his is some distinct 11 kind of lens, with an extraordinary power of focusing all objects near and far in one plane. There is no inherent quality in any lens that makes it “fixed focus“ ; it is such when it is immovable and that is all. Any lens can, therefore, be made “fixed focus”, but the extent… … objects do not focus at the same point. For instance in the exag- gerated diagram shown herewith, we will assume that B is the point at which objects 100 feet distant will focus and that A is where objects 10 feet distant will focus. Now the distance be- tween A and B will vary in ratio to the…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
