The coma maker is a piece of apparatus which focuses light through three grids of 2mm slits onto a projection surface.

The main element is the water lense which can be tilted via a gyroscope mechanism to any angle relative to the light source. The tilting of the lense in relation to the light creates a focusing aberration called a coma.

The name coma comes from the use of parabolic mirrors in telescopes which cause an aberration that stretches the image of a star to make it appear like a comet. See the diagram below.

More information on this project is described on the research page 'Light as Material'

materials: water, clear 5mm acrylic (laser cut) , threaded rod, vacuum formed PET, 15mm steel strip, laser cut foamboard.

Some images of the making process: