During the last decade the ultra-wide segment has been dominated by zoom lenses but it seems as if prime lenses are about to enter a renaissance. Lately Nikon released a 20mm f/1.8 and we've seen a bunch of updates from Zeiss and some promising announcements from a new player (irixlens.com).

Wow. Right, that's why they call it "glass." Beyond a bit of plastic and electronic wizardry that's all this thing is: GLASS. Absolutely incredible imagery. Beautiful wide angles with no discernible distortion. Insane, insane, insane depth of field and bokeh.

I have only had this lens for about a month, but I will share my limited experience of using it. The first thing that hits you is the physical size - its a large, heavy lens (950G) and I really had to tighten the tripod up like never before when using it.

This lens is an upgrade from a Nikon 20mm f/2.8. It is close to being optically perfect. Although there is no VC, the focus is very fast and quiet. This completes a trio of Sigma Art primes - 20, 35 and 50 mm. Can't praise Sigma enough for these fine primes.

Serious back focusing issues, was out by about 20 cm from 1m away ! very disappointed as im not sure the calibration dock could have fixed such a serious problem. think sigma need to tighten up on quality control

Everything came on time as expected. Haven't had a chance to go out and use the lens yet but it looks like everything works beautifully. My fiancé says the bag is cute with the purple and gray inside lining. Yeah purple means it's hers.

this Sigma 1,4/20 lens is a really good performer fpr portrait shooting, but for landscape and architecture shootings you must stop it down, in order to increase sharpness of the edges my Fujinon lenses are much more sharper on my x-e1

+ really good sharpness in the centre wide open + stopped down better sharpness in the corners

- not so sharp in the corners - some flare wide open - expensive

Call them what you will – ultra-wides or super-wides – I love ‘em. By covering a breathtaking expanse, these types of extreme wide-angle lenses are not only capable of capturing most landscapes, they also help sweep you into that landscape, making you feel a part of the scene in the process.

In my opinion, one of the best developments to happen in photography recently is the stepped-up offerings of third party...