Feb 23, 2012, 17:50
I came across this breathtaking Astronomy Picture of the Day and it captured my attention not only because it's from the state of Victoria, Australia, but also because of the interesting technique used.
Credit & Copyright: Alex Cherney
Apparently when taking long exposures of the night sky, the earth's rotation causes the stars to shift which will leave light trails in your photos. To get the effect above where the stars appear fixed and yet have a rich sky, most astrophotographers use a motorised equatorial mount, which basically is a tripod which rotates automatically to compensate for the earth's rotation. They're not cheap.
In the photo above though, Alex gets by with just a normal tripod but with 7 x 15 second shots. He then processed the sky and ground separately - software was used to de-rotate the sky, and then stitched together with the ground in photoshop.
http://apod.nasa.gov/apod/ap100823.html
Inspirational!
Credit & Copyright: Alex Cherney
Apparently when taking long exposures of the night sky, the earth's rotation causes the stars to shift which will leave light trails in your photos. To get the effect above where the stars appear fixed and yet have a rich sky, most astrophotographers use a motorised equatorial mount, which basically is a tripod which rotates automatically to compensate for the earth's rotation. They're not cheap.
In the photo above though, Alex gets by with just a normal tripod but with 7 x 15 second shots. He then processed the sky and ground separately - software was used to de-rotate the sky, and then stitched together with the ground in photoshop.
Quote:For this photo I took 7 images and then processed them separately for the sky and ground. The ground images were simply averaged in Registax and sky photos were aligned and de-rotated in DeepSkyStacker. The two halves were then blended back together in Photoshop.
http://apod.nasa.gov/apod/ap100823.html
Inspirational!
