I am trying to get the precise focal length used for a stack of photographs taken with various focal length. See the following link.
My problem is that even if the photographs are obviously focusing on different part of the image, the focal length given in the metadata is always the same. Is there a way to have precise information on this?
(For those interested: I am trying to build a depth map from a stack of photographs. To do that, I need to get the precise focal length used. I am no professional photographer, still I'm getting more and more interested with those things...)
EDIT : I may need to be more precise. If you download the rifle focus stack, you will have 24 shots focused on 24 different parts of the image. Still, the focal length you can read in the metadata is always 9.7mm.