If you are casting a shadow of a ball on the wall, how do you make the umbra larger than the ball or is it impossible. Also, how can you make the umbra smaller than the ball or is it impossible? How can you make the radius of the penumbra larger than the balls radius? How can you make the radius of the penumbra smaller than the ball radius?
I know the umbra is the really dark portion where all of light is blocked, but I don't know how to adjust it
put the ball next to the light, the umbrella gets large.
smaller? move the ball close to the sceen.
radius large? see the first answer above.
smaller? move the ball toward the screen, or make the light larger diameter.
https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcTUujzi6CXKwSzRPDb2VvkGj7Tzly32RzQcIlGFWAOAyBjMxYjqXw
on the radius larger, look at that figure....can the umbra ever be bigger than the radius of the object?
Thank you!
https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSQy7OK33WvT0CrizFuRWBeatqSGvdgsmkksVHOlrIpDRiXNUMmFQ
To make the umbra larger than the ball's size, you need to increase the distance between the ball and the light source. The closer the light source is to the ball, the smaller the umbra will be. By moving the light source farther away from the ball, you can make the shadow cast by the ball larger than the ball itself, resulting in a larger umbra.
Conversely, to make the umbra smaller than the ball's size, you need to bring the light source closer to the ball. By positioning the light source closer to the ball, the size of the shadow cast by the ball will be reduced, resulting in a smaller umbra.
Now, let's talk about the penumbra. The penumbra is the region surrounding the umbra where partial light is blocked, resulting in a gradual transition from full shadow to partial shade. Unlike the umbra, which can be adjusted by changing the distance between the light source and the object, the size of the penumbra is primarily determined by the size of the light source itself.
To make the radius of the penumbra larger than the ball's radius, you need to use a larger light source. A bigger light source will create a wider cone of light, resulting in a larger penumbra. You can achieve this by using a larger lamp or by adding diffusers to the light source to spread the light.
Conversely, to make the radius of the penumbra smaller than the ball's radius, you need to use a smaller light source. A smaller light source will create a narrower cone of light, resulting in a smaller penumbra. You can achieve this by using a smaller lamp or by using a narrower light beam.
It's important to note that the shape and size of shadows and their components like umbra and penumbra can also be influenced by factors such as the shape of the object, other light sources in the area, and the characteristics of the surface on which the shadow is cast.