The new IRIX 15mm F2.4 lens, looks very promising indeed.

[Theodoros]

The mechanical design & ergonomics looks to be just perfect (front and rear filters, focus lock, infinity lock), price is less than half compared to the makers own 14mm lenses (announced at 699 Euros for the premium version in Europe - 549 Euros for the "light" version), performance is promised to be top-class (remains to be confirmed) with low distortions, high flare resistance and high resolution acros the frame. http://www.dpreview.com/news/7070948464/irix-15mm-f-2-4-blackstone-and-firefly-lenses-for-dslrs-launch-this-spring

I don't know about you... but to me, it's exactly how an UW should be designed. No AF, full interface communication, filters and focus lock. If performance proves as promised, I would no way consider any other alternative even if it was at the same price. Perfect timing with the Pentax FF body announcement too... (it's offered in Nikon-E, Canon Eos & Pentax K FF mounts).

[NancyP]

The astro-landscape photographers will be all over this, assuming the coma is low. Big feature of this new lens - focus lock. Lots of astro-landscape photographers currently use the incredible bargain lens (assuming you get a good copy) Samyang/Rokinon/Bower/etc 14mm f/2.8 - but are having trouble focusing the darn thing to true infinity. Even 10x live view is hard to focus perfectly. Lots of people focus during daylight and then tape down the lens focus with Sambowyang lenses.

[Theodoros]

 The thing with the Samyang (and relatives) is that other than the focus, distortions are at extremely high level... The IRIX claims less than 2% of distortions and on the graph they provide http://nikonrumors.com/2016/03/19/new-irix-15mm-f2-4-full-frame-lens-for-nikon-f-mount.aspx/#more-103187 it looks uniform too, which should mean that correction of it in post would be very easy and without loss of FOV... They also claim the most resistant to flare/ghosting UWa lens in the market out of all (another decease that comes with the focal length) and they also claim that every single lens passes a QC & calibration check before it leaves production which should mean no "lemons".... Very promising indeed and at a price to rave if all that proves to be true, especially as they also claim construction to be all metal (aluminium/magnesium) and up to "German" pro levels....

Heck, they promise a lens that would beat the Zeiss 15mm f2,8 optically and on ergonomics, would compete directly with it for build quality and toughness and all that at 28% of the price!

[NancyP]

I have never used the Samyang for architecture-containing shots, for that reason. I do have an Adobe lens profile for it, contributed by a German photographer. Big time vignetting at f/2.8! So, it will be fun to see how this Irix lens performs.

[Paul2660]

If it ships as spec, I am looking forward to it for sure.  Just wonder well coma will be corrected at F 2.4.  Love the ability to lock infinity focus. 

Paul C

[Theodoros]

If it ships as spec, I am looking forward to it for sure.  Just wonder well coma will be corrected at F 2.4.  Love the ability to lock infinity focus. 

Paul C

Usually, the lenses that excel with flare resistance are also superior in handling coma...