I had the 50 Cron before on the M10-R, but sold it due to the low contrast and subdued color. I've since repurchased it, and it's found new life on the M10M. Not only does it render nicely on the monochrome sensor, but the size, weight and handling is excellent compared to my much heavier 50 Lux Black Chrome.
Here's a few shots I took over the weekend, most all taken at f/2. Ignore the aperture shown in the EXIF, as Leica M cameras only guess at aperture. But I did want to show EXIF so that the ISO for each shot was shown.
No color filters used. I only had a Breakthrough Photography UV filter on it. So far the BP filter is the best I've tried and the most like shooting with no filter on the lens at all – runner up would be the Zeiss T* UV filters, which I have on all my other M lenses. Thumbs down to B+W MRC Nano Clear as well as the Leica brand UVa filters, both of which can induce soft corners at infinity focus on certain M lenses.
Some of these shots have film grain added in LR, but I'm not sure that will be evident on these reduced-size images. I've found that adding grain in post can help recover (not really recover, but patch-over) small areas of blown highlights. Added grain in post is especially good at making specular highlights not look as harsh.
Side note that I've switched from C1 to LR for my Leica images. It feels like LR handles the monochrome file rendering and Leica lens corrections with better finesse.
