An interesting site with lots of information about 35mm photography and film vs digital techniques is 35mmc.com. Here for example is a very clear and concise d

An interesting site with lots of information about 35mm photography and film vs digital techniques is 35mmc.com. Here for example is a very clear and concise discussion of depth of field and the factors that control it (such as aperture, focal length): https://www.35mmc.com/25/07/2016/basic-optics-photographers/ https://www.35mmc.com/25/07/2016/basic-optics-photographers/