Question

The focal length of your camera lens is 70mm. It is used for taking pictures of your friend who is 1.5m tall. What is your friends distance from the lens if the image just fills the 24mm vertical dimension of the film?

I tried M=hi/ho=.16
.16=di-f/f di=-68.88

Answer 1

Careful. 1.5 m is 15000 mm.

Answer 2

.016=di-f/f = 71.12
.016=-di/d0 =4.445m

1.5m=1500mm