Is the voigtl nder apo ultron 90mm f 2 good in low light?

Yes, it should be good in low light, mainly because f/2 is a fast aperture. The lens gathers far more light than a typical kit zoom, which is exactly why primes are worth having. Its full frame coverage also helps, since a bigger sensor collects more light at the same framing and f-number.

It's manual focus only, so in dim light you'll need to take your time with focusing. The camera body matters as much as the lens. On the Leica M side, I'd look at the Leica M11, the Leica M10, or the older Leica M (Typ 240). Any of them fits this full frame lens, and the 90mm is a lovely focal length for portraits by available light.

Written by Claude from this site's pages.