Upload & Sell: Off
Yes, Joe and I are on a Sonnar spree. Well, more so Joe. Just received my Amedeo adapter today and gave the 50/1.5 a spin. My copy is an Opton (made in West Germany) and is coated.
A few initial observations... the coatings probably make a pretty big difference because I tried scenes with some bright sky as backlight and the lens held contrast reasonably well. Better than I expected in many situations. Bokeh character is in-line with Sonnars from this era but I think it's somewhat less extreme than the Nikkor 5cm/1.4. I don't have a ZM50/1.5 for direct comparison, but based on some web shots from it, I would guess the ZM is slightly smoother with its OOF specular highlight rendering. Compared to the Nikkor, the Opton doesn't melt into absolute gooey SA glow wide open, though it still has SA glow that will add a slight halo-edge to high contrast transitions. Nor does it seem as susceptible to extreme purple fringing like the Nikkor against very bright backgrounds. Stopped down one stop, the hard ring edges soften but the lens doesn't have the dramatic pick-up in contrast the Nikkor has. The Opton seems to have a relatively small central sweet spot. Stopping down to f/11 seems to give the best across-frame performance. This isn't a lens I'd want to use for technical purposes. Interestingly, the Canon 50/1.4, which isn't a Sonnar design, is much better than the Nikkor or Sonnar for predictability and control. Stopped down around f/8 it's pretty close to modern glass for across-frame sharpness. So... for me, the 50/1.5 Summarit, 5cm/1.4 Nikkor and 50/1.5 Zeiss-Opton Sonnar are more or less bokeh effect lenses that also can work well for people/portraiture. The Canon can do this as well, or sit in the camp of more technically proficient lenses.
So, where to start?
These are pretty much unprocessed. WB adjustment and maybe slight curves for some. Zeiss-Opton 50mm f/1.5 Sonnar, all without a lens hood:
And sorry if I hurt your eyes with the following These were given slightly more processing.
Biggest hassle with the lens is again ~1m MFD and because it sits in a Contax RF to Leica focus helical adapter that was probably made based on the actual Contax RF focus helical, the focus direction is the wrong way.