The Summicron 35mm is one of my favorite lenses. I have used my Version 3 example for 35 years. I love its perspective, the tiny size and weight and, especially, the focusing tab. Embarrassingly, I found out recently that, although the focusing tab is an extremely useful device for focusing this tiny lens, I wasn’t using it to its full potential.
I was certainly aware of using the hyperfocal distance at any given aperture as a way to ensure that everything between a given distance and infinity is acceptably sharp. And I often use zone focusing which allows you to preset the focus by estimating the distance to the subject and then setting it on the lens without having to bring the camera up to your eye.
But, I had somehow missed, even though it has been mentioned in several articles in the Viewfinder, the fact that, with any lens with a short focus “throw” (the travel of the focusing ring from the point of closest focus to infinity), you can train yourself to use zone focusing with the lens without ever looking at it.