John Rudiak is right. Point source and collimated light are different. At
close range a point source is very uncollimated, the rays strike at a quite
oblique angle, though it is not diffused. However, if you move the point
source further away, say a few light years,. the rays would appear to be
parallel. Sunlight is for all practical purposes is collimated, though not
a point source. An airplanes shadow is the same size as the plane but the
shadow disappears when the plane is very high in the air, this is due to
the fact that from the ground the relative size of the plane is smaller
than the sun. It is like a fly on a lightbulb, the fly will cast no shadow
on the opposite wall.
Dick