Back in the days, they used slow films, so it might not be only the fall-off imperfections ...
The book Hollywood Portraits by Roger Hicks and Christopher Nisperos is quite interesting
I use slow films a lot and do it handheld, so there are times when You are shooting 1 stop from wide open or just wide open.
Don't care much if there is out of focus or any focus, as long as there is an image, a moment or just a shot