Sometimes the curving effect is very surreal, a bit like Inception etc.
My camera doesn't meter with it fitted, but I'm used to guesstimating exposure and only had a couple of duds, and on a digital camera a trial photo or two isn't much of a problem. My initial thoughts are that this will be fantastic in areas with interesting architecture etc., and that I really ought to carry another, longer lens when I use it, since it's a very specialised optic and isn't much use for general photography.
The full album is here
Also posted at https://ffutures.dreamwidth.org/2116047.html, where there are comments. Please comment here or there using OpenID.