I was wondering how the Hasselblad SLR works... I know my 35mm SLR has a lens, mirror, shutter, and film (in that order). The lens is unobstructed to peek through while composing a photo. A Hasselblad, with its "in the lens" leaf shutter, would get in the way of this wouldn't it? I am not sure how the shutter must be open (to compose per an SLR), then shut, flip up the mirror, fire the shutter,and let the mirror drop down again. All this with the assumption the mirror is light-tight to prevent film exposure. Is there some really simple explination I do not realize? I don't own a hassy, just REALLY curious!