[Brightcolours]

Yep. A 12mm f4.5 would be best to keep the weight down!

Maybe a redesign of the Voigltander? But I'm a bit disappointed with the redesigned Voigt 15; it doesn't have the corner mush but the copy I borrowed just was not super sharp and contrasty. It was fine; but clearly not as good as the FE zoom at 16 mm and you would hope for better...

For SLRs there was no such Voigtlander, a redesign of any range finder UWA won't be of much help ....

For mirrorless APS-C there is the Samyang 12mm f2:

http://www.lenstip.com/404.11-Lens_revie...mmary.html

Only weighs 245 grams. That is only 5 grams more than my Voigtlander 20mm f3.5 SL II N.