Normally we do not open the shutters during the day. As any kid who has used a magnifying glass in the sun knows, direct sunlight and optics are a powerful combination. The amount of sunlight a 10 meter mirror could gather would result in something a bit more powerful than a child’s toy.
Occasionally it is necessary to do maintenance on the shutters, in the process opening the shutters during the day. It is a careful operation, turning the dome away from the Sun and positioning the telescope away from the opening. Still, it is an odd situation, daylight streaming into the dome, a place normally only lit by starlight or the dome florescents. Then there is the view…
