A 35-mm camera equipped with a 40-mm focal length lens is used to photograph a tree 17 m tall. If a 32-mm high image of the tree on the CCD sensor is required, how far should the camera lens be from the tree?

Question

Show Work Please!

Thank you so much!

Answer 1

just review your formulas. In particular,

h_i/h_o = f/f-d_o

32mm/17m = 40mm/(40-d_o)mm

32/17000 = 40/(40-d_o)
d_o = 21210mm = 21.21m