To find the near, far and hyperfocal distance for a
specific lens, enter the focal length (mm),
aperture (f-stop) and the object
distance (whole or decimal number) in the green
areas. The program will calculate the near, far, depth and
hyperfocal distances in the blue areas.
Phil suggested that if you are photographing at aquariums, you modify a red toilet plunger to put on your lens to keep flash reflections out of your pictures!