Wilhelm Oswald Lohse (1845-1915) constructed a camera with which he took several hundred images, an
example is the Orion nebula on the left. The entire Potsdam plate collection contains more than
10 000 plates from the period of 1879-1970. The plates contain valuable astronomical
information easily to be retrieved. The Potsdam wide-field plate collection reflects also the
history and development of the Potsdam Observatory.
The archived astronomical wide-field photographic observations are now a part of the
existing virtual observatories world-wide. Their importance comes from the possibility
to monitor astronomical objects with long-term coverage. The capabilities of today's
scanners for quick plate digitization and the on-line access to the plate information
have increased the chances of scientific use of the archived observations. Information
about the wide-field photographic archives and their contents can be found in the
Wide-Field Plate Database (WFPDB), installed in Strasbourg and mirrored in Potsdam.
The development center is located in Sofia (http://www.skyarchive.org/).
Many other observatories possessing large archives such as Asiago,
the Royal Observatory of Belgium, Rozhen Observatory, the Institute
of Astronomy in Cambridge, David Dunlap Observatory, Bamberg, the
Royal Observatory of Edinburgh, Harvard College Observatory, Maria
Mitchell Observatory, Sonneberg Observatory, Midi-Pyrenees Observatory,
Valencia Observatory, the Main Astronomical Observatory Kiev, etc.
have started scanning projects on their archive plates.