Table of Contents
Introduction
Polarised light photography can reveal some surprising results. Polarised light can be produced in a number of ways, including when light is reflected from some surfaces, emitted by screens on devices like laptops or by passing through filters made from particular materials, for example Polaroid sunglasses. In normal daily life, you will not be able to notice whether the light entering your eye is polarised or not. However, in this post, you can explore the creative possibilities of using polarised light to reveal the truly secret colours of plastic. Let’s look how to do this!
What you need
- A screen to act as a light source. This could be a mobile phone, tablet or laptop screen
- Polaroid sunglasses, Polaroid 3-D movie glasses or a polarising filter for a camera
- A selection of transparent plastic objects such as food boxes, a ruler, plastic cutlery or transparent plastic bag like a food bag
- Finally a person to help hold things or a tripod to mount the camera on
What to Do
Using Glasses
Set up the light source screen so that it is mainly white for example by displaying a blank window with a word processor on a laptop. Hold the glasses in front of the screen.
Rotate the glasses and look for an orientation where light from the screen is dimmed or blocked completely.
Using a filter
Set up the light source screen so that it is mainly white for example by displaying a blank window with a word processor on a laptop. Hold the filter in front of the screen or attach it to your camera
Rotate the filter and look for an orientation where light from the screen is dimmed with a blue tint.
Adding some plastic
Without changing the orientation of the glasses or the filter place some transparent plastic in between the screen and the glasses/filter. You should see coloured patterns due to stress in the plastic from its manufacture.
If you use the transparent plastic bag, cut it into a single layer and then stretch and pull it. Place it between the screen and the glasses/filter and stretch it some more. You should see the coloured patterns change as you pull on the plastic.
Gallery
Become a ‘stress detective’ and investigate transparent plastic materials and objects. Here are some more examples of what you might see.
Wrapping Up
I used to teach this effect as part of a physics course. It was one of those lessons that students couldn’t get enough of. Who says physics is boring! I hope you enjoy exploring photography with polarised light as much as I, and my students, did. This video has more examples and an explanation of the effect.
Polarised Light Photography FAQ
Polarised light is light with particular optical properties (not normally visible to the naked eye) formed when light is reflected from some surfaces, emitted by some screens on devices like laptops, or by passing through filters made from particular materials, for example, Polaroid sunglasses.
The plastic must be transparent and it also has to be stressed. Most manufactured transparent plastic objects are stressed during the production process so they will always show the patterns shown here.
Yes, if you use a transparent plastic bag, then you will definitely see the patterns shown in this post if you stretch and cut the plastic material.
No, any camera is suitable including a mobile phone camera. Also, you can just view the patterns with your naked eye.
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