The first one is what you see with your eyes.
*magnification number are all measured with 50mm lenses in infinity.
The top right is the viewfinder of ZX-M. 92%, 0.77X, 1.7 stops brightness lost.
The bottom left's the FM-10. 92%, 0.84X and 1.9 stops
The bottom right's the OM2000. 86%, 0.94X and 1.9 stops.
* for your information, here are the viewfinder spec. of some MF and AF cameras.
Contax AX ____95%__0.73X__2.2 stops
F5 __________ 99%__0.75X__2.4 stops
R8 __________98%__0.76X__1.6 stops
G2 __________91%__0.54X (with 45mm lens)__rangefinder
Elen IIe_______90%__0.72X__2.0 stops
ZX-5n________92%__0.78X__2.0 stops