Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What mechanical device controls the duration that the film or CCD in the camera is exposed to light?

1. Lens

2. Shutter

3. Aperture

4. Viewfinder

The correct answer is: Shutter

The shutter is the mechanical device responsible for controlling the duration that the film or CCD (Charge-Coupled Device) in a camera is exposed to light. It essentially acts as a gate, opening and closing to allow light to hit the film or sensor for a specific period. This duration is known as the exposure time, and it plays a critical role in determining how light or dark an image will be. A longer exposure allows more light in, which is useful in low-light conditions, while a shorter exposure can prevent overexposure in brighter environments. In contrast, the lens focuses the light onto the film or CCD but does not regulate its duration of exposure. The aperture, which is an opening within the lens, controls the amount of light that enters the camera by adjusting its size, but it does not determine how long the light is allowed to reach the sensor. The viewfinder serves as a tool for composing and framing the photograph, providing a preview of the scene but without any influence on exposure duration. Thus, the shutter is the key component that dictates how long the film or CCD is exposed to light, making it the correct answer.