Use of a lens’s focus distance scale and depth of field markings enable you to adjust the focus ring so that a ‘zone’ of the scene will be sharp, within defined near and far limits.
This is the focus distance for a given focal length and aperture combination at which everything from the closest possible point to infinity will appear sharp.
Manual focusing is possible with all of the lenses on test. However, the rotational travel of purely manual focusing lenses is typically much greater, which enables more precise focusing.
Aperture ratings are usually quite ‘fast’ – between f/1.4 and f/1.8. The Irix, Samyang 14mm and Zeiss lenses are a little slower, between f/2.4 and f/2.8.