Sky Saturation

While using the dome as a source of photons helps us to get the saturation limit of the camera, it does not help us judge how quickly the camera saturates if we are pointing the telescope at the sky. To see this, we need to take images at increasing exposure times of the sky in an area that is clear of bright stars to determine how long it takes for the sky background to saturate our image. You can see from Figure 1(b) that the sky saturates in between about 30 and 40 seconds. This is about twice the time that it took for our image to saturate with the dome image.

Figure 1: The figure on the left (a) is the saturation plot that we got taking dome images. The figure on the right (b) is the saturation plot of the night sky. Both are obtained from cropped parts of the entire image to disclude any hot or dead pixels in our images.