A type of photography that I have become fond of in the last few years is refractographs. These images are created using a camera without a lens on the front of it. First you need a really dark room since any stray light can muddy up the image. Next you need a piece of glass or some other transparent material. In my experience thin, high quality glass works best. I have been using the bottom of crystal wine glasses. The glass is fixed in place with a light stand and clamp or something similar. Then a small bright point of light is set up about ten feet away from the glass with the light shining on the glass at about a forty five degree angle. I am using a bright LED flashlight with a piece of aluminum foil over the front of the light. I poke a very small hole in the foil with a needle. Do not use a laser since it could damage the camera sensor. Finally the camera is placed on a tripod very close to the glass.
If you turn off all the lights except the flashlight and turn on live view on the camera you will see a pattern of light appear on the image sensor. The light from the flashlight is refracted through the front of the glass, part of the light is then reflected off the rear surface of the glass then refracted again as it bounces toward the camera. It takes a lot of experimentation with position of the glass and the camera to find interesting patterns. Since there is not very much light the exposure will typically be fairly long. Most of the time I end up between two and six seconds. These patterns will initially be white. In order to get color into the images I take small pieces of colored plastic, called gel filters, from my macro flash heads and hold them in front of the camera between the glass and the sensor.
The images created can be very striking. There is also a bit of a treasure hunt quality to the process since you never can tell what kind of pattern any given piece of glass will create.