# How To Draw A Spectrum

## Video: How To Draw A Spectrum

The spectrum, as is known, arises from the decomposition of light by a prism or a diffraction grating. He is so beautiful that he wants to be photographed or painted. It is quite possible to do this at home.

## Instructions

### Step 1

Take a sheet of plywood, plastic, or other easy-to-handle, opaque material. Its dimensions should be approximately 300 by 300 millimeters, the thickness is not critical. Cut a straight slit in its middle about 100 mm long and about 4 millimeters wide.

### Step 2

Place the sheet vertically. Make a stand for it so that you don't need to hold it in your hands, because you will have to hold two more objects in them.

### Step 3

Darken the room at least partially.

### Step 4

Turn on a continuous spectrum point light source. This can be, for example, a pocket torch based on an incandescent light bulb. Place it about 500 millimeters from the gap.

### Step 5

On the opposite side of the slot, place a sheet of plain paper at a 90-degree angle. Secure it.

### Step 6

Take a regular CD (a dark one like RW will not work). Place it between the slit and the sheet of paper so that the spectrum is projected onto it.

### Step 7

While holding the flashlight and disc, ask your assistant to take a photo of the resulting rainbow.

### Step 8

Then ask a helper to pick up colored pencils or a felt-tip pen. Hold the flashlight and dial so that the spectrum does not shift. Note that it is noticeably more sensitive to disc shift than flashlight shift. Have an assistant trace the spectrum with pencils or felt-tip pens that match the projected colors.

### Step 9

Remove the resulting sheet, then turn off the flashlight and disassemble the installation. Turn on the lights in the room. Compare the resulting photograph and drawing with each other.

### Step 10

Find the answer to the question why colors in any spectrum are always in the same order in a physics textbook. If you wish, find in it, or on the Internet, a color-to-wavelength table. Mark the drawing and photograph as appropriate.

### Step 11

Note that the wavelength of the shortest wavelength visible radiation is about half that of the longest wavelength. This interval is called an octave. From this point of view, the possibilities of human hearing are somewhat richer, since the ear distinguishes several octaves. However, in terms of the width of the range, expressed in absolute terms, vision certainly benefits.