My first attempt at Star Trails the glow on the foreground is because the moon is behind us to our left so it lights up the mountains and lake. Took our lawn chairs and goose down lap blankets, hats, gloves
and warm jackets. We sat and watched the sun set behind the mountains. The thermos of coffee was certainly a hit. Temperature went from 62 degrees f to 36 degrees f in 3 hrs. But we were at 5000 ft elevation. Still experimenting with aperture and time settings but I am pleased with the first try. Fstop Aperture F4.5 Time 25 minutes. but it worked because the moon was so bright behind us. I would go at least an hour if there were no moon. If you shoot at F5.6 extend the times by at least a 1.5X more.