Canon - RF 50mm f/1.2L USM vs Voigtländer - APO-Lanthar 50mm f/2 SE

These two are evenly matched on the broad strokes, with the decision sitting on which individual spec advantages weigh more for your use.

Pick the RF 50mm f/1.2L USM if you care most about weather sealed. The biggest gaps in its favor are weather sealed.

Pick the APO-Lanthar 50mm f/2 SE if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are weight.

Both ship with comparable min focal, max focal, optical stabilization, so those specs don't separate the two — focus on the differences below.

Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity tells you both are well-rounded; the differences are about trade-offs, not quality.