Once the image is focused and magnified by the telescope, the image can be viewed several ways. Visually the image can be viewed by the eye. The image can be captured by a film camera (mostly historical), digital camera or video, or Charge-Couple Device (CCD); the telescope becomes the camera lens; Digital or Photographic astrophotography .
A spectroscope breaks the light of the incoming image into its component wavelengths for study, called spectroscopy . And a photometer measures the amount of incoming light.