The first lens produces an image
at I1 Since image I1 is real, it serves as a virtual
object for the second lens B, producing the final
image at I It must, however, be borne in mind that
formation of image by the first lens is presumed
only to facilitate determination of the position of the
final image In fact, the direction of rays emerging
from the first lens gets modified in accordance with
the angle at which they strike the second lens