I finally managed to get my camera and tripod set up last night for another try at the ‘time lapse star trail’ experiment. Lots of photographers have done it in the past, so it’s not ground-breaking, but I just wanted to do it myself. So, this first picture is my very first success at this, and it looks ‘kinda ok’, but it wasn’t what I was after. I set up the camera on my heavy tripod (heavy for stability), facing west, and set the camera for ‘bulb’ operation. Bulb means the shutter opens with the first click and stays open until you click again. I did a 10-minute exposure and got the results you see. This is NOT what I wanted or expected, but I figured out what was going on. I had the camera set for ISO 800, which meant it was behaving just as if it had FAST film in it, which you use for low-light conditions. So, there was enough moonlight spilling onto the trees to ‘paint’ them with light over the 10 minutes, giving the illusion of a daytime shot. Hmmm, time to re-group.
I changed the ISO setting to 100, faced the camera to the north (just for variety), and did another 10-minute shot. As it happened, right as I was ready to go, I saw an aircraft approaching, about to enter the shot, so I went ahead and opened the shutter just to see the effect on the picture. So, you’ll see a long continuous streak going from lower left to upper right – that’s the airplane. Just as an experiment, I added some light onto these trees just to highlight them – I used our big yellow flashlight for this, just kinda waved it around for a minute or so during the open shutter time. That’s why the trees don’t appear totally in silhouette.
These photos yield ‘star trails’, which are curved lines indicative of the rotation of the earth and giving apparent movement to the stars. If you’ll look *very* closely at this second photo, near top right, you’ll see a star with no trail. That is the North Star, and it always appears that way in this type of photo since it is located right above the axis of rotation of the earth, thus, no trail. At this point, you’ve either learned something, or you’re bored to death. Let me know 🙂
Now I’ve got to get out there with my telescope and see if I can re-learn how to use it – it’s been kinda gathering dust. My son Bret wants me to bring it with me to Canada in a couple of weeks, so it might be best if I appear to know what I’m doing. I have a camera adapter somewhere which is supposed to allow ‘astrophotography’ – if I find it, we’ll see how that goes.
So, a ‘techno-geek’ post, but maybe you didn’t mind too much.