The spectroscope can be built using a recycled piece of DVD or a commercial transmission diffraction grating (the typical setup for a pocket spectroscope), replacing the eye with the camera (figure 3). There are two ways of obtaining spectral lines. The first and most simple one is placing a grating in front of the camera lens (with some adhesive tape), and then make a thin slit to put it in front of the light source, in order to create a thin line spectrum. In our case we used two razor blades close to each other. This setup usually requires a darkened room.