21 Nov 2000  Experiments with Polarised Light

A piece of cellophane paper

Audio cassette case

CD jewel case

Linex drawing curves

Crumpled cellophane paper

Thin mica washers, as used for insulating power transistors

The technique for taking these photographs is first to re-mortgage your house and buy a sheet of polarising film, which is illuminated from behind via a diffusion sheet.  The camera lens has a polarising filter fitted which is rotated until it is at right angles to the sheet, so the viewfinder looks dark (the digital camera does not have a filter thread on the lens, so to take these I just held the filter in front of it).  The object to be photographed is placed between the polarisers.  All you have to do then is find some things to photograph - plastic works well, as does cellophane paper of the type usually used for wrapping foodstuffs.  Thin sheets of mica, if you can find some, can produce some spectacular effects.  The correct exposure seemed to be about one stop less than indicated by the camera's metering.