You may also use your spectroscope to look at neon signs, sodium vapor lights, and mercury vapor lights. If your school has gas vapor lamps containing hydrogen, helium, neon, or argon, you may use your spectroscope to observe the emission line spectra of these gases. You may be able to use your spectroscope to observe the dark lines in the solar spectrum. The dark lines in the solar spectrum result from the absorption of some of the sun's visible light by the gases of the earth's atmosphere. This type of camera oprerates in the same way as an ordinary camera except that is has no film.
Light is gathered on screen of a CCD and transferred to a digital memory in the camera.
When the digital memory is downloaded into a computer, the image can be seen and printed. If you have access to one these cameras, you can see how images are collected by modern telescopes. If possible, enlarge an image from a digital camera on a computer screen. As the image enlarges, you will begin to see little squares called pixels. Pixels are the units of digital images and they are usually too small to be noticed, but the images of distant objects recorded by the Hubble Space Telescope often show the pixels.