I have been tempted by various posts on this forum to buy a Nikkor 50mm AIs f1.2 lens. Posters have indicated that because of limitations in the design of Nikon focussing screens, the lens cannot be accurately focussed (except at infinity).

I was wondering if it would be easier to focus below infinity were one to use the aperture stop down lever with the lens set at, say f4, or am clutching at proverbial straws?