Question

A 35 mm camera has a picture size of 24 mm by 36 mm. It is used to take a picture of a person 186 cm tall so that the image just fills the height (24 mm) of the film. How far should the person stand from the camera if the focal length of the lens is 40 mm ?

Answer 1

To find the distance the person should stand from the camera, use the thin lens equation.

Step-by-step explanation:

To find out how far the person should stand from the camera, we can use the thin lens equation, which states that 1/f = 1/di + 1/do, where f is the focal length, di is the image distance, and do is the object distance.

Here, the focal length (f) is 40 mm, and the image distance (di) is the height of the film, which is given as 24 mm. We need to calculate the object distance (do) which is the height of the person.

Using the equation, 1/40 = 1/24 + 1/do. Solving for do, we find that the object distance is approximately 89.33 mm.

Therefore, the person should stand approximately 89.33 mm or 8.93 cm away from the camera for the image to just fill the height of the film.