ce reducing the size of the small circle. By using a sufficiently small stop this circle will be apparently a point, and the image of B will be practically in focus at A', It will be seen that, using the same lens, to halve the diameter of the circle of confusion, we must halve the diameter of the… … lens, then to represent the 8 in. lens every line must be made twice as long, consequently the diameter of the circle of confusion will be twice as great, hence to reduce this with the 8 in. lens to the same size as with the 4 in. lens, we must use a stop of abso- lutely the same size on each, or…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
