Select an astrophotography telescope based on the celestial objects you aim to photograph. This art form feels incredible as you capture an image of Jupiter or a galaxy many light-years away from your backyard. (You’ll be sharing photos with your friends, on your phone, in no time!)
Starry nightscapes make captivating images as the Milky Way stretches across the sky. However, choosing the right gear makes all the difference in celestial imaging. For example, taking photos of deep-sky objects involves long exposures to capture the object’s faint light. This guide aims to help you select an astrophotography telescope.
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Decide on Your Astrophotography Camera & Mount
To select an astrophotography telescope, decide if you’ll use a DSLR (or similar), smartphone, or dedicated cooled CCD camera. It makes a difference in the type of telescope you’ll use.
For the best images without elongated stars and streaks, your scope and camera must track the sky object to focus correctly. So that’s why the mount is just as important as the telescope for astrophotography. It compensates for Earth’s rotation to track the target throughout the exposure.
What Type of Astrophotography Interests You?
There are different types of astrophotography, so determining what celestial objects capture your imagination helps you decide how to select an astrophotography telescope.
Start your new hobby slowly. A modern DSLR camera with kit lenses and a tripod will take surprisingly decent pictures of the Moon or the Milky Way. But as you gain experience, you’ll want to take more detailed photos using a telescope.
A larger mirror diameter, lens, or aperture on your telescope means it gathers more light and has a higher resolution. In other words, larger telescopes can see more fine detail.
Longer focal lengths give you greater magnifications to take larger images. Galaxies and nebulae are faint objects, so you need a large-aperture telescope. But planets need a longer focal length to get views at higher magnification AND a large aperture to get high resolution.
Bird, Bug, and Wildlife Photography
Choose a telescope like the Celestron PowerSeeker 127EQ to view the moon at night and birds by day. This telescope is also a good selection for capturing night sky images.
Landscape (Wide-field) Astrophotography
Nightscapes are landscape astrophotography that uses a camera lens instead of a telescope. It allows you to feel your interest level in this hobby without a significant financial investment.
DSLR (digital single-lens reflex) cameras are great for
- Capturing nightscapes
- Wide-field objects
- Lunar imaging
- Deep-sky objects
You can change the ISO level (altering light sensitivity), have remote shutter capability (intervalometer), and manage your exposure times. DSLRs attach to your astrophotography telescope with a T-ring (fits a camera like a lens) and a nosepiece (fits into the telescope.)
Photos like the one above are composites of multiple 30-second exposures. They get manually stacked in Photoshop or a program like Deep Sky Stacker to reduce unwanted content or image noise and maintain pinpoint star shapes. Taking the exposures in astrophotography is only part of the process since you’ll also do post-editing for your desired final result.
Planetary or Moon Imaging
For the best planet or moon images, select an astrophotography telescope with a long focal length for high magnifications. That way, you’ll see details in Jupiter’s clouds or Saturn’s rings.
Large apertures give higher resolution at high magnification for planetary viewing. So the bigger your telescope, the better your chance of taking advantage of good seeing.
Smartphone Planetary Images
For astronomers just starting, planetary or moon photos turn out best with a refractor telescope. You can see our complete list of best telescopes for beginners, including the Celestron Inspire 100AZ. This telescope is excellent for viewing and taking pictures of planets and the moon. The Inspire has a lens cap you can convert into your smartphone holder, making it a good choice for basic astroimages.
The planets are very bright compared to deep-sky objects so you don’t need as long an exposure time to photograph them. It’s similar to daytime photography. So higher focal ratios of f/12 or f/20 are ideal for imaging solar system planets and the moon.
Camera Planetary Images
The highest-resolution planet images need a long focal length of about 3,000mm, but you can take lower-resolution photos starting with a 600mm focal length. More planet detail comes from more aperture and focal length combined with smaller pixels.
In planet or moon photography, you want a short exposure to record many frames per second. But the image must be bright enough for post-processing, which generally occurs with longer exposures. So, you’ll adjust your camera’s exposure and gain settings. If your telescope has planetary acquisition software, it can help with the adjustments.
Some features help you select an astrophotography telescope for planet or moon images. You’re looking for high-power views in a narrow field.
- Refractor optical design
- Tracking-capable Altazimuth or Equatorial mount
- 70mm Aperture and above for beginners
- Minimum 125mm Aperture for more serious astrophotographers
- 600mm focal length and above for beginners
- 1250mm – 3,000mm focal length for more serious astrophotographers
- f-ratios from f/11 to f/20.
Deep-sky Nebula and Clusters
Select an astrophotography telescope with an f-ratio of f/10 or f/15 for the best images of globular clusters and nebulae.
Nebulae are dust and gas clouds that vary in size and brightness, ideally meaning you’d have more than one telescope to view them. But, unfortunately, that becomes the “problem” with astrophotography. The more you get into the hobby, the more you want to capture various images.
Small scopes work well for large nebulae like the Orion Nebula. It’s very bright, so a shorter focal length gives you a wider field of view to see the entire object simultaneously. Of course, a larger scope reveals more closeup details because of their longer focal length, smaller field of view, and higher magnification.
|Sky Object||Aperture||Focal Length|
|Bright nebulae||5-8 inches||≤ 1,000mm|
|Faint nebulae||5-8 inches||≥ 1,000mm|
|Open clusters||≥ 5 inches||≥ 1,250mm|
|Globular clusters||≥ 11 inches||≥ 1,500mm|
Galaxies and Planetary Nebulae
Think big if you want to select an astrophotography telescope for galaxies and planetary nebulae. Large apertures and long focal lengths are necessary. These deep-sky objects are so faint, and far away that smaller telescopes only see them as smudges of light. A planetary nebula requires an 11-inch aperture for the best results.
- 8-11 inch (200 to 280mm) aperture
- 2000mm or greater focal length
How To Select an Astrophotography Telescope Wrap-up
There’s no one choice when selecting an astrophotography telescope. However, a 5 to 8-inch aperture with a minimum focal length of 1,000mm lets you image most sky objects. You’ll get the detail you want with an amateur-level telescope.