After my crazy first attempt at star trails photography, which by the way was not hugely successfull, I gave it a sincere shot two weeks ago. Considering all the lessons learnt from my first try, I decided to try out a place that's not awfully light polluted like Valley Forge National park. After some googling, I found out about Cherry Springs state park, which claimed to be 'gold rated' for dark skies in the east coast of US. Wonderful! In a split second (and out of sheer enthusiasm), I decided to do the 200 mile drive all by myself to photograph a few stars.
I checked the weather - everything looked alright. On my way, I casually looked up at the sky and I saw the moon staring at my face. Before I could appreciate the beauty of it, I realized that such a bright moon would completely screw up the visibility in the sky! Oops! I should have checked the moon calendar. Since I had driven about 150 miles at that point, I decided to continue with the trip. I reached the park around 8pm, only to see a vacant astronomy field and not a soul around. I walked around the park (with the moon light shining, I did not even need a flashlight) to understand my coordinates. When I thought I had the whole field to myself, I see another car pull over. I was more surprised to see an Indian couple from New Jersey. After a few minutes of conversations, I understood they love nature and wanted to check this park out. And they did not even have a camera or a telescope. Whoa! after all, I was not as bad, there are people with dangerous levels of enthusiasm!
I then decided on a spot and setup my tripod. Any exposure more than 30 seconds made it look like a daylight photograph, thanks to the Moon who seemed like he was continously mocking at me! Few random conversations and some unsatisfying pictures of the moon later, I decided to sleep in my car hoping I might be able to get some sunrise shots. The morning was totally cloudy which made me return back home completely unsatisfied.
As I was narrating this story to one of my colleagues Eric last week, he showed interest in going there again. My enthusiasm rose again. I checked the weather, moon calendar, etc., and decided to make it there this past weekend. And this time, Eric drove. When we reached the park saturday evening around 7pm, I just could not believe my eyes. There were 100s of people, most of them setting up humungous telescopes! In a short while, the sky started becoming darker and at about 8.30pm, the sky was like one huge planetarium screen. It was one amazing sight and I will not forget the view for a while now!
I then setup my tripod and started taking pictures, each of my shots needing exposures of about 20 minutes or so. We spent the new few hours taking multiple photographs and amazing ourself at the sight! Thanks to Eric, he brought a couple of chairs where we sat and discussed everything under the sky (literally!) while we were waiting for the camera to take the pictures. We left the place around 11pm. We would have spent a few more hours only if the weather was not getting unbearable cold. Here are some pictures!
For any photographer looking for tips on star trail photography, here is some technical info from my experience:
I first checked the ambient lighting by shooting a 30 second exposure at f/4 and ISO 1600. Once I knew how my camera sees the light, I reduced the ISO to about 200 and increased the exposure to 20 minutes. I had my camera set on a tripod and used a remote control to fire the shot. Since I also had the high exposure noise reduction setting ON in my camera, I had to wait for an additional 20 minutes for the camera to cancel out any noise. After 40 minutes, I got this photograph where I could see the trails rotating around Polaris. After two trips to the place and numerous attempts at star trails, I finally got a photograph that I was satisfied with! I was one happy camper for those few seconds! Regarding the composition, I used a 10-20mm wide angle lens and included a little bit of tree line in the horizon so that it adds perspective to the photograph.