I guess you know by now that I am a sucker for the renditions achieved by certain legacy lenses.
I am certainly not talking about all old lenses nor am I touting that for general use, these old lenses are the equal of today's modern glass. A cheap modern 50mm f/1.8 will run rings around most of these lenses when it comes to sharpness and lack of optical flaws. Of course, the modern 50's are equipped with auto focus capabilities.
However, used correctly, the optical flaws in many of these old lenses work to achieve beautiful and artistic imagery. One of the neatest lenses I have come across is the Meyer Gorlitz 50mm f/1.8 Oreston. This lens was produced for many years as a kit lens for the Pentacon type cameras made in East Germany...
https://www.flickr.com/search/?text=Oreston
As you can see in these images, the nest way to use this lens is for relative close ups imagery! taking advantage of its "magical" bokeh. However, this busy bokeh may not be everyone's cup of tea. I like it for certain images and don' like it for others...
The Oreston is avaiable in M-42 and Exaxta mounts and has one capability that is not matched by many of the older type lenses. It is fairly close focusing at .3 meters allowing closeup photos without the need for extension tubes. It is a relatively inexpensive lens, usually found between $30 and $60 USD. I have one, in a M-42 mount, coming from an eBay seller in the U.K. and can't wait to try it on my A6500 and my Canon 6D Mark 2,,,