Question

1. when using a film camera, what must you do to bring an object into focus? (1 point) close the diaphragm. move the lens toward or away from the film. adjust the speed of the shutter. adjust the angle of the mirror

Explanation:

In a film camera, the principle of focusing is based on the lens - film distance. The diaphragm controls the amount of light entering (related to aperture), the shutter speed controls the exposure time (related to how long light hits the film), and the mirror (in some cameras like SLRs) is mainly for the optical viewfinder mechanism. To bring an object into focus (make the image sharp on the film), we use the lens formula \(\frac{1}{f}=\frac{1}{u}+\frac{1}{v}\) (where \(f\) is the focal length of the lens, \(u\) is the object distance, and \(v\) is the image distance). When the object distance \(u\) changes, we need to change the image distance \(v\) (lens - film distance) to satisfy the lens formula for a sharp image.

Answer:

Move the lens toward or away from the film.