I've recently started using a Mamiya C330S TLR for a lot of my shots, and the lack of a depth of field preview facility is really causing me grief. The focus scale is (IMHO) next to useless, so even the DOFMaster program I have for my Palm PDA isn't much of a help. Throw in that I'm used to working with 35mm instead of 6x6 (and that a 6x6 80mm 'feels' to me like a 135 50mm, etc.) and time and again I'm finding that the depth of field has tripped me up, even if I attempt to focus hyperfocally. For selective DoF shots the reliability of my cackhandedness nears 100%! All you TLR shooters (especially Mamiya interchangeable lens users) - How do you manage? Any tips you can offer?