I haven't found a way to assign a button to manually magnify the screen on the GM5 in shooting mode to check critical focus when using the 12-32 lens. I know Manual focusing mode does it but using the touch screen to change focus is really clunky, so I'd rather use a quick button to quickly magnify/enlarge the screen to check if AF is spot on or not. Any ideas?
I haven't found a way either, but you can still AF in MF mode - there's a touch button to do that. As long as you stay in MF mode, you can AF and check the result in magnified view.
Two ways I know of on the GM1, and perusing the GM5 manual it seems the same (p145 here: https://concierge.panasonic.ca/pcs//viewing/ALL/DMC-GM5P/OI/sqw0047/sqw0047.pdf) 1) flip the AF dial to MF, then press the left d-pad arrow. 2) use the 'Pinpoint' AF mode, hold the shutter at half press for enlargement.
I still need to read the downloadable GM1 manual because I have a bunch of questions on mine. I wish I could use the useless red record button to magnify...or at least the function button. Pushing left on the D-pad with my right thumb while holding the camera and a big adapted lens with my left hand is not comfortable.