I'll compare my new IIIG to my M6 classic.
First: the IIIG 50mm frames fill the viewfinder like a M6 with a 0.85 finder. My M6 has only a 0.72 finder. Fifties are well suited on a IIIG.
Second: the "peep-hole" for the rangefinder is bright and the size of the rangefinder is a lot bigger than a rangefinder patch on a M. The patch is so large that the superimposed images are almost the same size as the 90mm frame's height when shooting landscape position, although there is some light fall-off towards the edges. The real handicap for the IIIg's rangefinder is under dim lighting, because it lacks the split image of the M-bodies that is so helpful under low light conditions, but overall under normal use during daylight conditions I find the IIIG's finder to be as fast or faster to focus because of the rangefinder's size. The rangefinder on an M is brighter by far, but the size of the rangefinder on the IIIG is massive when compared to an M.
Thirdly: the differance in usage and view adds to my asthetic and preferance for old retro look of classic glass verses modern glass.
I am a old man; and as I age the soft corners of my vision is how I see the world more and more. Although I am using a 50/3.5 Nickel Heliar, I also am using a 50/2.0 Nickel Heliar on my IIIG and a 50 Rigid Cron on my M, both of the latter lenses known for soft corners when used wide open or stopeed down just one stop. IMHO the rangefinder on the IIIG is how human vision works, (what we see in the center is most sharp and brighter) and maybe only pro golfers like Tiger Woods don't have soft corners.
Forthly: The large rangefinder on the IIIG aids in composition, encourages and enables using the rule of thirds because focusing is not limited to the center.
What does this all mean? The M has its advantages and excells under dim low light conditions. The IIIG has a differant kind of fast focus that is better suited for more normal lighting and imposes a differant/refreshing way of composing an image. YMMV.
I will also add that my peep-hole that has the framelines on my IIIG has a yellow cast that is due to aged balsom. So far there is no separation(s), but one day I will inevidably have to have my prism reglued, and this cast and mild dimming will be gone for perhaps another fifty years. Kinda like Catarac surgery.
Calzone
