I was pretty set on getting a Bronica SQ as my first MF (yes, I'm still waffling on that) when I was reading in the manual that it uses a 6v Lithium/Alkaline battery like my AE-1. Well, I was out in the cold this morning and my AE-1's battery died on me, temporarily from the cold and that reminded me that I really wanted something fully mechanical like my preferred FTbN instead. I assume that like the AE-1, the Bronica SQ will have battery problems in extreme cold in which I often find myself shooting. The SQ falls back to a 1/500 shutter if the battery dies but that isn't really good enough. So I'm wondering, which MF cameras are fully mechanical for shutter control? Mamiya RB? Fuji GSW 690-III? Fuji GW690-III? Pentax 6x7? Is there a list somewhere? I searched the forum and google but couldn't find one, sorry if I missed some easy search parameters.