover first felt good but I managed to loose one of the two clips within about first week of using the lens, and the cover does not stay in place properly now. Losing the clip was probably due to repeatedly removing the camera + lens from a bit toot tight bag so it is partially my fault. However, my other lenses (including ones larger than this) have all survived the same treatment. I think the lens cover clearly is not as robust as the actual lens design.

The negatives out of the way, this is an incredible landscape and interior / architecture lens. For landscapes, this opens up some new perspectives where you can fill the frame with something close to you and still have a very wide field of view for the background.

For night / star landscapes / astrophotography, this lens is great.

For me, getting Irix 11mm has left the Pentax 15-30mm almost completely unused for the summer. The 15-30 is superior in some occasions such as event shooting because of its AF, but for the last few months, I have been doing mostly outdoor and landscape photography, so the Irix 11mm has been the choice. The tricky 11mm FOV works best in nature, but I have also found it very satisfying indoors, being able to capture scenes which would be impossible with any other lenses.

Edit: corrected a few typos.
   
Forum Member

Registered: June, 2016
Location: Gislev
Posts: 87

2 users found this helpful
Review Date: June 5, 2018 Recommended | Price: $816.00 | Rating: 10 

 
Pros: Finish and Build, Image Quality
Cons: Size and Weight
Sharpness: 10    Aberrations: 10    Bokeh: 8    Handling: 9    Focusing: 10    Camera Used: Pentax K-3 II   

After reading and watching YouTube reviews on the Venus Laowa 12mm, I decided on the Irix 11mm Blackstone - and I'm glad I did:

I don't care much for pixel peeping, but even at 100 pct. in my Affinity photo editor sharpness looks gorgeous! More than just satisfactory and certainly as great as HD Pentax Limiteds.

I gave the lens a 8 in Bokeh - Bokeh isn't a forte of any super wide - The Irix is more than satisfactory in real world usage, which is apertures between 8 and 16.

The lens produces great contrast, bw tonality, micro contrast and ability to retain information in shadows and highlights.

Flare is very well controlled - I have an old 18 mm Nikon lens from the film days, and this lens is no match for the Irix 11 mm(Nikon lens on full frame, Irix on APSC). The Nikon lens can, on the other hand, be coaxed into making the most glorious flares ... which you guessed I do love to use creatively. That's not at all easy to get from the Irix 11 mm - unless you really put some effort into it (and still: Film era lenses are much better and more delicious in this department).

When turning back to Pentax from years in diaspora (read Nikon), I was certain that I wouldn't buy nor use third party lenses for my camera - I have a pair of Sigma Arts for my Nikon D810, and I hate the travel direction of the focus ring: I simply can't get used to turning the focus ring the wrong way around.
One of the long row of great things about the Irix lenses is, that the focus ring turns clockwise for infinity! (It seems as if, Irix lenses give you the travel direction of your camera system: Photos of the Canon version shows Canon specific focus travel. Irix really takes photographers and photography serious!)

On top of that, you have a dust and water proof lens, aperture adjustment in camera, gel filter holders, built in lens hood - and a great build and handling. It even comes in a delicious metal box with two caps for the mount and a hard case.

The downside is it's size and weight. And I do love the the excellent and compact Limiteds - a real asset of Pentax and the APSC format!

Highly recommended.


EDIT:

WARNING:


Even though this lens is said to sport a Pentax KA-mount you cannot and should not mount it on an analog Pentax body!!!

Apparently the Irix guys goofed up the K-mount on their lenses. This is a serious flow in my world. I had planned on using this lens for analog photography on my Pentax MZ-S and my Super A. But it's a no go!

My guess is that the omission of the mechanical Aperture Simulator Slot on the Irix lenses is the culprit (or the engineer who came up with the idea of omitting it). All Pentax lenses have regardless of K-mount version and lens age has this slot.

The result is, once you've slid the lens into the mount, you can't turn it: It's stuck!

I contacted Irix on the issue and supplied a lot of photos of the mounts of my Pentax lenses and camera bodies and had a nice dialogue with the customer service. It ended up asking the Irix engineers for a 'solution' - but I haven't heard a thing in three months ...

This let down makes me wish I'd chosen another brand of super wide angles ... however friendly the guys at customer support are and however much I love the lenses for their IQ on digital bodies.
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