Whereas sound consists of wave motion of air or other objects, light is consists of wave motion of both electric and magnetic force fields together. Just like other wave forms, light waves have the characteristics of wavelength. The amplitude of a light wave corresponds to how bright the light is. This is similar to how loud a sound is. Photometry is the science of measuring light intensity.
Photographers use photometers to tell how bright the light is.
Wavelength of light Just as different wavelengths of sound are detected as different notes or pitches, different wavelengths of visible light are detected as different colors. White light and the spectrum of colors Normally, the light you see from a bright object, such as a light bulb, is considered white light. In reality, it consists of the colors that you see in a rainbow. This is called the visible spectrum. All of the wavelengths from very long to visible to very short make up the electromagnetic spectrum .