Frequently Asked Questions

  1. Where in the picture do I find the Sun / the Earth?
    Nowhere. The picture was taken from Earth, with the camera pointed towards the sky. Since all pictures were taken at night, the sun is obviously not in the picture, either. The situation is similar to photos taken at a party, where you (the photographer) never appear in your own shots, because you are behind the camera!
  2. I have seen other Milky Way panoramas. What makes your Milky Way Panorama 2.0 special?
    Several things:
    1. It covers the full 360°×180° sky.
    2. Its high resolution of 36 arcseconds/pixel. Since a full circle has 360×3600 = 1,296,000 arcseconds, this translates into a size of 36,000×18,000 pixels.
    3. Its photometric accuracy and faithful depiction of galactic dust and the halo of unresolved stars. The fields were photometrically calibrated using standard catalog stars and sky background data from the Pioneer 10 and 11 space probes. This way, the part of the night sky background resulting from artificial light pollution, air glow and zodiacal light could be eliminated while preserving large-scale star and dust clouds.
      For more details, see this paper, published in PASP 121, 1180-1187 (2009).
    4. Its high 18-bit dynamic range. Three different exposure times (240 s, 15 s and 0.5 s) were used. Five frames were taken for each exposure time and filter setting.
  3. There are so many multi-gigapixel panoramas on the web these days. At 648 Megapixels, your panorama looks kind of small in comparison. Can't you do a 70 Gigapixel panorama?
    The multi-gigapixel panoramas were all shot in broad daylight, with a typical exposure time of 1/100 s. For a night-sky panorama, a single field required an exposure time of about 90 minutes. Hence, you shoot far fewer fields in a given amount of time.
  4. When comparing your new and old panoramas, I find that the older one provides a better contrast. The new one looks a little hazy.
    This is due to the fact that the new panorama was processed to preserve the glow of the faint, unresolved background stars. Some people like the higher contrast of the old image, but the new panorama is a better depiction of reality.
  5. How can I get a poster / digital version / image license?
    See the Publications and "Getting the panorama…" links.