This technical post is a comparison between two Zeiss ZM lenses: the Sonnar f/1.5 and the Planar f/2. For practical reasons the comparison is not done on film, but with a Sony A7. I compare jpg files.
Let’s start at f/2. Left Sonnar, right Planar
This is the full picture: the Planar has more vignetting.
Sharpness (zoom 1:1): any difference here is probably below the uncertainty introduced by manual focusing
Central bokeh (zoom 1:2): different character
Lateral bokeh (zoom 1:2):
Let’s go at f/2.8.
Sharpness (zoom 1:1): any difference?
Bokeh (zoom 1:2)