Filter Systems

No scientific camera is complete without restricting the full sensitivity range of the sensor to a specific bandpass, such as the Johnson/Cousins UBVRcIc set. This lecture describes the various wide/medium/narrow bandpass filter systems commonly used, gives examples of how blue and red bandpasses give different views of the sky, and highlights possible problems with filters and their use. We conclude with some closeup details of various cameras and filters that are commonly available.