I have been trying to understand the science behind cameras and photography. I started with "camera obscura" and understood that * when rays of light are passed through a small hole (aperture) of a dark room (or box), the rays get inverted (upside down) and thus produces an inverted image
My understanding is that in most cameras there is a lens followed by the aperture, which is then followed by the image sensor (CMOS or CCD).
----rays-of-light--> || || ||
Lens Aperture CMOS
If I am right, focal length is the distance between lens and convergence-point of the light on CMOS.
"Focal length also affects the kind of image your camera captures, as well. A very short focal length will allow a photographer to capture a wider field of view, while a very long focal length (say, a telephoto lens) will cut the area you’re imaging down to a much smaller window."
How does the focal length help in capturing wider or narrower picture ?