Pinhole camera
If you replace the lens with a pinhole, you get a pinhole camera. The method it works by is that instead of bending the light rays so they hit the correct spot to form an image on the sensor the pinhole will only pass light rays that come from the correct direction. This means that almost all light is blocked from entering the camera and long exposure times must be used.
Pictures taken with a pinhole camera is usually not very sharp because of the size of the pinhole must be of a certain minimum size otherwise diffraction will blur the picture even more. Some of the advantages is that there are no geometrical distortions of the picture, the Depth of field is extreme and the pinhole will pass all types of light from ultraviolet to infrared.
