Orion Star Trails in the Moonlight

Orion ascends into the sky on a clear autumn night, with its stars drawing trails behind it as it rises.

Only on November nights is it possible to capture Orion rising in the evening sky. Here, I used the light of the waxing gibbous Moon to illuminate the landscape … and the sky, creating the deep blue tint.

The lead image above is an example of a star trail, a long exposure that uses Earth’s rotation to turn the stars into streaks across the sky. In the old days of film you would create such an exposure by opening the shutter for an hour or more and hoping for the best.

Today, with digital cameras, the usual method is to shoot lots of short exposures, perhaps no more than 20 to 40 seconds each in rapid succession. You then stack them later in Photoshop or other specialized software to create the digital equivalent of a single long exposure.

The image above is a stack of 350 images taken over 2.5 hours.

With a folder of such images, you can either stack them to create a single image, such as above, or string them together in time to create a time-lapse of the stars moving across the sky. The short video below shows the result. Enlarge the screen and click HD for the best quality.

For the still image and time-lapse, I used the Advanced Stacker Plus actions from StarCircleAcademy to do the stacking in Photoshop and create the tapering star trail effect. A separate exposure after the main trail set added the point-like stars at the end of the trails.

My tutorial on Vimeo provides all the details on how to shoot, then stack, such a star trail image…

… While this video illustrates how to capture and process nightscapes shot under the light of the Moon.

Enjoy the videos! And happy trails!

— Alan, November 24, 2015 / © 2015 Alan Dyer / www.amazingsky.com