Question

4) How does the imaging process work in a pinhole camera? How is it different from the imaging process for a system equipped with a lens?

5) What is the difference between a wide angle and a telephoto lens? What image differences do they produce?

Answer 1

2.

TELE-PHOTO
tele means distant or far-off or away,

like tele in tele-scope, tele-gram, tele-vision, tele-graph.
in some way or the other all these tele- prefixed words are related to transmitting/receiving things from a farther distance.

or in simple words if you want to take photographs of birds, wild animals, or a cricketer/baseball player, or moon surface without going near to any of them, you need a telephoto lens, usually they have a larger focal length value around 200-800 mm.

WIDE-ANGLE
wide angle means covering a bigger/larger area,
the wide angle lens allows more of the scene to be included in the photo.
it is usually useful in architectural, interior and landscape photography where the photographer may not be able to move farther from the scene to photograph it.

in simple words the smaller the focal length of the lens the wider or bigger will be the surface area covered by the lens, and sometimes if the field of view becomes wide-wide like crazy wide it is referred as a fish-eye lens.

4.

Pin hole camera

A pinhole camera is the simplest camera possible. It consists of a light-proof box, some sort of film and a pinhole. The pinhole is simply an extremely small hole like you would make with the tip of a pin in a piece of thick aluminum foil.

A pinhole camera works on a simple principle. Imagine you are inside a large, dark, room-sized box containing a pinhole. Imagine that outside the room is a friend with a flashlight, and he is shining the flashlight at different angles through the pinhole. When you look at the wall opposite the pinhole, what you will see is a small dot created by the flashlight's beam shining through the pinhole. The small dot will move as your friend moves his flashlight. The smaller the pinhole (within limits), the smaller and sharper the point of light that the flashlight creates.

Camera with lense

The distance from the lens to the image is the image distance, often labeled qq or didi. If it's positive, there is a real image and that is where the film or sensor should be.

A pinhole camera doesn't have a lens. It has a focal length of ??. This leads to a virtual image (negative qq), but the pinhole gives it such a huge depth of field that you call place the film anywhere and get focus as if you had a real image.