Question
A 17.1 cm focal-length lens is used to project 35 mm slides onto a screen 4.77 m from the projector lens. What must be the width of the screen ( m) if the image of the slide is to just fill the screen? The width of the image on the slide is 34.3 mm.
Answers
drwls
Get the distance from lens to slide , do, by using the equation
1/di + 1/do = 1/f
where f = 17.1 cm and image distance di = 477 cm
I get 1/do = 0.05638
do = 17.7 cm
The magnification is di/do = 477/17.7 = 27.0
27 times the slide picture width is 924 mm or 0.924 meter
That is how wide the screen must be.
1/di + 1/do = 1/f
where f = 17.1 cm and image distance di = 477 cm
I get 1/do = 0.05638
do = 17.7 cm
The magnification is di/do = 477/17.7 = 27.0
27 times the slide picture width is 924 mm or 0.924 meter
That is how wide the screen must be.