What is the imaging principle of camera, camera and magnifying glass?

The camera uses a convex lens u >；; 2f。 Make a miniature inverted image (if you think so, the camera is so much smaller than people that you can never make an enlarged image. Then push it according to the theory, and you will know that it is using u & gt2f's law)

The projector uses a convex lens 2f >:u>；; F becomes an enlarged inverted image. In this way, the image formed by the slide projector is larger than the negative and can be seen on the screen, indicating that it is an enlarged real image. Then press this button, and you will know at once)

Magnifier uses convex lens u

(u is the object distance f is the focal length)