The page includes a full-range aperture series for each of the thirteen (13) lenses covered. I also discuss the reasons behind color shading, and some alternative lenses.
The lenses can be viewed together, or by-brand: Leica M (6) or Zeiss ZM (5) or Voigtlander M (2).
I hope to add more lenses as soon as I can get my hands on more.
The controls are iPad and iPhone friendly, and any two apertures can be compared from any two lenses with the “two-way” option, or used as a grid as shown below.
Reduced size screen shot below.