just had the chance to jump in the water (pool) with my new 12-24 on a ff and just wanted to share a few first impressions. (all shot at the 12mm end - havent got a zoom gear to fit as yet) basically performance underwater seems to be pretty similar to above - pretty good center from5-6 up, corners aree horrible at 5.6 and stay get better up to f 11 but are never great.
weighed against that is a zoom thats relatively inexpensive ando offers 122- 84degree angle on ff. only thing that comes close to angle of view and range is the nikon 14-24 and is a) a different league of lens b) less wide, and c) as far i know still doesnt offer great corners!
anyway i'll stop rabbiting on - but im pretty please with it! few sample images
f8
