Thursday 22 November we had a workshop on `Photography using Cross Polarisation organised by Michele Emslie. As you can see this involves using an LCD screen as the light source. This emits polarised light, in other words the light generated by the screen comes out in a narrow angle. We all had polarising filters on our cameras and by rotating these we can block most of the light from the screen so it appears black or a dark magenta (Apple Retina screens).
If we then put a transparent object in front of the screen that has some degree of polarising capability (because of internal stress or molecular structure) the polarised light gets rotated and not blocked anymore by the polarising filter on the camera. Clear plastic things like cups, cutlery, CD case, safety specs all do this to varying degrees, as you can see from the images captured on the night. The different colours are related to the thickness and the stress in the plastic, the light gets rotated more when the plastic is thicker, as it has to travel a longer path.
A few images of club members in action, we had to turn the lights off in the room to avoid reflections and spoiling the colours, hence it was a bit dark apart from the laptops lighting up the room.
We all enjoyed this evening and since this is easy to do once you know how, I’m hoping to see more of these images from our Visionaires. Many thanks to Michele Emslie for organising the evening.