I have 60’s vintage Leica 50mm F2 Dual Range Summicron. It’s a nice normal lens with the ability to focus a bit closer than most RF lenses due to a second focusing cam and an optical goggle piece that fits over the camera’s rangefinder to provide correction for close range focusing. However, it doesn’t focus all that close by modern SLR standards, it’s definitely not in macro territory:
However, the lens was designed for good closeup performance, and the optical unit (glass and aperture) unscrews from the focusing mount so you can use it on a visoflex reflex focusing unit with bellows as a macro lens.
Those are expensive and cumbersome, so I never pursued it.
However, I recently discovered that Leica made an adapter that allows the front unit to connect to standard M39 mounts (I believe this was intended so you could use it as an enlarging lens). Turns out those adapters are not expensive at all. Neither is a Minolta MD – M39 adapter ring.
Does it work?
I think it does! Here’s a shot at 1/2 life size with a tamron 90mm for comparison: