The idea is that when the mirror flicks up it causes vibrations in the telescope and on the photograph. By flicking up the mirror and letting the vibrations die down you can get a sharper image. I used my home built shutter release to release the shutter and I was very pleased with the way it performed. Moon pictures were a little of the out of focus side but I didn't have time to image Jupiter as it had moved behind a tree. Tried locating a few other Messier objects and failed miserably. Eventually, I stumbled upon M13 again so imaged that as well. I think before I try this again I need to look into collimating the telescope.
I started off photographing the Moon, experimenting with the mirror lockup feature on the camera which lifts the mirror and lets the vibrations dampen off before taking the picture.