Orion 8 F/8 Ritchey-Chretien Astrograph Telescope Review


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This is the type of telescope buy that an experienced user looks for to take their imaging skills far beyond the mediocre pictures that come from smaller apertures and inferior optics.

To truly get some stunning snap shots of what exists beyond the clouds and our sun will require a generous budget, a highly-accurate and smooth mount, and the Orion 8” f/8 Ritchey-Chretien Astrograph telescope.

While 8” is far from being the largest scope on the block, it allows for some portability and compact benefits as the 10” model literally doubles in weight.

But, there’s still plenty to see and capture on camera.

If you want more quality out of your snap shots, the Astrograph is worthy of serious consideration.

Zooming in…

✔️ Best Feature: For astrophotography

Worst Feature: Price

👌 Ideal For: Celestial Observation, Stargazing, Lunar & Planetary Observation, DSO Viewing, Astrophotography, Experts

  • Optical Design: Ritchey-Chretien
  • Aperture: 200 mm
  • Focal Length: 1600
  • Focal Ratio: f/8
  • Eyepieces Included: None

Our Verdict: The Orion 8 F/8 Ritchey-Chretien Astrograph telescope is the epitome of high-quality in a telescope where you need it – everywhere. From the optics to the mounting bases, the Astrograph is fully-prepped and ready to be combined with quality imaging equipment and a heavy-duty computerized mount. Once you see what you can do with it, you’ll wish you bought it long ago.

Who is the Orion 8 f/8 Astrograph Best Suited to?

The Orion 8” F/8 Astrograph is a telescope for advanced and expert users. The scope is a standalone buy, so it’s assumed you already have a collection of accessories and gear or are willing to purchase everything needed to put the Astrograph to use.

Beginners and even intermediate users will struggle to justify buying this telescope as the tube may prove to be the cheaper purchase while the accessories and mount will come to a much higher price combined.

With all the imaging that will be done, a beginner should start with the basics. The Astrograph can provide stunning images that will require experience, equipment, and perhaps a lot of patience.

How Does the Orion 8 f/8 Astrograph Perform?

The Orion F/8 Astrograph is a fast Cassegrain telescope with a final f/8 focal ratio. To provide that extra speed, central obstruction is slightly higher than other alternatives. Still, due to the specialized RC optical design, you have the added benefits of a flat-field and chromatic aberration-free views that will bring your imaging to the next level.

Paying a hefty price for an 8” tube seems like a lot of money, and it is especially when it lacks essential equipment to get observing with out of the box. But, RC telescopes aren’t cheap, and they cost a heck of a lot more due to the hyperbolic mirrors that provide excellent imaging results – this is no beginner refractor, in fact it is featured on our best telescopes page for a reason. You’re also landing some custom touches from Orion that allows for mounting additional accessories – more on this below.

Simply put, the Astrograph performs. If you have the luxury of a large budget to acquire other essentials or already have some quality stuff, it’s so worth it.

Features & Benefits

Astrophotography

Just knowing the Astrograph is a Ritchey-Chretien telescope should say enough about its astrophotography potential. No coma, no color fringing – just raw impeccability for lunar, planetary, and long exposure photography. The telescope is extremely versatile as you can use additional accessories for various types of imaging. Focal reducers, focuser extension tubes, CCD cameras, DSLR cameras, computer control, guide scopes, and more.

Obviously, the tube is made for imaging, but you should be aware that it doesn’t come with any other necessary gear to get started. You will have to purchase the appropriate mount, eyepieces, and astro-imaging equipment separately.

Ritchey-Chretien Optics

The f/8 Astrograph is a Ritchey-Chretien telescope which is a variant of a Cassegrain. Unlike other Cassegrains that incorporate both mirrors and lenses, the RC uses hyperbolic mirrors and no lenses within the optical system. Like a Cassegrain, you can build an extremely compact tube while retaining a long focal length. But, this model has what I would call a fast focal ratio compared to its alternatives that usually have an f/10-f/15 speed.

The hyperbolic mirrors are the winning feature of an RC. They significantly reduce off-axis coma and chromatic aberration to provide sharp, high-contrast, color-true, and flat field viewing. Due to their quality and optical benefits, many professional astronomers opt for an RC telescope. Even the Hubble Space Telescope is an RC.

However, for as impressive as this telescope is for imaging, you may feel that an 8” Newtonian would provide a slightly better view for visual use, and you could be right. The Astrograph has a 47% secondary obstruction by diameter which essentially decreases the amount of available light transmission to the primary mirror because of the large size of the secondary mirror. An RC may have a slightly higher obstruction than other optical designs due to its faster focal ratio and short and compact tube design. However, some of the best astrophotography and Cassegrain telescopes hover around 40% obstruction, so it’s still within reasonable limits.

DSO & Planetary Observation

The Astrograph is made for imaging, but it doesn’t mean it can’t be used for visual when you’re not in the mood to get the camera gear setup. You will need a diagonal to make it easier for viewing. The field of view with AFOV 50-degree eyepieces are as expected for an 8” medium-speed telescope which isn’t very spectacular, but what you can see will be.

An 8” telescope allows you to see a whole lot more of everything, although not without its limitations. You will see with much clearer detail if you were using something smaller previously, and the ability to see a tad more under light-polluted skies will be extremely helpful. But, best use will be under dark skies.

You’ll see planets including Neptune and Pluto as star-like points. Excellent features within Jupiter’s cloud belts are visible, dark surfaces and ice caps on Mars, and ring division, moons, and cloud belts on Saturn. What exists beyond our own solar system will astound you. Several hundred of star clusters, nebulae, and galaxies can be explored.

Mounting Capabilities

Conveniently, the OTA comes with two dovetails for mounting a finder scope. You can choose which side of the focuser you’d prefer to mount the finder, or you can double up and use a red dot and an achromatic finder or a mini guide scope and reflex sight. The option is yours.

There is also a custom-designed, Vixen-style dovetail bar for piggybacking a DSLR or mounting a guide scope. They feature multiple through-holes for mounting scope or tube rings according to the space you need for your setup.

The 8” Astrograph has a Losmandy-style dovetail bar for mounting to a compatible EQ saddle plate to attach the tube to a mount. The Losmandy is wider than the Vixen and the dovetail bar runs the length of the tube, so you’ll have the benefit of balancing perfection along the Dec. axis. You may still need to use counterweight to help with balancing for heavy DSLR loads.

Limitations

Price

RC telescopes are very expensive. The hyperbolic mirrors require more precision and are difficult to make. It doesn’t help that this is a standalone buy, so you must have a collection of high-quality accessories ready to be used or you’ll have to be prepared to be spend considerably more to get observing and imaging. High-quality accessories are highly recommended to take full advantage of the Astrograph RC’s performance benefits.

Popular Questions

What Accessories are Included with the Orion 8” Astrograph?

While the Astrograph may be lacking standard accessories usually seen with cheaper telescopes, it does come with some very fine accessory features. You have two dovetail finder shoes, a Vixen-style dovetail for piggybacking imaging equipment or a second telescope, and a Losmandy dovetail bar for mounting to an EQ mount.

A 2” linear-bearing Crayford focuser is included and allows for handling heavy payloads without drawtube flexure. It can be rotated independently of the tube, has 10:1 precision for fine focus, and it also features tension adjustment and a drawtube locking knob.

Two 1” extension tubes and one 2” extension tubes are also included. You must purchase eyepieces, and a mount/tripod separately.

How Heavy is the F/8 Astrograph Ritchey-Chretien Telescope?

The Orion RC 8” f/8 telescope is long and heavy. Tube length is 22” long, although, still shorter than many longer focal length telescopes. It weighs a heavy 18.5 lbs and this is tube weight alone with the multiple dovetail bar and bases. It’s best to get a heavy-duty mount to handle all the poundage you’ll be loading it up with.

What Type of Mount is Recommended for the Orion Astrograph?

Only you can decide what specific mount will work best for your needs, but it must have a Losmandy dovetail mounting system. GoTo with equatorial movement will be the best choice for imaging. You’ll want to spend a good deal of your budget on a high-quality and heavy-duty mount to handle the many hours of long exposures and imaging that the Astrograph is capable of.  

Is the Orion 8” F/8 Ritchey-Chretien Astrograph Collimatable?

Yes! Both the secondary and primary hyperbolic mirrors can be collimated. Ensure you perform the star test procedure to confirm collimation accuracy. Instructions to collimate the Astrograph are outlined in the included user manual.

How to Clean the Astrograph Telescope?

The Orion 8 Astrograph does not have user-serviceable parts, and Orion expressly indicates that any self-measures to disassemble the scope will void the warranty. Don’t attempt to clean the mirrors. Use the dust cap when the scope is not in use, and keep it sheltered from the elements. This may a good excuse to purchase or DIY build a dome for your backyard. Consider it an investment as you could justify buying a much bigger telescope in the future too!

Conclusion

If you know your stuff about telescopes, you won’t be disappointed with the Orion 8” F/8 Astrograph.

We’ve gone over what it provides, how it will perform, and what to expect. What mount, accessories, and imaging gear you choose will decide the rest.

To really give the Astrograph a run for your money, get under some dark skies and be ready to be impressed.

Pictures taken through this scope deserve to be shared, so don’t forget to post your proof that you’re a proud owner of this imaging champ.

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