Getting Started with Equatorial Mounts: EQ vs Alt-Az for Astrophotography
The mount is the most important piece of equipment in your astrophotography setup. A great camera on a poor mount will produce blurry images, while a modest camera on a solid mount can deliver stunning results. Here’s how to choose.
Why equatorial?
Earth rotates, and so does the night sky. An equatorial mount has one axis aligned with Earth’s rotational axis, allowing it to track celestial objects with a single motor. This is essential for long-exposure deep-sky imaging where even a few seconds of drift creates star trails.
Alt-azimuth mounts (like Dobsonians or simple camera tripods) move in up-down and left-right axes. While some computerized alt-az mounts can track objects, they introduce field rotation during long exposures — the stars stay sharp but the image slowly spins around the center.
German equatorial vs star trackers
For camera lenses and small refractors, a portable star tracker like the iOptron SkyGuider Pro is an excellent choice. It’s lightweight, battery-powered, and tracks accurately enough for 1-2 minute exposures with wide-field lenses.
For telescopes, you need a German equatorial mount (GEM). The iOptron CEM series and GEM series offer excellent payload capacity, precise GoTo pointing, and the stability needed for long imaging sessions with autoguiding.
The golden rule
Never load a mount beyond 60% of its rated payload capacity for imaging. A mount rated at 20kg should carry no more than 12kg of telescope, camera, and accessories. This ensures smooth tracking and reduces the load on the autoguider.
Check out our mount selection from iOptron for options ranging from portable star trackers to heavy-duty observatory mounts.