See this is the thing for some of us 5-6hrs sleep is like others 10hrs of sleep
4-5 hrs sleep is like a 6 hour snooze to others
I went to sleep at 1am got up at 5am to pack my kit up! All up 4 hrs and then back to the number crunching and designing.
The sky was really soupy last night which was a shame as my normal FWHM for Luminance is about 3, last night it was mid 5's its a stark contrast to see the difference in details from 3 to 5 almost like somebody put a opaque piece of perspex infront of the tube!