Light Canvas
Start
Index
Subtitle
01
Let's Make a Light Canvas
Subtitle
02
How Does it Work?
03
A Bit of History
04
Polarisation in Nature
05
Interesting Uses
06
More Fun Stuff
Let's Make a Light Canvas
01
Step 1
Polarising filters
Clear acetate sheets
Transparent tape
Floating frame with base
Get your materials
Set up near a bright doorway or window so that you have plenty of light to work with. Here are the required materials from your TinkerTime kit:
- A clear acetate sheet
- Some transparent tape
- Two polarising filters
- A mounting frame with base
In addition, you will need a pair of scissors. The tape and the grey polarising sheets may look ordinary, but they have a hidden optical property that will soon turn invisible light into bursts of colour!
Step 3
Subtitle
Assemble your pattern
Time to get creative! 1. Place your acetate sheet on the table or any flat surface. 2. From the transparent tape, cut out small pieces using scissors. Try not to smudge the tape with your fingerprints. Stick the cut pieces on the acetate sheet in any pattern you want. 3. You can try geometric shapes, lines, criss-crossing stripes, random strips or anything you fancy. 4. Cut off any excess tape that hangs outside the acetate sheet's boundaries. You won’t see colours yet. But your arrangement will change how light will twist, when it passes through your pattern.
Step 3
Assemble your pattern
Time to get creative! 1. Place your acetate sheet on the table or any flat surface. 2. From the transparent tape, cut out small pieces using scissors. Try not to smudge the tape with your fingerprints. Stick the cut pieces on the acetate sheet in any pattern you want. 3. You can try geometric shapes, lines, criss-crossing stripes, random strips or anything you fancy. 4. Cut off any excess tape that hangs outside the acetate sheet's boundaries. You won’t see colours yet. But your arrangement will change how light will twist, when it passes through your pattern.
Clear tape on acetate, in different patterns
Step 2
Two polarising films, rotated against each other
Check your filters
The grey plastic sheets in your kit are called polarising sheets or filters or polarising films. Hold the two polarising sheets at 1-2 feet from you. Place them one behind the other. Now slowly rotate one of them. You would see the light through the sheets go from bright to almost completely dark. You can also hold a sheet (just one) against your computer screen and rotate it slowly. That part of the screen too would go from light to completely dark. This tells you the filters are working. You can also use this test to check if your sunglasses are real or fake!
One polarising film, rotated against a laptop screen
Step 4
Mount your artwork
Your optical art is now ready to be displayed... Your art is now ready to be backlit. There are two ways to do this: 1. With natural light or 2. With Laptop screen's light. For 1: Open your floating frame where it's marked 'Press'. Place one polarising film in the frame. Now place the acetate sheet with the tape side touching the film. Close the frame. For 2: Open your floating frame. Place the patterned acetate sheet inside, with the tape side facing away from you. Close the frame. We are using the frame because it keeps the artwork flat while allowing light to pass through from behind. You can now mount the closed frame on its base.
Acetate with tape pattern, mounted against bright window
Step 4
Mount your artwork
Your optical art is now ready to be displayed... Your art is now ready to be backlit. There are two ways to do this: 1. With natural light or 2. With Laptop screen's light. For 1: Open your floating frame where it's marked 'Press'. Place one polarising film in the frame. Now place the acetate sheet with the tape side touching the film. Close the frame. For 2: Open your floating frame. Place the patterned acetate sheet inside, with the tape side facing away from you. Close the frame. We are using the frame because it keeps the artwork flat while allowing light to pass through from behind. You can now mount the closed frame on its base.
Acetate with tape pattern, mounted against bright window
Step 5
The pattern becomes colourful when seen with a polarising filter
Make it come alive
Get ready for some mesmerising magic. Place the mounted frame against your light source (bright window or laptop screen), so that light can enter your frame. If you are using a laptop, increase the screen's brightness to the maximum setting. View the frame through a polarising film (in case of natural light, it will be the other remaining filter). Do you see that the pattern turned colourful? Now gently rotate the filter in your hand. Watch how the colours change and parts of the pattern appear and disappear. What looked like simple tape now behaves like a dynamic painting made from light!
The same pattern, when viewed against a bright laptop screen
Step 6
Experiment with different number of tape layers and directions to find out which combinations you like most
Make it more colourful
These factors will determine how intense and colourful your pattern will turn out... Number of layers - If your pattern has pieces of tape overlapping in some places, the colours will be different in those places. And the colours change based on the number of layers you add. Direction - Instead of having the tapes in just one direction, make a pattern where you'd need to align different pieces in different directions. (Eg., some pieces vertical, some horizontal, some at 45 degrees, some at random angles, etc) Thickness of the tape - if you have a thicker/thinner tape at home, you can try bits of that too.
Step 7
Showcase your art
We would love to display your light canvas in the TinkerTime virtual gallery... Take a photo or short video of your Light Canvas while rotating the filters. Capture the colours shifting — that movement is part of the artwork!
Upload photo/ video clip
Let's Make a Light Canvas
01
Step 1
Get your materials
Polarising filters
Clear acetate sheets
Transparent tape
Floating frame with base
Set up near a bright doorway or window so that you have plenty of light to work with. Here are the required materials from your TinkerTime kit:
- Two polarising filters
- A clear acetate sheet
- Some transparent tape
- A floating frame with base
In addition, you will need a pair of scissors. The tape and the grey plastic sheets may look ordinary, but they have a hidden optical property that will soon turn invisible light into bursts of colour!
Step 3
Get your materials
Time to get creative! 1. Place your acetate sheet on the table or any flat surface. 2. From the transparent tape, cut out small pieces using scissors. Try not to smudge the tape with your fingerprints. Stick the cut pieces on the acetate sheet in any pattern you want. 3. You can try geometric shapes, lines, criss-crossing stripes, random strips or anything you fancy. 4. Cut off any excess tape that hangs outside the acetate sheet's boundaries. You won’t see colours yet. But your arrangement will change how light will twist, when it passes through your pattern.
Gently dab with a paper tissue to remove excess water without disturbing the pattern.
Step 4
Mount your artwork
Your light collage is now ready to be displayed... Just like we did in Type 1, there are two ways to display your collage: 1. With natural light or 2. With Laptop screen's light. For natural light: Place one polarising film in the frame, on top of the assembled collage elements. Close the frame and mount it on its base. Place the mounted frame against a bright window or in a place where you can see bright natural light through it. Make sure the polarising film is on the side facing the light. That is, away from you.
Acetate with tape pattern, mounted against bright window
Step 4
Mount your artwork
Your optical art is now ready to be displayed... Your art is now ready to be backlit. There are two ways to do this: 1. With natural light or 2. With Laptop screen's light. For 1: Open your floating frame where it's marked 'Press'. Place one polarising film in the frame. Now place the acetate sheet with the tape side touching the film. Close the frame. For 2: Open your floating frame. Place the patterned acetate sheet inside, with the tape side facing away from you. Close the frame. We are using the frame because it keeps the artwork flat while allowing light to pass through from behind. You can now mount the closed frame on its base.
Acetate with tape pattern, mounted against bright window
Step 5
The pattern becomes colourful when seen with a polarising filter
Make it come alive
Get ready for some mesmerising magic. Place the mounted frame against your light source (bright window or laptop screen), so that light can enter your frame. If you are using a laptop, increase the screen's brightness to the maximum setting. View the frame through a polarising film (in case of natural light, it will be the other remaining filter). Do you see that the pattern turned colourful? Now gently rotate the filter in your hand. Watch how the colours change and parts of the pattern appear and disappear. What looked like simple tape now behaves like a dynamic painting made from light!
The pattern becomes colourful when seen with a polarising filter
Some inspiration for your next Light Canvas
Step 7
Showcase your art
We would love to display your light canvas in the TinkerTime virtual gallery... Take a photo or short video of your Light Canvas while rotating the filters. Capture the colours shifting — that movement is part of the artwork!
Upload photo/ video clip
How does it work?
02
What is light?
Is light a ray? Or wave? Or particles?
Of course, light is also other things... Sometimes light is described as waves. But other times, it is also described as rays. Or as particles. And all of them are true.. For today's activity though, we are focusing mostly on its wave behaviour.
Light is a form of energy that can travel through space. Listen to this classic explanation of what light is, from Richard Feynman (a Nobel laureate who could explain complex things in very simple language).
Let's start here: Someone has jumped into a pool...
Richard Feyman explaining what light is
What is polarised light?
Normal light 'wiggles' in many directions When light energy travels, it doesn’t stay steady — it wiggles while moving forward. These wiggles can happen in many directions at the same time. Upward and downward, Sideways.. and in many other ways possible! Which is why light normally looks the same from every angle. This kind of light is called unpolarised light.
When most of those wiggles are restricted to one direction, the light is called polarised. You can think that polarised light is light that prefers to wiggle mostly in one direction.
This video has a great explanation for what polarised light is and how polarising films work
Polarising Films - how do they work?
Most of us humans cannot see the difference between polarised light and unpolarised light with our naked eyes. We need special materials called polarisers, which make the difference visible to us.
In case the previous video was a bit difficult to understand, here's a simpler analogy. (Analogy is a way of explaining something new,using another thing that you already know. It may not always be technically accurate. But it helps build an intuitive understanding). In this video, a photographer explains and shows how polarising films restrict the wiggles of light to one direction.
Cross-polarised filters
Remember how you checked your polarising films?
When two polarising filters are placed on top of each other, they can either pass light or block it, depending on their orientation.
If both filters are placed in the same direction, light passes through easily.
But if one filter is rotated 90° relative to the other, the second filter blocks the light from the first and the view becomes dark. In this case, we call them cross-polarised.
Birefringent materials
Many household objects contain transparent plastics or crystals that are stretched or stressed during manufacturing. Such materials often become birefringent. For e.g., clear tape is made by stretching a plastic film. This stretching causes its long polymer chains to line up in one direction, making it birefringent. Here are other TRANSPARENT PLASTIC materials you can test for birefringence: food container lids, ruler, protractor, spoons, water bottles, storage boxes, phone screen protector, safety goggles, etc.
The hero of today's story - clear tape
In most transparent materials (like glass or water), the internal structure is random and uniform. So, light passing through the materials undergoes the same experience in every direction. But in some special materials, different directions inside the material are not equivalent. Their internal structure is organised differently in different directions (for eg., when plastic is stretched). This creates two axes - a fast axis and a slow axis. The experience of light is different in both. This causes the light to split into two components that gradually get out of step with each other. This property is called birefringence, meaning “two refractive behaviours.”
Birefringent material in between cross-polarised filters
Now is when the magic happens. When light passing though a birefringent material gets split into two components that are out of step, the polarisation also gets changed. Different colours of light get out of step by different amounts, so each colour ends up with a slightly different polarisation. We cannot see this with our naked eyes, so we use polarising filters. When the changed light reaches the second polariser, some colours now match its direction and pass through, while others are blocked. That is why clear materials like tape suddenly produce bright colours when viewed between cross-polarised filters. What colours you see depends on things like how thick the tape is, number of layers, orientation of the tape (angle), etc.
Explore birefringence at home
Go around your house collecting a few different transparent plastic objects. Place the objects one-by-one between your two polarising films. Rotate one of the films and observe the appearance of the object. Do brilliant colours appear? Do the colours change when you rotate one of the filters?
A Bit of History
03
Discovery of Polarisation
Double Refraction In 1669, a Danish scientist named Rasmus Bartholin noticed something very strange while studying a crystal called calcite. When he looked at a line of text through the crystal, he didn’t see one image — he saw two! The crystal was splitting the light into two separate paths, a phenomenon now called double refraction. At the time, no one understood why this happened, but it was the first clue that light could behave differently depending on how it travelled through certain materials. This mysterious effect later helped scientists discover the idea of polarisation.
Double refraction in calcite
Discovery of Polarisation
Watching Palace Windows...
In 1808, French military officer and physicist Étienne-Louis Malus was observing sunlight reflecting off the Luxembourg Palace windows through a crystal. He found that rotating the crystal caused the light to change in intensity. He established that light reflected from certain surfaces becomes polarized. This discovery fundamentally changed the understanding of light. Proving that light could be polarized was critical for understanding its transverse wave nature (as we saw in a video earlier). Malus’ Law describes how the intensity of polarised light changes as the angle between two polarising filters changes.
Etienne-Louis Malus (1775 - 1812)
The Sun Stone
But the Vikings seem to have known it much earlier!
Long before scientists understood polarisation, some historians believe that Viking sailors (as early as circa 700 BC) may have used special crystals called sunstones to find the Sun’s direction on cloudy days. These crystals, possibly made of calcite (Iceland spar), react strongly to polarised light in the sky. By rotating the crystal and observing brightness changes, sailors could estimate where the Sun was, even if it was hidden behind clouds... super useful for navigation!
Iceland spar / Sun Stone / Calcite
Natural Polarisers
Calcite
After scientists discovered polarisation, they began looking for materials that could reveal or control it. Some natural crystals, such as calcite (Iceland spar), quartz and tourmaline interact strongly with polarised light. These crystals split light into two rays. They absorb one direction of light more than another, allowing scientists to study polarisation in the laboratory. But these natural polarisers were rare, fragile, and difficult to shape into useful optical devices. Because of these limitations, scientists began searching for ways to create artificial materials that could polarise light more easily and cheaply.
Quartz
Tourmaline
Edwin Land
A quest to reduce accidents caused by glare
In the 1930s, a young inventor named Edwin Land solved the problem. He discovered that stretched plastic sheets containing aligned molecules, after coating with iodine, could act as powerful polarising filters. Land used this idea to create relatively inexpensive polarising films and founded the company Polaroid. His invention first appeared in products like glare-reducing sunglasses and camera filters. Later, his work also led to the famous instant camera.
Creativity
"An essential aspect of creativity is not being afraid to fail"
EDWIN LAND
Research today
Scientists are still discovering new ways to control polarised light. They are designing ultra-thin polarising materials made from nanostructures only a few atoms thick. These could improve cameras, virtual-reality displays, and advanced microscopes.
Some animals, like the mantis shrimp, can even detect circularly polarised light — something humans cannot normally see. See more such examples in the next section. By studying such natural systems, scientists hope to build new sensors and imaging technologies.
Mantis shrimp
Polarisation in Nature
04
Rainbows
When sunlight enters a raindrop, it bends, reflects inside, and comes out again. During this journey, the light becomes partially polarised, especially in certain directions. That means the light in a rainbow is not just colourful — it also has a hidden directional pattern. Scientists use polarising filters to study how rainbows form and how light behaves inside water droplets. So a rainbow is not just beautiful — it’s also a natural demonstration of polarised light.
Bees and their polarisation compass
Sunlight is originally unpolarised. But when it passes through the atmosphere it gets scattered, and light in different parts of the sky gets polarised in different directions. For example, the light is polarised differently when you look near the Sun compared to 90° away from it. The same pattern persists even when the Sun is hidden behind clouds.
Bees can detect this polarisation pattern of the sky, because they have special cells in their eyes which are sensitive to different polarisation directions. Bees use this information like a compass to navigate and find their way back to their hive. This allows them to travel long distances and still return home. Bees also translate this information into a "waggle dance" to communicate the direction and distance of food sources to other bees.
Ants do that too...
Some ants, especially desert ants, use the polarisation of the sky to navigate. When they leave their nest to search for food, they keep track of direction using this invisible pattern. In addition to the polarization compass, ants may also use the sun itself, step count (yes!), landmarks, and in some contexts, the geomagnetic field. It’s like having a built-in GPS using multiple signals. Studies have shown that this system can be modeled to create low-power, accurate navigation sensors for robots.
Cuttle fish
Their skin contains structures that reflect light in specific polarisation patterns. They use this ability for camouflage and communication, sending signals that other cuttlefish can detect but predators may not notice. This gives them a kind of “hidden channel” of communication.
Cuttlefish can both see and produce polarised light. They have the most acute polarization vision among animals. Their eyes are also sensitive to polarisation, helping them distinguish objects even in dim or muddy water.
Octopus
Octopuses can detect polarised light even though they do not see colour the way humans do. This helps them spot prey and objects that might otherwise blend into the background. Polarisation can reveal contrast and patterns that normal vision might miss. Combined with their ability to change colour and texture, this makes them highly effective hunters. They are using a completely different way of “seeing” the world.
Interesting Uses of Polarisation
05
Sunglasses
Polarised sunglasses are designed to reduce glare, especially from flat surfaces like water or roads. Reflected light from these surfaces is often horizontally polarised, which can be very bright and uncomfortable. The sunglasses contain a vertical polarising filter that blocks this direction, allowing only certain polarisations through. This improves contrast and visibility, helping you see more clearly. That’s why, if they wear sunglasses, fishermen can see into water and drivers can see the road better.
You can test this for yourself. Observe objects in your house kept on or near shiny surfaces like tiles, kitchen counter or wnidow panes. Note their reflection on these surfaces. Now look at the reflections through one of the polarising filters. Rotate the filter slowly. Do you see the reflections almost disappear when the filter is in a specific angle?
3D movies
In 3D movies, two slightly different images are projected onto the screen — one for each eye. These images are polarised differently (often using circular polarisation, which is explained in the video). The special glasses you wear have filters which ensure that each eye sees only its intended image. Your brain combines these two images to create a sense of depth and makes it appear 3D. Without polarisation, both eyes would see both images, and the 3D effect would disappear.
Stress Tests
Engineers use polarised light to study stress inside materials like plastic or glass. When these materials are under stress, they become birefringent, just like your tape. Between crossed polarisers, this reveals colourful patterns showing where the stress is strongest. This indicates where the material is weakest. These tests helps engineers design safer structures, from bridges to airplane parts.
LCD screens
LCD screens (like the screens in your phones and laptops) rely on polarisation to control each pixel.
- Light from a backlight first passes through a polariser.
- Then the polarised light goes through a layer of liquid crystals. These crystals change their orientation when electricity is applied. This changes how they rotate the polarisation of light. A group of such tiny crystals corresponds to each pixel on your screen.
- A second polariser either allows the light through or blocks it, creating bright or dark pixels on your screen. By controlling millions of these pixels, the screen forms images.
That’s why your screen looked dark when viewed through your polarising film at certain angles.
Play video
Gemology
Gemologists use an instrument called polariscope. The polariscope comprises two filters placed in a "crossed" position. A gem is placed between them and rotated 360 degrees. By observing how the gemstone interacts with the polarised light, expert gemologists can tell which kind of stone it is and whether the gem is natural or synthetic. They can also identify specific minerals inside it and check if there are internal strain marks. This helps in deciding the value of the precious stones.
Gems like sapphire, tourmaline, or quartz go from light to dark four times (once every 90 degrees).
Gems like spinel, diamond, or glass remain dark throughout a 360 degree rotation.
Play video
Polarisation Microscopy
In a polarisation microscope, objects are viewed not only through lenses that magnify. They are at the same time placed between crossed polarising filters too. Birefringent parts in the material will exhibit beautiful colours that reveal information about the material’s internal structure, thickness, stress, etc. Geologists use this information to identify minerals and understand how rocks were formed. In biology, many structures inside living organisms are too transparent to see clearly under normal light. But polarised light reveals detailed information about such structures. For eg., collagen fibres. Chemists use polarised light to detect how molecules are shaped and arranged, especially when they are mirror images of each other and can't be easily distinguished otherwise.
Cholesterol crystals, photographed by the chemist Vance Williams
Did you notice the colourful images in all the title slides in this presentation? They were all taken with polarisation microscopes!
More Fun Stuff
06
Austine Wood Comarow's Kinetic Polages (Polarisation Collages)
Some inspiration for your next Light Canvas
Artist: Austine Wood Comarow She came up with the idea of Polage (Polarised Light Collage) in 1967 when her husband showed her that a crumpled piece of cellophane turns colourful when placed between polarising films. Check out her stunning portfolio on her website.
Micro photography
Peter Juzak's microphotography... See sulphur, vitamin C, urea, etc in a new light!
Artist or Scientist??
Carol Roullard's crystal landscapes... that is Vanilla btw :)
Sugar twists
Why sugar is called Dextrose!
Share your feedback for this activity
Why sugar is called Dextrose!
Exit
Lorem ipsum dolor
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua, sed do eiusmod.
- Lorem ipsum dolor sit amet.
- Consectetur adipiscing elit.
- Sed do eiusmod tempor incididunt ut.
- Labore et dolore magna aliqua.
a. Take 2-3 acetate sheets (of the same size as your drawing) b. Cover each of them with different number of layers of tape. c. Aligning them with your original drawing, trace different parts of your picture on these acetate sheets. These will form layers in your Polage. d. Now take a precision knife/craft knife (Ask a parent for help). Cut out some of the outlines in each of your acetate sheets.
Step 2
Choose / draw a picture on one of your remaining acetate sheets. It is useful to have wide outlines that are easy to cut out.
Step 1
Mount 1 or 2 of these acetate cutouts on your base. Place against a bright laptop screen. View through a slowly-rotating polarisation filter.. Isn't this magical!
Step 3
Lorem ipsum dolor
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua, sed do eiusmod.
- Lorem ipsum dolor sit amet.
- Consectetur adipiscing elit.
- Sed do eiusmod tempor incididunt ut.
- Labore et dolore magna aliqua.
Light Collage
Mathu Shalini
Created on March 15, 2026
Start designing with a free template
Discover more than 1500 professional designs like these:
View
Math Lesson Plan
View
Primary Unit Plan 2
View
Animated Chalkboard Learning Unit
View
Business Learning Unit
View
Corporate Signature Learning Unit
View
Code Training Unit
View
History Unit plan
Explore all templates
Transcript
Light Canvas
Start
Index
Subtitle
01
Let's Make a Light Canvas
Subtitle
02
How Does it Work?
03
A Bit of History
04
Polarisation in Nature
05
Interesting Uses
06
More Fun Stuff
Let's Make a Light Canvas
01
Step 1
Polarising filters
Clear acetate sheets
Transparent tape
Floating frame with base
Get your materials
Set up near a bright doorway or window so that you have plenty of light to work with. Here are the required materials from your TinkerTime kit:
- A clear acetate sheet
- Some transparent tape
- Two polarising filters
- A mounting frame with base
In addition, you will need a pair of scissors. The tape and the grey polarising sheets may look ordinary, but they have a hidden optical property that will soon turn invisible light into bursts of colour!Step 3
Subtitle
Assemble your pattern
Time to get creative! 1. Place your acetate sheet on the table or any flat surface. 2. From the transparent tape, cut out small pieces using scissors. Try not to smudge the tape with your fingerprints. Stick the cut pieces on the acetate sheet in any pattern you want. 3. You can try geometric shapes, lines, criss-crossing stripes, random strips or anything you fancy. 4. Cut off any excess tape that hangs outside the acetate sheet's boundaries. You won’t see colours yet. But your arrangement will change how light will twist, when it passes through your pattern.
Step 3
Assemble your pattern
Time to get creative! 1. Place your acetate sheet on the table or any flat surface. 2. From the transparent tape, cut out small pieces using scissors. Try not to smudge the tape with your fingerprints. Stick the cut pieces on the acetate sheet in any pattern you want. 3. You can try geometric shapes, lines, criss-crossing stripes, random strips or anything you fancy. 4. Cut off any excess tape that hangs outside the acetate sheet's boundaries. You won’t see colours yet. But your arrangement will change how light will twist, when it passes through your pattern.
Clear tape on acetate, in different patterns
Step 2
Two polarising films, rotated against each other
Check your filters
The grey plastic sheets in your kit are called polarising sheets or filters or polarising films. Hold the two polarising sheets at 1-2 feet from you. Place them one behind the other. Now slowly rotate one of them. You would see the light through the sheets go from bright to almost completely dark. You can also hold a sheet (just one) against your computer screen and rotate it slowly. That part of the screen too would go from light to completely dark. This tells you the filters are working. You can also use this test to check if your sunglasses are real or fake!
One polarising film, rotated against a laptop screen
Step 4
Mount your artwork
Your optical art is now ready to be displayed... Your art is now ready to be backlit. There are two ways to do this: 1. With natural light or 2. With Laptop screen's light. For 1: Open your floating frame where it's marked 'Press'. Place one polarising film in the frame. Now place the acetate sheet with the tape side touching the film. Close the frame. For 2: Open your floating frame. Place the patterned acetate sheet inside, with the tape side facing away from you. Close the frame. We are using the frame because it keeps the artwork flat while allowing light to pass through from behind. You can now mount the closed frame on its base.
Acetate with tape pattern, mounted against bright window
Step 4
Mount your artwork
Your optical art is now ready to be displayed... Your art is now ready to be backlit. There are two ways to do this: 1. With natural light or 2. With Laptop screen's light. For 1: Open your floating frame where it's marked 'Press'. Place one polarising film in the frame. Now place the acetate sheet with the tape side touching the film. Close the frame. For 2: Open your floating frame. Place the patterned acetate sheet inside, with the tape side facing away from you. Close the frame. We are using the frame because it keeps the artwork flat while allowing light to pass through from behind. You can now mount the closed frame on its base.
Acetate with tape pattern, mounted against bright window
Step 5
The pattern becomes colourful when seen with a polarising filter
Make it come alive
Get ready for some mesmerising magic. Place the mounted frame against your light source (bright window or laptop screen), so that light can enter your frame. If you are using a laptop, increase the screen's brightness to the maximum setting. View the frame through a polarising film (in case of natural light, it will be the other remaining filter). Do you see that the pattern turned colourful? Now gently rotate the filter in your hand. Watch how the colours change and parts of the pattern appear and disappear. What looked like simple tape now behaves like a dynamic painting made from light!
The same pattern, when viewed against a bright laptop screen
Step 6
Experiment with different number of tape layers and directions to find out which combinations you like most
Make it more colourful
These factors will determine how intense and colourful your pattern will turn out... Number of layers - If your pattern has pieces of tape overlapping in some places, the colours will be different in those places. And the colours change based on the number of layers you add. Direction - Instead of having the tapes in just one direction, make a pattern where you'd need to align different pieces in different directions. (Eg., some pieces vertical, some horizontal, some at 45 degrees, some at random angles, etc) Thickness of the tape - if you have a thicker/thinner tape at home, you can try bits of that too.
Step 7
Showcase your art
We would love to display your light canvas in the TinkerTime virtual gallery... Take a photo or short video of your Light Canvas while rotating the filters. Capture the colours shifting — that movement is part of the artwork!
Upload photo/ video clip
Let's Make a Light Canvas
01
Step 1
Get your materials
Polarising filters
Clear acetate sheets
Transparent tape
Floating frame with base
Set up near a bright doorway or window so that you have plenty of light to work with. Here are the required materials from your TinkerTime kit:
- Two polarising filters
- A clear acetate sheet
- Some transparent tape
- A floating frame with base
In addition, you will need a pair of scissors. The tape and the grey plastic sheets may look ordinary, but they have a hidden optical property that will soon turn invisible light into bursts of colour!Step 3
Get your materials
Time to get creative! 1. Place your acetate sheet on the table or any flat surface. 2. From the transparent tape, cut out small pieces using scissors. Try not to smudge the tape with your fingerprints. Stick the cut pieces on the acetate sheet in any pattern you want. 3. You can try geometric shapes, lines, criss-crossing stripes, random strips or anything you fancy. 4. Cut off any excess tape that hangs outside the acetate sheet's boundaries. You won’t see colours yet. But your arrangement will change how light will twist, when it passes through your pattern.
Gently dab with a paper tissue to remove excess water without disturbing the pattern.
Step 4
Mount your artwork
Your light collage is now ready to be displayed... Just like we did in Type 1, there are two ways to display your collage: 1. With natural light or 2. With Laptop screen's light. For natural light: Place one polarising film in the frame, on top of the assembled collage elements. Close the frame and mount it on its base. Place the mounted frame against a bright window or in a place where you can see bright natural light through it. Make sure the polarising film is on the side facing the light. That is, away from you.
Acetate with tape pattern, mounted against bright window
Step 4
Mount your artwork
Your optical art is now ready to be displayed... Your art is now ready to be backlit. There are two ways to do this: 1. With natural light or 2. With Laptop screen's light. For 1: Open your floating frame where it's marked 'Press'. Place one polarising film in the frame. Now place the acetate sheet with the tape side touching the film. Close the frame. For 2: Open your floating frame. Place the patterned acetate sheet inside, with the tape side facing away from you. Close the frame. We are using the frame because it keeps the artwork flat while allowing light to pass through from behind. You can now mount the closed frame on its base.
Acetate with tape pattern, mounted against bright window
Step 5
The pattern becomes colourful when seen with a polarising filter
Make it come alive
Get ready for some mesmerising magic. Place the mounted frame against your light source (bright window or laptop screen), so that light can enter your frame. If you are using a laptop, increase the screen's brightness to the maximum setting. View the frame through a polarising film (in case of natural light, it will be the other remaining filter). Do you see that the pattern turned colourful? Now gently rotate the filter in your hand. Watch how the colours change and parts of the pattern appear and disappear. What looked like simple tape now behaves like a dynamic painting made from light!
The pattern becomes colourful when seen with a polarising filter
Some inspiration for your next Light Canvas
Step 7
Showcase your art
We would love to display your light canvas in the TinkerTime virtual gallery... Take a photo or short video of your Light Canvas while rotating the filters. Capture the colours shifting — that movement is part of the artwork!
Upload photo/ video clip
How does it work?
02
What is light?
Is light a ray? Or wave? Or particles?
Of course, light is also other things... Sometimes light is described as waves. But other times, it is also described as rays. Or as particles. And all of them are true.. For today's activity though, we are focusing mostly on its wave behaviour.
Light is a form of energy that can travel through space. Listen to this classic explanation of what light is, from Richard Feynman (a Nobel laureate who could explain complex things in very simple language).
Let's start here: Someone has jumped into a pool...
Richard Feyman explaining what light is
What is polarised light?
Normal light 'wiggles' in many directions When light energy travels, it doesn’t stay steady — it wiggles while moving forward. These wiggles can happen in many directions at the same time. Upward and downward, Sideways.. and in many other ways possible! Which is why light normally looks the same from every angle. This kind of light is called unpolarised light.
When most of those wiggles are restricted to one direction, the light is called polarised. You can think that polarised light is light that prefers to wiggle mostly in one direction.
This video has a great explanation for what polarised light is and how polarising films work
Polarising Films - how do they work?
Most of us humans cannot see the difference between polarised light and unpolarised light with our naked eyes. We need special materials called polarisers, which make the difference visible to us.
In case the previous video was a bit difficult to understand, here's a simpler analogy. (Analogy is a way of explaining something new,using another thing that you already know. It may not always be technically accurate. But it helps build an intuitive understanding). In this video, a photographer explains and shows how polarising films restrict the wiggles of light to one direction.
Cross-polarised filters
Remember how you checked your polarising films?
When two polarising filters are placed on top of each other, they can either pass light or block it, depending on their orientation.
If both filters are placed in the same direction, light passes through easily.
But if one filter is rotated 90° relative to the other, the second filter blocks the light from the first and the view becomes dark. In this case, we call them cross-polarised.
Birefringent materials
Many household objects contain transparent plastics or crystals that are stretched or stressed during manufacturing. Such materials often become birefringent. For e.g., clear tape is made by stretching a plastic film. This stretching causes its long polymer chains to line up in one direction, making it birefringent. Here are other TRANSPARENT PLASTIC materials you can test for birefringence: food container lids, ruler, protractor, spoons, water bottles, storage boxes, phone screen protector, safety goggles, etc.
The hero of today's story - clear tape
In most transparent materials (like glass or water), the internal structure is random and uniform. So, light passing through the materials undergoes the same experience in every direction. But in some special materials, different directions inside the material are not equivalent. Their internal structure is organised differently in different directions (for eg., when plastic is stretched). This creates two axes - a fast axis and a slow axis. The experience of light is different in both. This causes the light to split into two components that gradually get out of step with each other. This property is called birefringence, meaning “two refractive behaviours.”
Birefringent material in between cross-polarised filters
Now is when the magic happens. When light passing though a birefringent material gets split into two components that are out of step, the polarisation also gets changed. Different colours of light get out of step by different amounts, so each colour ends up with a slightly different polarisation. We cannot see this with our naked eyes, so we use polarising filters. When the changed light reaches the second polariser, some colours now match its direction and pass through, while others are blocked. That is why clear materials like tape suddenly produce bright colours when viewed between cross-polarised filters. What colours you see depends on things like how thick the tape is, number of layers, orientation of the tape (angle), etc.
Explore birefringence at home
Go around your house collecting a few different transparent plastic objects. Place the objects one-by-one between your two polarising films. Rotate one of the films and observe the appearance of the object. Do brilliant colours appear? Do the colours change when you rotate one of the filters?
A Bit of History
03
Discovery of Polarisation
Double Refraction In 1669, a Danish scientist named Rasmus Bartholin noticed something very strange while studying a crystal called calcite. When he looked at a line of text through the crystal, he didn’t see one image — he saw two! The crystal was splitting the light into two separate paths, a phenomenon now called double refraction. At the time, no one understood why this happened, but it was the first clue that light could behave differently depending on how it travelled through certain materials. This mysterious effect later helped scientists discover the idea of polarisation.
Double refraction in calcite
Discovery of Polarisation
Watching Palace Windows...
In 1808, French military officer and physicist Étienne-Louis Malus was observing sunlight reflecting off the Luxembourg Palace windows through a crystal. He found that rotating the crystal caused the light to change in intensity. He established that light reflected from certain surfaces becomes polarized. This discovery fundamentally changed the understanding of light. Proving that light could be polarized was critical for understanding its transverse wave nature (as we saw in a video earlier). Malus’ Law describes how the intensity of polarised light changes as the angle between two polarising filters changes.
Etienne-Louis Malus (1775 - 1812)
The Sun Stone
But the Vikings seem to have known it much earlier!
Long before scientists understood polarisation, some historians believe that Viking sailors (as early as circa 700 BC) may have used special crystals called sunstones to find the Sun’s direction on cloudy days. These crystals, possibly made of calcite (Iceland spar), react strongly to polarised light in the sky. By rotating the crystal and observing brightness changes, sailors could estimate where the Sun was, even if it was hidden behind clouds... super useful for navigation!
Iceland spar / Sun Stone / Calcite
Natural Polarisers
Calcite
After scientists discovered polarisation, they began looking for materials that could reveal or control it. Some natural crystals, such as calcite (Iceland spar), quartz and tourmaline interact strongly with polarised light. These crystals split light into two rays. They absorb one direction of light more than another, allowing scientists to study polarisation in the laboratory. But these natural polarisers were rare, fragile, and difficult to shape into useful optical devices. Because of these limitations, scientists began searching for ways to create artificial materials that could polarise light more easily and cheaply.
Quartz
Tourmaline
Edwin Land
A quest to reduce accidents caused by glare
In the 1930s, a young inventor named Edwin Land solved the problem. He discovered that stretched plastic sheets containing aligned molecules, after coating with iodine, could act as powerful polarising filters. Land used this idea to create relatively inexpensive polarising films and founded the company Polaroid. His invention first appeared in products like glare-reducing sunglasses and camera filters. Later, his work also led to the famous instant camera.
Creativity
"An essential aspect of creativity is not being afraid to fail"
EDWIN LAND
Research today
Scientists are still discovering new ways to control polarised light. They are designing ultra-thin polarising materials made from nanostructures only a few atoms thick. These could improve cameras, virtual-reality displays, and advanced microscopes.
Some animals, like the mantis shrimp, can even detect circularly polarised light — something humans cannot normally see. See more such examples in the next section. By studying such natural systems, scientists hope to build new sensors and imaging technologies.
Mantis shrimp
Polarisation in Nature
04
Rainbows
When sunlight enters a raindrop, it bends, reflects inside, and comes out again. During this journey, the light becomes partially polarised, especially in certain directions. That means the light in a rainbow is not just colourful — it also has a hidden directional pattern. Scientists use polarising filters to study how rainbows form and how light behaves inside water droplets. So a rainbow is not just beautiful — it’s also a natural demonstration of polarised light.
Bees and their polarisation compass
Sunlight is originally unpolarised. But when it passes through the atmosphere it gets scattered, and light in different parts of the sky gets polarised in different directions. For example, the light is polarised differently when you look near the Sun compared to 90° away from it. The same pattern persists even when the Sun is hidden behind clouds.
Bees can detect this polarisation pattern of the sky, because they have special cells in their eyes which are sensitive to different polarisation directions. Bees use this information like a compass to navigate and find their way back to their hive. This allows them to travel long distances and still return home. Bees also translate this information into a "waggle dance" to communicate the direction and distance of food sources to other bees.
Ants do that too...
Some ants, especially desert ants, use the polarisation of the sky to navigate. When they leave their nest to search for food, they keep track of direction using this invisible pattern. In addition to the polarization compass, ants may also use the sun itself, step count (yes!), landmarks, and in some contexts, the geomagnetic field. It’s like having a built-in GPS using multiple signals. Studies have shown that this system can be modeled to create low-power, accurate navigation sensors for robots.
Cuttle fish
Their skin contains structures that reflect light in specific polarisation patterns. They use this ability for camouflage and communication, sending signals that other cuttlefish can detect but predators may not notice. This gives them a kind of “hidden channel” of communication.
Cuttlefish can both see and produce polarised light. They have the most acute polarization vision among animals. Their eyes are also sensitive to polarisation, helping them distinguish objects even in dim or muddy water.
Octopus
Octopuses can detect polarised light even though they do not see colour the way humans do. This helps them spot prey and objects that might otherwise blend into the background. Polarisation can reveal contrast and patterns that normal vision might miss. Combined with their ability to change colour and texture, this makes them highly effective hunters. They are using a completely different way of “seeing” the world.
Interesting Uses of Polarisation
05
Sunglasses
Polarised sunglasses are designed to reduce glare, especially from flat surfaces like water or roads. Reflected light from these surfaces is often horizontally polarised, which can be very bright and uncomfortable. The sunglasses contain a vertical polarising filter that blocks this direction, allowing only certain polarisations through. This improves contrast and visibility, helping you see more clearly. That’s why, if they wear sunglasses, fishermen can see into water and drivers can see the road better.
You can test this for yourself. Observe objects in your house kept on or near shiny surfaces like tiles, kitchen counter or wnidow panes. Note their reflection on these surfaces. Now look at the reflections through one of the polarising filters. Rotate the filter slowly. Do you see the reflections almost disappear when the filter is in a specific angle?
3D movies
In 3D movies, two slightly different images are projected onto the screen — one for each eye. These images are polarised differently (often using circular polarisation, which is explained in the video). The special glasses you wear have filters which ensure that each eye sees only its intended image. Your brain combines these two images to create a sense of depth and makes it appear 3D. Without polarisation, both eyes would see both images, and the 3D effect would disappear.
Stress Tests
Engineers use polarised light to study stress inside materials like plastic or glass. When these materials are under stress, they become birefringent, just like your tape. Between crossed polarisers, this reveals colourful patterns showing where the stress is strongest. This indicates where the material is weakest. These tests helps engineers design safer structures, from bridges to airplane parts.
LCD screens
LCD screens (like the screens in your phones and laptops) rely on polarisation to control each pixel.
- Light from a backlight first passes through a polariser.
- Then the polarised light goes through a layer of liquid crystals. These crystals change their orientation when electricity is applied. This changes how they rotate the polarisation of light. A group of such tiny crystals corresponds to each pixel on your screen.
- A second polariser either allows the light through or blocks it, creating bright or dark pixels on your screen. By controlling millions of these pixels, the screen forms images.
That’s why your screen looked dark when viewed through your polarising film at certain angles.Play video
Gemology
Gemologists use an instrument called polariscope. The polariscope comprises two filters placed in a "crossed" position. A gem is placed between them and rotated 360 degrees. By observing how the gemstone interacts with the polarised light, expert gemologists can tell which kind of stone it is and whether the gem is natural or synthetic. They can also identify specific minerals inside it and check if there are internal strain marks. This helps in deciding the value of the precious stones.
Gems like sapphire, tourmaline, or quartz go from light to dark four times (once every 90 degrees).
Gems like spinel, diamond, or glass remain dark throughout a 360 degree rotation.
Play video
Polarisation Microscopy
In a polarisation microscope, objects are viewed not only through lenses that magnify. They are at the same time placed between crossed polarising filters too. Birefringent parts in the material will exhibit beautiful colours that reveal information about the material’s internal structure, thickness, stress, etc. Geologists use this information to identify minerals and understand how rocks were formed. In biology, many structures inside living organisms are too transparent to see clearly under normal light. But polarised light reveals detailed information about such structures. For eg., collagen fibres. Chemists use polarised light to detect how molecules are shaped and arranged, especially when they are mirror images of each other and can't be easily distinguished otherwise.
Cholesterol crystals, photographed by the chemist Vance Williams
Did you notice the colourful images in all the title slides in this presentation? They were all taken with polarisation microscopes!
More Fun Stuff
06
Austine Wood Comarow's Kinetic Polages (Polarisation Collages)
Some inspiration for your next Light Canvas
Artist: Austine Wood Comarow She came up with the idea of Polage (Polarised Light Collage) in 1967 when her husband showed her that a crumpled piece of cellophane turns colourful when placed between polarising films. Check out her stunning portfolio on her website.
Micro photography
Peter Juzak's microphotography... See sulphur, vitamin C, urea, etc in a new light!
Artist or Scientist??
Carol Roullard's crystal landscapes... that is Vanilla btw :)
Sugar twists
Why sugar is called Dextrose!
Share your feedback for this activity
Why sugar is called Dextrose!
Exit
Lorem ipsum dolor
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua, sed do eiusmod.
a. Take 2-3 acetate sheets (of the same size as your drawing) b. Cover each of them with different number of layers of tape. c. Aligning them with your original drawing, trace different parts of your picture on these acetate sheets. These will form layers in your Polage. d. Now take a precision knife/craft knife (Ask a parent for help). Cut out some of the outlines in each of your acetate sheets.
Step 2
Choose / draw a picture on one of your remaining acetate sheets. It is useful to have wide outlines that are easy to cut out.
Step 1
Mount 1 or 2 of these acetate cutouts on your base. Place against a bright laptop screen. View through a slowly-rotating polarisation filter.. Isn't this magical!
Step 3
Lorem ipsum dolor
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua, sed do eiusmod.