Spectroscope Workshop

A spectroscope is a device that is used to analyse light by separating its parts into a spectrum.

On November 18th, 2015 I hosted an in-class workshop where I taught our class to build and use spectroscopes out of cereal boxes.

The spectroscopes we built used a CD to defract the light once the device is aimed at a light source.

How to Build Your Own Spectroscope:

Materials required:

– 1 cereal box
– 1 CD
– 2 Index Cards (Can be replaced with 2 razor blades)
– 60 degree angle (printable angles can be found online)
– black tape
– scissors
– ruler

Your spectroscope will look something like this:



– fold cereal box shut and tape the bottom edges so no light seeps in
– on the top left of the box measure roughly one-two inches and mark a line across the width of your box
– cut along the line and unfold the flaps that were created and cut the flaps off


– use your 60 degree angle and line it up to the top corner of the box so the hypotenuse of the triangle angles toward the center of the box. Measure and draw a line 3 inches from the top corner of the box. You will have a 3 inch line starting at the top corner of your box, and the line will lead ROUGHLY toward the center of your cereal box.

-cut those lines

-flip the box over and do the same thing on the other side



– cut a 1 inch high rectangle out on the opposite side of the slits. The rectangle should be the width of the box.

-Use your index cards or razor blades (sharp edges facing inward toward each other) to block out most of the rectangle you just cut out. Place them horizontally, closely together, leaving a 1mm gap between the cards. Tape the cards securely to the box.



-Tape the box closed

-Slide the CD into the slot


-Point the index card slit at a light and look into the square hole into the box at the bottom of the CD. You will see your bright white light bulb break up into its composing colours!


Here are some more photos from the spectroscope workshop:

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HereĀ are the final products: