What is the exact definition of a real/virtual image? This is what gave rise to the doubt. Suppose we have a pair of plane mirrors inclined at any angle. A point object lies on the angle bisector of the two mirrors. Now,the object sends out 2 rays,one towards each mirror. These will intersect at a point on the angle bisector after reflection from the mirrors. Is this a real image? If we follow this, we will find that the whole space is filled with such "images" of the object. But I feel something's wrong here. If we say that all rays emitted by one point of an object should meet at a single point for the image to be real, do we also imply that the image should have an intensity comparable to the object?