Audiovisual Materials
The Audiovisual Materials sub-series includes photographs, lantern slides, photo negatives, etchings, and microfilm. These materials document various astronomical subject matter, people, the Detroit Observatory, astronomical observations (including solar flares, planets, stars, and Halley's Comet) other observatories around the world, and scientific instruments.
Additionally, moving image and audio recordings contain historic footage of various observations as well as Observatory construction and restoration projects.