Why is the optical quality higher with the G1 over the SLR lenses?
A. The G1, being a rangefinder, has a closer lens flange to film distance than an SLR, since it does not have an SLR mirror. This closeness, allows lenses to be designed without the normal compromises introduced into an SLR. Distortion and contrast are both enhanced in a rangefinder camera, with all other factors being equal.