Final answer:
A camera with a lens that has a preset focal length that focuses well on objects within a specific distance is known as a fixed-focus camera. These cameras can't adjust for different distances outside of their preset range, unlike autofocus or optical zoom cameras, which have adjustable lenses for varying focusing requirements.
"the correct option is approximately option C"
Step-by-step explanation:
The type of camera that has a lens with a preset focal length that focuses well on objects within a specific distance is a fixed-focus camera. Fixed-focus cameras are designed to have a set focal range and are unable to adjust to different distances beyond this range. This type of camera is contrasted with autofocus cameras, which can adjust the lens to focus on objects at various distances, and optical zoom cameras, which can change the focal length to bring distant objects into clearer view.
When you focus a camera that acts like a thin lens, you are adjusting the distance between the lens and the film (or sensor in digital cameras) to achieve a clear image. However, this lens cannot be kept at a fixed distance from the film for both near and distant objects because the focal point for different object distances will fall at different places. Specifically, to focus on distant objects, you would need to adjust either the lens or the image sensor to ensure that the light converges at the correct point to produce a sharp image. Fixed-focus lenses lack this adjustability, making them less versatile than their counterparts.
Simple magnifiers, like those used in smartphone cameras, show how fixed-focus systems use a lens with a predetermined focal length to focus light onto the image sensor. Unfortunately, without the ability to move the lens or sensor, a fixed-focus lens can only produce clear images of objects within a certain range of distances. Objects outside of this range will appear blurry because the lens cannot accommodate their focal points.