Quote Originally Posted by StoneNYC View Post
The RZ67 CAN be fired from the lens itself, so triggering it with a cable can be done in mirror lock up mode, however, I suppose you're right
Stone, the RZ67 does not have a shutter, and most telescopes don't have one either! Once the mirror is up, there is nothing between the front entrance of your camera and the film back.

If 6x7 astro slides mean a lot to you and you are not afraid of some fiddling, you could try the following: focus your telescope onto a piece of ground glass, put the macro lens and some extension rings on your RZ67 and photograph the ground glass. This technique has been used by video folks to get very small DOF despite their camera's small sensors, look for DOF converter.