There are two basic types of calibration frames you probably want to take; darks and flats.


Dark frames are exposures with the CCD
- Dome Flat screens are mounted in the dome.
- Lights are on the telescope. First turn on power strip, then push button to turn on lights. Lights can be dimmed. The lights are much brighter in R and I (and, obviously, CBB) than in B and V, so either set the light brighter for B and V, or take longer flats for these two filters.

- RF tube needs to be covered from inside to take darks with lights on.
- Allow ~15 for the camera to cool completely before beginning to take calibration frames.

m51-2
The above image shows M51 without calibration frames. Hot pixels, dust motes, vignetting, and other noise are very apparent.