Irix 11mm f/4.0

This review is from the Amazon store:
“The Irix 11mm lens produces professional level images. Ive owned 5 similar focal length lenses from both Sigma, Nikon, and Zeiss. This lens is by far the best. If the lens had Nikon or Zeiss badging, I would expect it to sell for $1200. Super wide lenses, by their nature, are more difficult to focus because they have extreme depth-of-field. They challenge auto exposure metering because they include an extremely wide field of view. These are not the lens fault, they are the way super wide lenses operate. If you are not familiar with such lenses youll need to learn how to use them”

This review is from the Amazon store:
“This super wide lens is great for the price! Focus lock is very nice too. Highly recommended”

This review is from the Amazon store:
“Style:Firefly Mount:Nikon F
I was looking for an UWA lens for landscapes, sports & architecture. I don’t shoot wider than 18mm frequently, so I didn’t want to spend nearly $2,000 on the Nikon 14-24mm f/2.8. Just as I was agonizing over what lens to buy, IRIX had announced the 11mm f/4 Firefly and Blackstone versions. Since the optics are exactly the same in both and I wanted something lighter to carry, I went with the Firefly. The Good: 1.) This lens is SHARP even wide open at f/4. I spent a couple of hours comparing my SOOC results to other UWA lenses out there and concluded that this lens is as sharp at f/4 as some of the most expensive Nikon or Canon glass you’ll find. 2.) Being a rectilinear lens, it will render the scene with minimal distortion of lines. As long as it’s angled the right way, you don’t need to make any post-processing corrections. 3.) The Firefly version seems very well-built. It feels solid, smooth and hefty. It’s heavier than I thought it would be, even though this is the lighter build. The focusing ring is butter-smooth as long as you leave it unlocked. It has a locking ring that will either prevent you from accidentally changing the focus, or make it a little more difficult to move the focusing ring if you want more precision. 4.) It fits all my Nikon cameras perfectly. I’m using it with a D750, D610 and D500 and feel no movement when the lens is mounted. 5.) The lens comes packaged in a nice tin can, comes with a soft pouch, an extra rear lens cap and manual. Pretty neat! 6.) For an 11mm lens, the corners are actually quite usable, especially when stopped down to f/5.6 – f/10. Corner sharpness will depend on how close or far away you are to your subject. As can be expected, at f/4 the center is pin-sharp, but the corners fall off if you’re closer to what you’re shooting. That’s expected. 7.) When shooting into the sun, flaring is pretty well-controlled. 8.) According to IRIX, this lens is weather-sealed. I haven’t had any experience with that so far, but most lenses in this price range generally do not include weather-sealing. 9.) 11mm f/4 for under $600 with this IQ and build quality???? Wow! The Bad: 1.) My copy back-focused straight out of the box by a lot. I’m relying on Nikon’s viewfinder focus confirmation dot to be able to tell if my subject is in focus, so I had to AF-fine tune the lens before I was able to get optimal results. At first I thought a fine tune value of -10 would do it, but after a weekend of shooting, I was still unhappy with my results. I was beginning to think I got what I paid for. Despite the large DOF of an UWA, my subjects weren’t appearing as sharp as I hoped. I almost sent the lens back believing it’s alright for tripod work, but I intended to use it on moving subjects as well, and it didn’t seem to be working out for me. It took more than a week for me to figure out that the value actually needs to be set to -17 for perfect focus indication. Although it works great now, I’d love to be able to send it in and have it calibrated. Unfortunately it means I’d have to send it to Europe and wait weeks to get it back. This is part of the reason I wanted to take away half a point from my rating. 2.) My copy of the lens is underexposing pretty consistently by about 1 stop with all three cameras. It’s most noticeable when using highlight-weighed metering. I’m currently solving the problem by dialing in +1.0 exposure compensation, but wish I didn’t have to. 3.) There is some chromatic aberration in corners, but this is so easily fixed in Lightroom or Nikon’s Capture NX-D, that it’s not one bit worth worrying about. It’s no worse than any other UWA out there, even the very expensive ones. Unless you never process your RAW files and shoot JPEG, this is a complete non-issue. 4.) There is some minor vignetting, but once again, this is something that is easily fixed in post. I barely notice it. IRIX has developed a Lightroom profile for their lenses to address this. 5.) The cover for the lens is neat, but the mechanism that clips onto the hood is not covered in any fabric or rubber that would prevent it from scratching the outer surface of the hood when it moves around in a bag, for example. I think that small pieces of rubber would solve not only the slight movement of the cover, but also the potential danger of minor scuffs to the hood. Not a big deal, just something minor that could use a little improvement. Conclusion: The IRIX 11mm f/4 is an amazing lens when compared to what’s out there, not to mention for the price! Right now (2017) there really is nothing else like it out there. You’ll find lenses that are almost as wide, but not as sharp or as well-built, or they’re just as sharp, but contain a lot of distortion, and/or are much more expensive. Despite a couple of the more serious negatives I listed, with proper adjustments I’m getting optimal results. These issues could be unique to my particular copy and not necessarily a problem with others. I hope IRIX reads this and addresses the problem if it is more wide-spread. If you don’t mind manual focus and you need a rectilinear 11mm for architecture, landscapes or sports, in my opinion this is your best option for under $2,000.00. Nikon just released the 8-15mm fish eye lens which seems great, but if you don’t want that fish eye look, the IRIX is a wonderful alternative”