# Covering half of a lens [duplicate]

What happens to the image of an object kept before a lens if the upper half of lens is covered by an opaque coating?

I understand that the full image will be formed and only the intensity of the image is reduced. But is the intensity uniformly reduced? That is, will the upper and lower half of image have same intensity?

(The object is kept at a distance $1.25f$ before the lens. Half the object is above the principle axis. $f$ is the focal length of lens).

## marked as duplicate by John Rennie, Kyle Kanos, user36790, AccidentalFourierTransform, GertApr 10 '16 at 0:25

• Possible duplicate of A half covered lens – John Rennie Apr 7 '16 at 11:07
• @JohnRennie I am asking about the distribution of intensity. The answer given says that upper half of image is brighter. Is it a mistake? – Aditya Dev Apr 7 '16 at 11:24