Trying out Star Trails

This morning, as it was a clear night, I decided that I would try and see if I could take some star trails. I've never taken any before so I went out as a learning experience and to become more comfortable with being out on my own in the middle of no-where in the dark. I took the car to increae my illusion of safety and parked up on a small lane slightly to the north east or where I live. Although there was still quite a bit of ambient light around as it was a crecent moon there were still a lot of stars to be seen with the naked eye. Whether they would come out on the camera or not I was unsure of. I started off with some quick exposures, mainly because despite it being a back road and I thought, pretty deserted, one person drove past while I was taking pictures and one person rode past on a bike! My exposures in these two cases were not so much 'I'll expose it for x seconds', rather 'there's light coming, close the shutter'.

The first picture here is a 79 second exposure. There are very few stars coming out and they are quite faint (If you have a dark monitor I suspect that you may not be able to see them) Obviously I needed a longer exposure.

Stars 2

The second image is 348 seconds. In this one the stars are a bit brighter and you can also clearly see the motion of the earth. At this point I thought I might be getting somewhere.

Stars 1

After this and since it was getting cold and I was getting tired (not a good thing if you've got to drive home) I tried one longer exposure. This photo was a 1252 second exposure. You can clearly see the beginning of some cool star trails but it's overshadowed by the red cast that photo has taken on. The brightness level of the red is also not centrally placed which I find kind of odd. I wonder what has made it - whether it's too much ambient light or just something inherent with my camera and lens combination with such a long exposure.

Stars 3

I tried my best to clear up the red and turn it darker but at the moment I'm struggling to think of a way to get it out without losing all the lighter star detail. If you have an idea let me know.

Stars 3 Copy

So it seems that what I need to do is take several 'short' exposures at some time between 350 and 1300 seconds and then layer them one on top of the other to produce a composite with hopefully a decent star trail. Or maybe I just need to be somewhere darker? If it's not cloudy again tonight and I'm not too tired (I still woke up at 0830 this morning despite being awake a good portion of the night) I might try again. It's incredibly boring though being out on your own, even when you are listening to an audiobook on your mp3 player. A few minutes exposure seems to take hours.