madNbad
Well-known
I mostly use it with film and don't own a digital M body. I've tried it on the Sony A7II a couple of times but not enough to notice anything negative. I sold off my M gear a couple of years ago to fund some much needed home improvements. As I have been replacing lenses, the Ultron came onto the market about the same time I bought a M4 body. The decision was easy for me. I could justify the price of an Ultron, which offers about 95% of a Summicron performance and use the money for other lenses. If I was to have just one lens, the C-Biogon would be high on the list. With a smaller larger aperture, the Zeiss will offer less vignetting but having the Ultron having an extra stop is a nice feature. The Zeiss design is from the late 1990s' whereas the Voigtlander benefits from the latest computer aided designs and coatings. The major complaint about the Ultron is it's ability to focus to 0.58 meters. Great if you're using it on a mirrorless camera, not so great if you're used to the hard stop for minimum focus. Over all it really is a flip of the coin about what is more important. The differences are small and from having owned both, I loved my Summicron, it was my only lens for years, the Ultron has seamlessly filled it's place.
