Testing ISO Settings for the Night Sky
After chasing the Lyrids, I decided to create some test shots at different ISOs for my area. I shot my Lyrid footage at ISO 3200 and it was too high. Last night was clear, so I went out about an hour after sunset and took this series of 30 second time exposures starting at ISO 1600 and ending at 100. These were taken with my trusty Nikon D5300, Rokinon 16mm lens at f2 and Hoya Red Intensifier filter.
ISO Test
From Top to Bottom:
ISO 1600
ISO 800
ISO 400
ISO 200
ISO 100
Light pollution isn't the only thing I have to deal with. You'll notice that I also have a lot of trees.
Although the Rule of 500 gives me a time exposure value slightly over 30 seconds, I can see elongated stars in those images. I backed the time down to 25 seconds and settled at ISO 200 (as I look at that now, I would probably step up to either ISO 250 or 320 at 25 seconds with this setup). My raw test shot at ISO 200 had to be lightened in Photoshop and surprise! A couple of meteor trails showed up in the image.