Naff Movie into 'DVD Spectra'

Step 8 Results and imaging

The spectra you can see with this view can be quite detailed. You can easily see the Fraunhofer lines in the Sun's spectrum, down to the level of resolving the Sodium D lines. That's pretty good for a DVD! Looking at domestic bulbs and comparing fluorescent tubes to incandescent bulbs makes it obvious why some people can say colours can look strange in fluorescent light.

Trying to make images of these spectra tends to show up limitations in your equipment. With CCD and CMOS sensor chips you will notice that they are poor at showing the strong yellows and cyans from the naked eye spectra, and don't really stretch far into the deep reds and ultraviolets. This is mainly due to the RGB filters they use within the sensors which only respond well to strong red, green and blue.

You will also notice that most point and shoot digital cameras find it impossible to make a accurate focus on the lines in the spectra. For good results you need a camera where you can set your own close macro focus. The results you see above are from a consumer webcam fixed to the front of the DVD Spectra. Its cheap enough to have a manual focus.