Askar N210 210mm f/3.4 Newtonian Astrograph with Coma Corrector

Big-aperture, fast deep-sky imaging in a carbon fiber tube

The Askar N210 Newtonian Astrograph is a 210mm (8.3") f/3.4 reflector built for deep-sky astrophotography. It pairs a parabolic primary mirror with Askar's 0.95× triplet coma corrector for a 714mm focal length, and the corrector's M48 thread and standard 55mm back focus make connecting a dedicated astronomy camera simple. It's the larger sibling of the Askar N160, for imagers ready to step up from a small refractor to real aperture without paying large-refractor prices.

Key specs: 210mm aperture · 714mm focal length, f/3.4 with the included corrector (756mm, f/3.6 without) · parabolic primary · 0.95× triplet coma corrector · APS-C (28mm) image circle · 55mm back focus from M48 · carbon fiber tube · 9.8kg (21.6lb) with rings, handle, dovetail and corrector

What you can image

• Galaxies: with an APS-C camera the N210 frames about 1.9° × 1.3°, a good fit for the Whirlpool Galaxy, the Pinwheel Galaxy, Bode's Galaxy with the Cigar Galaxy, the Triangulum Galaxy and the Leo Triplet.
• Nebula detail: the Crescent Nebula, the Eastern Veil, the Cocoon Nebula and the Dumbbell Nebula, all targets Askar shows in its own N210 sample images.
• Smaller nebulae and clusters: the Eagle and Omega Nebulae, the Ring Nebula and globular clusters such as M13, where the fast mirror pulls in the faint outer stars.
• Narrowband from the city: f/3.4 makes narrowband imaging with a mono camera and filters much quicker than with a slow refractor.

With a 26MP APS-C camera such as the ZWO ASI2600MC Pro, the N210 works at about 1.09 arcseconds per pixel, a detailed scale that rewards a well-guided mount and steady skies.

How it works

Optics: a parabolic primary mirror forms the image, and the included 2" triplet coma corrector removes the comet-shaped stars a fast Newtonian otherwise shows at the edge of the field. The corrector also shortens the focal length slightly, from 756mm to 714mm, and brings the system from f/3.6 to f/3.4.

Connecting a camera: the corrector ends in an M48 × 0.75 thread, and the camera sensor goes 55mm behind it, the standard spacing most astronomy cameras reach with their included spacers. Askar includes 0.1mm, 0.2mm and 0.3mm shims (two of each) to fine-tune that spacing.

Mounting: the N210 comes with a pair of tube rings, a 400mm dovetail plate and a multifunctional handle across the top of the rings.

Collimation: every Newtonian needs its mirrors aligned now and then, and at f/3.4 the tolerance is tight. It takes a few minutes once you've learned it, and we're happy to show you how.

What to add for the best results

• A mount (required): plan on about 11kg (25lb) with a camera, focuser and guide scope. The ZWO AM5N carries 15kg (33lb) without a counterweight, and the Sky-Watcher EQ6-R Pro is a classic counterweighted choice.
• A camera (required): an APS-C cooled camera such as the ZWO ASI2600MC Pro (1.9° × 1.3°), or the ASI533MC Pro for a square 0.9° × 0.9° field on smaller galaxies. The ASI2600MC Air adds a built-in guide sensor and ASIAIR control.
• Guiding: at 714mm, guiding keeps stars round. The Askar 52mm Super ED guide scope (249.6mm) with a ZWO ASI120MM Mini or ASI220MM Mini guide camera works well.
• Control: the ZWO ASIAIR Plus runs the camera, mount, guiding and focuser from your phone or tablet.
• Autofocus: a ZWO EAFN keeps the fast mirror in focus as the temperature changes. Askar publishes an electronic focuser assembly diagram for the N210, and we can help you fit it.
• Filters: a 2" ZWO Duo-Band or Optolong L-eXtreme filter for nebulae from light-polluted skies with a color camera.
• Field power: a Celestron PowerTank Lithium Pro for nights away from an outlet.

Askar N210 vs. N160

See all Askar telescopes.

What's in the box

• Askar N210 optical tube
• Pair of tube rings
• 400mm dovetail plate
• Multifunctional handle
• 0.95× coma corrector (2")
• M58 to M48 adapter
• Spacing shims: 0.1mm, 0.2mm and 0.3mm, two of each
• Manual

The mount, camera, guide scope, focuser motor and filters are sold separately.

Askar N210 FAQ

Is the N210 a good first astrophotography telescope?

Usually not. A fast 210mm Newtonian is heavy, needs collimation and a strong mount, and at 714mm it shows every guiding error. Most people do better starting with a small refractor such as the Askar 60F and moving up to the N210 once they're comfortable with guiding and processing.

What mount do I need?

With a camera, guide scope and focuser the N210 comes to about 11kg (25lb). A mount rated for at least 15kg (33lb) for imaging is a good rule, such as the ZWO AM5N or the Sky-Watcher EQ6-R Pro. Smaller mounts and star trackers can't carry it.

N210 or N160?

The N210 collects about 70% more light and has a longer 714mm focal length for galaxies and nebula detail. The N160 weighs just over half as much, frames a wider 2.5° × 1.6° field, and works on a mid-size mount.

Which camera works best?

An APS-C or smaller cooled camera with 55mm of back focus, such as the ASI2600MC Pro or ASI533MC Pro. The corrector's image circle is 28mm, so full-frame sensors will show dark, distorted corners.

Can I use it for visual observing?

Askar designed the N210 as an astrograph and lists only camera adapters for it. If you want one telescope for both viewing and imaging, a refractor such as the Askar 91F is a better fit.

Does it need collimation?

Yes, like every Newtonian. Check it before each session, especially after driving to a dark site. We can show you how in our store.

Specifications