Astrophotography Made Easy: The Astrotrac
- By: Luis Argerich
Any photographer that tried to photograph the night sky knows that the big problem to make beautiful pictures of the stars is to avoid star-trails produced by the earth rotation during a long-exposure.
Without a tracking device you can afford exposure times from 2 to 20 seconds using a wide angle lens. That’s usually not enough to capture the nebulae, the Milky Way and other faint details from the night sky. To get more detail you need longer exposures and to get longer exposures you need a tracking mount. Astronomy mounts for telescopes are heavy and require a complex setup, the solution is the Astrotrac.
The Astrotrac is a very portable and efficient tracking mount that goes between your tripod and a tripod head. The setup is simple: tripod+head1+astrotrac+head2+camera.
One assembled you just need to align the unit pointing it to the North or South Celestial pole. The unit comes with a polar-scope that can be used to search for Polaris in the North Hemisphere making alignment a breeze. Even without a polar-scope you can just use a compass to point it north or south and dial-in your latitude as the declination in your tripod head and the alignment will be good enough. It only takes 1 or 2 minutes!
With the AstroTrac running you can take exposures of 1,2,3,5 and even 10 minutes without noticing star-trails. This is incredibly useful to capture wide views of the sky, nebulae, globular and open clusters, galaxies and most typical deep sky targets instead of using a telescope you use a lens.
The AstroTrac is powered by 12v, it can go to a car socket, a 12v gel battery or an AA battery-holder that you can order optionally. I use a 12v 7A gel battery and it lasts for many nights with a single charge, it’s compact and easy to carry too.
The AstroTrac is a very portable and useful device for photographers interested in the night sky, you just need to carry the unit, a battery and optionally a compass. You don’t have to be an astrophotographer it also helps a lot with nightscapes and it can even track for the moon.
More photos made with the AstroTrac at the Nighstcape Gallery of my website: www.luisargerich.com/nightscapes