In terms of focal length, how far is the camera lens from the film when very distant objects are being photographed?
The relationship between the distance of a photographed object (p) and the focal length (f) can be expressed as follows:
(1/q) + (1/p) = (1/f)
Where 'q' is the image distance formed by the lens.
For very distant objects, 'p' becomes very large and (1/p) approaches zero, and the formula becomes:
(1/q) ≈ (1/f) or q ≈ f
The image for distant objects then forms approximately at the focal point and that is where the film is positioned. So, the distance from the film to the camera lens is approx. equal to the focal length.
Hope this helps!
I just saw your reply. If you would, please make a new post of these questions. Not sure if I can provide a detailed enough answer for these.