Hi, I'm thinking of buying a Bronica SQ-A with a Zenzanon 80mm PS lens. Aside from normal photography I suspect I'll be using it for taking lots of long exposures with it. I googled and googled and couldn't find an answer.. Can anyone tell me, do the PS versions of the Zenzanon(especially the 80mm) lenses have a T setting on them for bulb photography? The S versions don't have that option, right? Another thing, when you lock the mirror, the camera doesn't drain the battery even if I leave it exposing for a long time? Thank you!