Well there are plenty of lenses that I'm considering but my biggest concern is not the sharpness/character/bokeh but getting a darn filter and hood on there. Here are the following lenses that I am interested in: -Leica 50mm f2.0 Summitar or Leica 50mm f2.0 Summicron (collapsible) -Leica 50mm f3.5 Elmar -Leica 35mm f3.5 Summaron I believe all of these can be had at reasonably fair prices and are relatively common. They appear to meet my standards for being small and high quality. Now, my primary concern is in the filters and hoods. 1. How is the quality of the old Leica filters (Elmar/Summaron take A36 and the Summitar takes L-type)? 2. Any experience with a DIY solution? Eg. replacing the old glass with modern glass? 3. For those that adapt to E39, what was your method and lens shade? 4. Any of the OEM shades for these things collector pieces?