Robert J. Cumming, an astronomer in Sweden, and several colleagues at various astronomical research institutions in Europe, have submitted for publication a scholarly journal article arguing, in all seriousness, that every observatory should have a disco ball.
The authors note that pinhole cameras are frequently used in observatories. A disco ball, with its hundreds of mirrored surfaces, is basically a pinhole camera with hundreds of different apertures. They are cheap and readily available, thus avoiding serious expense in acquiring a specialized tool for observing bright objects, such as the sun. The article describes at length how the authors use a disco ball to observe a solar eclipse.