@rayvonn It is, optically and mechanically, and it sure is a rewarding lens to shoot with because it yields interesting results - though if it is a suitable lens for me personally is different question. It forces me to do things differently, which essentially is a good thing in terms of the challenge. However, I'm still not able to previsualise reliably with the 12mm after almost three weeks, meaning that I have problems taking accurate shots in a hurry (think street, people or fleeting moments), and that's costing me shots. I can do this quite well with the 17mm (or any 35mm-e or 40mm-e), and even with the GR, though that takes a little getting used to every time. Heck, I can get lots of usable *hip* shots with any lens of that kind ... not so with the 12mm (yet?). Anyhow, I'm getting better: I now take the extra step or three towards my subjects - if that's possible, that is.