What happens to the amount of light reaching the film when the shutter speed is advanced from 1/50 to 1/100 second?

When the shutter speed is advanced from 1/50 to 1/100 second, the amount of light reaching the film is reduced by one-half. This is because a faster shutter speed means that the shutter opens and closes more quickly, allowing less time for light to enter the camera and reach the film.

The key concept here is that shutter speed operates on a reciprocal scale, where each doubling of the shutter speed results in a halving of the light that is captured. Therefore, moving from 1/50 to 1/100 seconds means the exposure time is halved, and thus half the amount of light will reach the film compared to when the shutter speed was set to 1/50 second.

This principle is essential in photography, as it affects exposure and image brightness. When photographers adjust the shutter speed, they must often compensate by adjusting other settings, such as aperture or ISO, to maintain proper exposure levels.