The experiment with vintage Minolta lenses ended with my decision to purchase a used Canon EF 50mm f//1.2L USM lens to use with the EOS R6. I don't consider the experiment a failure, however. Without it I wouldn't have swapped an EOS R for the R6 to gain in body image stabilization. Without it I wouldn't have reconnected with using older lenses with flaws. Both of those were necessary for me to settle on this lens.
The lens is far better used on camera bodies like the EOS R6 than on the DSLR bodies for which it was designed. Autofocus is far more precise, features like eye focus tracking where the camera automatically focuses on the eye and then follows it are incredible. Focus peaking, magnification and exposure simulation in the viewfinder render a lens like this more useable.
I posted a full size file of the vertical 9/11 monument on the mini blog for examination. There is some chromatic aberration visible but when you click on the image twice you're looking zoomed in at 200%. Here's a direct link: https://trulandphoto.blogspot.com/2023/06/a-not-disappointing-lens.html
And here are some of my first images with the lens from this morning.
Canon EOS R6, Canon EF 50mm f/1.2L USM at f/2.8, 1/4000 sec., ISO 800.
Canon EOS R6, Canon EF 50mm f/1.2L USM at f/5.6, 1/750 sec., ISO 200.
Canon EOS R6, Canon EF 50mm f/1.2L USM at f/5, 1/45 sec., ISO 200.
Canon EOS R6, Canon EF 50mm f/1.2L USM at f/5.6, 1/2000 sec., ISO 200.
Canon EOS R6, Canon EF 50mm f/1.2L USM at f/4, 1/6000 sec., ISO 400.