I have seen this displayed best when it is Christmas. Many photographers cover their lenses with black construction paper with a very small shape cut out to change the shape of the distorted light. As a matter of fact my new sister in law tried this last Christmas with a small heart shape and it turned out very well. I thought I would try myself with some shapes that were a little unconventional. I also thought that I would show what happens when the camera is still and also when it is not set on a tripod. Any slight movement when you are trying to distort the light will give very different and sometimes radical results.
This was the first pic I took with a cut out of the typical cherry emblem. For this one I just blurred the entire picture.
This was an arrow which actually showed up pretty well. However, you can see what just a slight hand movement can create.
Now this was still the cherries but I was moving my arm in circular motions to show what can happen with rapid movement.
This was also the cherry emblem.
This was again the cherry emblem but with slight movement as my hands love to shake. I put it on here because it reminds me of those great paintings with the stick like figures that would always be playing the saxaphone. :-)