Basic Star Trails Shot
Star trail shots make truly beautiful photos. They are really not that hard to capture - they just require a lot of time to get a good shot. Most star trail exposures will be several hours in length. When you make a mistake and need to restart the shot, you may have just wasted several hours of time.
In this shot aove the expsoure was about ~45 mins. Let's go over how I setup the shot.
With star trail photos a tripod is mandatory. The heavier and sturdier the tripod the better. However you can use your camera bag or other weights to weight down a standard tripod if you need to.
The second most crititcal aspect of setting up the shot is making sure that you are in an area that is protected from the wind. Since your exposure is so long you may find that a windy night will really mess up the focus on the shot.
Wehn you have your location and tripod setup it is now time to frame your shot. For this step you will want to change your aperture, shutter and falsh settings so that you can take some sample shots without having to wait for the long exposure. Take a few normal shots with the flash to make sur eyou like your composition and arrangement. make adjustments as needed until you find the composition you like. Try to have something in the foreground, a tree, rock, building, mountain, etc all make great foreground elements for star trail photography.
Once you have your shot composed the way you want it you can now setup your expsoure settings. For star trail photography you will be using the "BULB" setting within your camera. This allows you to hold the shutter open until you manually close it. For this step a shutter release cable is pretty mandatory so that you can lock the shutter open without having to hold your finger against your camera.
The last step in star trail photography is knowing just how long to keep the shutter open. There is a little bit of both an art and a science to this. The science is that you do not want to let to much light in which will cause your sky to go grey and get a littl ebit of washout. On the other hand, you might not have several hours to commit to the time star trail. In the exampel above I used an aperture of f8 and an ISO of 200. Looking back I should have used an ISO of 100 to reduce as much noise as possible. I also would have liked to have used a larger aperture but I had limited time to work that night. Generally I try to capture star trail shots over an hour in length, using a middle to large aperture and an ISO of 100.
Ben Hall lives in the San Francisco Bay Area working as a software engineer. Photography is a side passion that Ben can't seem to get enough of. His favorite subjects are Landscapes, Underwater and action shots.