The contact point in which the shadow touches the object is way sharper than say 5 metres from the object that’s casting a shadow. How come?
In: Physics
the size and shape of the light source is a contributor to this effect. with a very fine ‘point’ source, all of the light is traveling roughly in the same direction as it passes the edge of the object, casting a sharper shadow (hard), even over longer distances. with a larger bulb, or series of LEDs (and especially multiple light sources), light is arriving at the edge of an object with slightly more variation in direction. the effect of these variations is small at short range, but contributes to blurry (soft) shadows as distance increases.
imagine if you were to point 2 laser pointers in as close to the same direction as possible before turning them on. a wall 5 feet away would not show much separation between the two light points, however, pointing them at a barn 100 feet away would yield a much wider separation.
Latest Answers