[9] Clear on my blackmagic 12k

[43.3 mm] I've used this lens for a couple of years now, gotta say, it's a very sharp lens. I set the aperture at F8, turn the focus ring until it clicks at infinity, & I'm all set.
Keep this thing level and you'll love the results.
Using the Irix ND filters that slide in the back of the lens , allow for some interesting long exposures, without the use of expensive filter holders.
Using with my D850 is a compelling combo.
Don't use it as much as my 14mm or 20mm, but when you want everything in the frame, the Irix wins!

[43.3 mm] I've used this lens for a couple of years now, gotta say, it's a very sharp lens. I set the aperture at F8, turn the focus ring until it clicks at infinity, & I'm all set.
Keep this thing level and you'll love the results.
Using the Irix ND filters that slide in the back of the lens , allow for some interesting long exposures, without the use of expensive filter holders.
Using with my D850 is a compelling combo.
Don't use it as much as my 14mm or 20mm, but when you want everything in the frame, the Irix wins!

[43.3 mm] I've used this lens for a couple of years now, gotta say, it's a very sharp lens. I set the aperture at F8, turn the focus ring until it clicks at infinity, & I'm all set.
Keep this thing level and you'll love the results.
Using the Irix ND filters that slide in the back of the lens , allow for some interesting long exposures, without the use of expensive filter holders.
Using with my D850 is a compelling combo.
Don't use it as much as my 14mm or 20mm, but when you want everything in the frame, the Irix wins!

[11mm] Awesome lens for scenery, landscapes, cramped interiors ... really opens things up!
Packaging
was excellent, lens was inside a sturdy metal box with heavy duty foam
inserts, inside a durable cardboard box, inside a padded cardboard box
from B&H.
This lens seems very well built, gives sharp images,
and has features I wish other lens makers would use in their lenses; the
hyper-focal distance scale, click stop infinity detent, and raised
'lever' on focusing ring to name a few.
I would definitely recommend this lens as an inexpensive, lightweight, super-ultra-wide-angle lens !!!

[Metric] A very substantial and solidly built piece of glass. Excellent quality. The lens is very sharp with great color and contrast. If you're like me, you may need to work on your focusing skills since it's a manual focus lens. Usually not an issue because infinity covers a huge area in such a wide angle lens. Irix is very proud of their packaging but I found it pretty insubstantial. The can is very flimsy and thin. Not nearly as tough as your average coffee can. B&H might consider packaging this with a little extra padding. UPS, my least favorite carrier, was pretty rough with mine and the can was actually bent. Fortunately, the very nice semi-hard lens case that comes with the Blackstone version did a nice job of protecting the lens. If you need or just want a super wide angle non-fisheye lens, this is a great value.

[T22] Very well constructed. Maintains Rectilinear image despite the great angle of view. Resolution is as advertised, very sharp! Seems to maintain sharpness throughout the field of view, corner to corner. CA is quite low, and any residual can be eliminated in post production.
The only con is that the lens is quite bulky.
Comes with case, and really fancy packaging, and a built - in lens shade.
Canon would do well to provide the above, especially considering their prices!

[T22] Very well constructed. Maintains Rectilinear image despite the great angle of view. Resolution is as advertised, very sharp! Seems to maintain sharpness throughout the field of view, corner to corner. CA is quite low, and any residual can be eliminated in post production.
The only con is that the lens is quite bulky.
Comes with case, and really fancy packaging, and a built - in lens shade.
Canon would do well to provide the above, especially considering their prices!

[T22] Very well constructed. Maintains Rectilinear image despite the great angle of view. Resolution is as advertised, very sharp! Seems to maintain sharpness throughout the field of view, corner to corner. CA is quite low, and any residual can be eliminated in post production.
The only con is that the lens is quite bulky.
Comes with case, and really fancy packaging, and a built - in lens shade.
Canon would do well to provide the above, especially considering their prices!

[Full Frame] Last few years I was looking for ultra-wide lens to help me in real estate photography. Sometimes the rooms to be shot were so small so I could'n use my 15-30/2.8 and I had to proceed with 16mm fish-eye. And since I've got this Irix 11/4 and made few test shots, I have no regrets. It's perfect for any tiny place and doesn't bend the walls. The lens is sharp at 4. Being swithed to f11, it doesn't need to be focused at all. What really surprised me was an ability to take street photos. Just for fun I brought this lens to a local city event and use it for candid photography. To get a good picture I had to be VERY close to the subject. And what I did find that the people don't get scary when photographer stays within 1 meter. They think the camera was pointed somewhere out. And, what is more important, you don't need to lose time for viewfinder's look and focusing, just point and shoot.