Thanks, Aoluain. I love my Mamiya 645 as well. However, my 80mm is the f1.9 version which uses 67mm filters. Luckily, that's the same size as a lens for another camera uses. Initially, I wasn't sure that I would like 6x4.5, being firmly entrenched in 6x6 for so long, but I've grown to really like it.