Online Photography School
How To Photograph Star Trails
Photographing Star Trails is a unique way to capture the night sky in a photograph. A star trail occurs when you photograph the stars over a long period of time, from minutes to hours.
Many photographers who photograph star trails use a technique of shooting multiple shorter length time exposures and stack them during post-production using Adobe Photoshop or another program that will allow you to stack multiple files into one photograph. This allows them to produce a more dramatic effect in the final image. Another reason to use shorter exposures is to reduce the occurrence of noise that can show up in an image captured during long exposure shooting. In addition to shooting multiple images and stacking them, using as low an ISO as possible will also limit noise in the final image.
To capture the maximum amount of light put out by a faint light source such as stars, you’re going to need to use a fast aperture.
You probably think that the photo is completely manipulated and is impossible to photograph this phenomenon.
Today I’m going to show you that is real and anyone can capture the movement of the stars (or the earth), although in some cases you do require the intervention of a software like Photoshop, its only function is to fuse the different images to complete the effect.
The trick is to find the North Star, as the earth revolves around the sun on an imaginary axis, which points north. Therefore if we point our camera at the North Star, we get a visual of the stars rotating around the earth, but really it is the earth that is spinning.
# 1: Gear
First, you will need the following
– Camera with “BULB” mode.
– Remote or cable release.
– Optional: iOS or Android Application that allows finding the location of the pole star.
– A lot of Patience.
Understanding how star trails are formed is crucial to nailing the composition. This is also important to consider when selecting a location. Star trails are essentially formed by the (apparent) motion of the stars in the sky due to the rotation of the earth. Every 4 minutes, the earth rotates exactly 1° (360° in 24 hours). Thus, for a viewer on earth, it would seem as though the stars track 1° of their complete arc through the sky every 4 minutes. This may not seem like much, but over the long exposures needed for star trails, those minutes and degrees add up. [Read More]
# 2: Find the right place
In order for your photograph to be successful, you have to plan it in advance. During the day, look for a place that is preferably away from the city, since we don’t want any light pollution that can compromise our photo.
# 3: Prepare your equipment properly
I recommend to do this under the moonlight as this can help illuminate your subject or landscape without over exposing the stars (depending where you point your camera). Arrange your camera on your tripod and make some test shots. Normally you wont see anything using the “view finder” so you’ll have to do your test shots with high ISO and the maximum aperture of your lens. When you have the desired composition, adjust your ISO and aperture to achieve the desired sharpness. In these low-light, auto focus is practically impossible, so you will have to focus in manual mode, or by lighting up your target with a flashlight to focus.
Mixing variables ISO, aperture and shutter speed, change your exposure to achieve the desired effect, remember that what we are looking for is to trace the trail of the stars to earth movement. For example, when we take a photograph in the city during the night and leave our aperture open for a few seconds, we can see how cars trace a line of very interesting colors, we apply this same concept here, but with much longer exposure.