If the central portion of a convex lens is wrapped in black paper as shown in figure

How wil the image formed by a convex lens be affected, if the central portion of the lens is wrapped in black paper, as shown in the figure.

If the top half of a convex lens is covered with black paper

Half of the lens is wrapped in black paper How will it change the image?

A convex lens is a diverging lens.

A lens having focal length f and aperture of diameter d//2 in the central region of the lens is covered by a black paper.Focal length of the lens and intensity of image image now will be respectively

Concave lens and convex lens