New on the market, the Swiss designed Korean made IRIX Firefly 15mm f2.4 represents a really high quality option for landscape and architecture photographers on a budget. Below are some shots of the Mount Royal Universtiy Riddell Library and Learning Centre.
It offers low distortion with a conventional spherical shape and requires relatively minimal software correction.
Some of the quirks include vignetting throughout most apertures; this, of course, being most severe wide open at f2.4. Additionally, the results are mixed with flaring and ghosting. Although I have not tried this, other reviewers have demonstrated a very peculiar intense circular flare when pointing the lens directly to the sun. Hasn't been an issue for me so far.
As with all ultra wide lenses, there needs to be some love and attention given to a plumb and level composition. This generally make even lighter work of your post processing workflow. The Irix is very easy to compose and work with in the field.
You might have noticed by now that my images seem to be stuck using f8. This is perhaps because of one of the most unique aspects of this lens. As a fully manual focus lens, the Irix is likely one of the only contemporary lenses to have included a marked infinity + hyperlocal distance scale. The only thing its missing is an aperture ring on the lens for those craving a nostalgic vintage lens experience. Not only this, but they have created a mechanical friction point at infinity focus (the infinity click). This allows you to find infinity focus by touch. Combine this by setting the aperture to f8, f11, or f16 and you can achieve edge to edge focus, likely down to a few feet in the foreground. Finally, you can lock the focus position at any distance if you are shooting architecture and landscapes without resetting or adjusting focus throughout the shoot. Can't wait to get an ND filter for this, ...except that its a 95mm diameter. YUP 95mm. At least Irix provides a rear gelatin filter slot for a more cost effective option.
But wait, there is more. With the ability to open the lens up to f2.4, and by focusing on your subject close to the front element, you can exercise some creative licence and get some pretty intense perspectives, ....and bokeh.
All in all the Irix is a cost effective, low distortion, fast, well built and well designed ultra wide angle lens. Some more reviews of this lens can be found below. One of my favourites is from Christopher Frost on the Blackstone version of this lens: