A real image of a point object located on the principal axis is...

When the upper half of a convex lens is coated black, the lower half of the lens remains uncovered and continues to refract the light rays from the object to form the complete image.

Since the focal length and the position of the lens remain unchanged, the position of the image is unaffected according to the lens formula $\dfrac{1}{v} - \dfrac{1}{u} = \dfrac{1}{f}$. Thus, the image does not shift.

However, the amount of light passing through the lens is reduced to half. As a result, the intensity or brightness of the image decreases.