This is the reason I don't use the Ultron 35 f1.7 much these days. It's the Voigtländer Nokton 35 f1.2 II lens. It really is a beast, heave but built like a tank. You get the feeling it really is undestructible. Since I was purchasing this not really cheap lens I also purchased the Voigtländer adapter to go with it. It just fits in beautifully with this lens and everything works as it should. A fantastic lens to use and renders the images quite like the Leica magic you see in some images.
If you're after a bright lens for your system in the 35mm range, this is the one to get. You won't regret it. Worth every penny.
Talen with an Olympus OM 100 f2 lens mounted on the Olympus E-Pl1.