I'm a newbie to large format and have just bought a Polaroid 545 to use on my 4x5 Speed Graphic (graflok back). My question concerns how to attach and focus with the 545 back.

1) Does the 545 back go between the camera and the ground glass?

2) Is it possible to focus on the ground glass without having to remove the 545 back each exposure? Do I need to keep putting the 545 back on and off the camera in order to use the ground glass?

TIA from a greenhorn,
R.J.