Celestron NexStar 8SE has a phenomenal optical tube.
Review
NexStar 8SE has been around for 40 years now, and is holy among astronomers, for a valid reason; the optics are perfect. They are a show-off, almost. They are what an optical design can be.
NexStar 8SE – Orion Mini Deluxe Pro AutoGuider Package
Optics
10
203mm(8″) Aperture
2032mm Focal Length
f/10
All-Rounder
NexStar 8SE is an 8″ Schmidt-Cassegrain. The optical path is near 2000mm(80″) long, and the beautiful thing is, the optical tube is merely 432mm(17″). You can easily carry the optical tube under your arm, or with your hand.
The optics don’t have defects such as diffraction spikes and chromatic aberration. These are major problems with reflectors and refractors, and with Schmidt-Cassegrain’s they are non-existent.
The StarBright XLT coatings provide near %98 light transmission. If God himself came down and built a telescope himself, the transmission would be %2 better.
You might have understood why the optical design is worth that much praise. The Schmidt-Cassegrain design fits powerful, faultless optics inside a small space.
Planetary Performance
All of the Solar System is within reach for the NexStar 8SE. The longer optical path makes the telescope easier to focus at high magnifications and gather more detail from Jupiter, Mars, Saturn, Venus, and The Moon. The farther and smaller planets, Mercury, Neptune, Uranus, Pluto(Never forget Pluto.), are hard to observe with any telescope.
NexStar 8SE is a planetary performer at its core.
Jupiter shows it many stripes with their unique beige-brown-reddish colours. The Great Red Spot is clear and sharp, and its Galilean Moons show themselves as bright disks instead of tiny spots.
Saturn shows a spectacular amount of detail within its rings. The Cassini Division is, and a few of its moons are observable. Titan, the largest one, is the easiest one to catch a glimpse of.
Mars and Venus look detailed with NexStar 8SE since their orbits are next to Earth’s. The surface detail on Mars is visible as black and white stains. The reddish nature of the surface is clear, as well. Venus doesn’t show any surface due to its thick atmosphere, but the unique yellowish colour of the planet is clear. And, its phases are easily observable.
Neptune and Uranus show themselves as blueish dots. It is not easy, but you may get a glimpse of their moons in perfect conditions.
The Lunar Surface is mesmerizing to observe with NexStar 8SE. This due to the fact that the optics are built for gathering detail and getting closer. And there are no colour inaccuracies.
As a result, countless creatures and mountain ranges on the Moon show themselves as if you were orbiting the surface. The optics are able to get so close to the Moon you feel like you are on an Apollo Mission.
The planetary performance of NexStar 8SE is fantastic.
Rho Ophiuchi – Cygnus – NexStar 8SE – Joel Frohlich
Deep Space Performance
Deep space performance, in contrast to the planetary, is disappointing at first. This is due to the focal ratio of f/10. The field view is too narrow.
The optics desperately need a focal reducer for deep space.
To solve this problem, a focal reducer is almost necessary. It will widen the field view for large objects such as the Andromeda Galaxy.
With a focal reducer, deep space performance rises to impressive levels. Star clusters are great targets since they cover smaller parts in the night sky, but nebulas and galaxies are a joy to observe as well with NexStar 8SE. The performance is comparable to an 8″ reflector, and that says a lot.
Is Astrophotography possible with Celestron NexStar 8SE?
With the accessories that come with the telescope, serious astrophotography is not possible, and that is assuming that you have a DSLR camera.
With the NexStar Mount long-exposures are impossible.
This is due to the nature of the mount. It is an altazimuth, which means it moves in an up-down motion. It won’t take long before the image gets blurry.
You need “equatorial” motion for astrophotography, which counters the Earth’s rotation perfectly.
With the NexStar Mount, 1-2 minutes of exposure is possible, which limits you to The Moon, Jupiter, Saturn, Mars, Venus and bright star clusters. As long as the object you are trying to image is exceptionally bright, less light will be required, and you will be able to get a detailed photograph.
Solutions for Deep Space Photography With Nexstar 8SE
There are two ways to counter the astrophotography problem. The first and most obvious one is to get a motorized EQ mount. Those range from 300$-2000$.
Or, you can get a HyperStar 8. This is specialized equipment from a company called Starizona, and it replaces the secondary mirror(the one on the front) with a camera. This reduces the focal ratio to f/2 and provides a delightfully wide-field view. As a result, the required exposure times drop to 1-2 minutes, which is around what the NexStar Mount is capable of.
One other solution would be Celestron’s Equatorial Wedge, which tilts the telescope so that it can follow Earth’s rotation. It is a cheap and smart solution that works well.
Mount
8
Slightly Unstable
Reliable Accuracy
No Built-In Battery
2″-Steel Tripod
The NexStar Mount has its problems. It is safe to say that it is the weakest part of the whole package.
Sturdiness
The mount is barely enough for the 8″ optical tube.
But, at 8″ the mount starts to struggle. Tiny movements at high magnifications occur, and they are more noticeable as you go for higher powers.
The same can be said for the tripod. It is a 2″, steel model, which is perfect for 6″ and lower optical tubes. And, like the mount, with 8″ optical tubes, it is slightly unstable.
The stability problem is not a deal-breaker, but it is there and won’t be cheap to solve.
The Battery Problem
The other major problem is the lack of a built-in battery. At first, I thought this was due to the lack of technology, but later I’ve learned that this is for decreasing the cost. The Evolution line of Celestron comes with a built-in battery for a higher price tag.
The battery slot that comes with the telescope is able to contain 8 AA batteries. They don’t last a good 3 hours. They are more of a back-up than a real power source.
In the end, you will have to acquire an external power source, which damages the whole “GoTo” aspect of the telescope. Although in time you start to accept the fact that there is no battery, it will always be a burden for the NexStar Mount.
Is NexStar Mount Reliable?
The reliability aspect of the NexStar Mount is an impressive achievement of Celestron.
Firstly, they have great customer service. So if you have a Celestron Customer Service near where you live you can be sure everything will be fine. In fact, I would recommend getting a computerized telescope only when you have a customer service within range. Otherwise, it will be a pain to get the telescope fixed if it breaks down.
Secondly, the motors rarely break down. In fact, if looked after carefully, they work perfectly for 6-7 years or more. There is nothing to do but to congratulate the engineers at this point.
The Software
The hand controller feels old.
Using the hand-controller feels like time traveling to 90’s. The alignment procedures work fine, and the GoTo capabilities work well. But there is nothing more to it. You enter the object, and the optical tube follows it.
The SkyPortal App, on the other hand, feels much more modern. But it only works with Celestron’s WiFi Adapter, which is not known for its reliable connections.
StarSense
Celestron recently introduced StarSense, and it is an achievement in astronomy equipment. The camera auto aligns the telescope and works surprisingly well. But, it costs 400$, which is as much as a real DSLR Camera.
In the end, the choice is yours, but NexStar 8SE is around the price range that can be worth an investment as costly as StarSense.
Accessories
7
25mm Plössl Eyepiece
Red Dot Finder
1.25″ Focuser
1.25″ Diagonal
Celestron kept it simple with the accessories, and I think that’s a smart decision. At this price range, the astronomer should be able to decide what kind of a path she/he is going to take with the telescope.
A 25mm Plössl eyepiece is included for low-power use and a cheap red dot finder as well. The eyepiece is OK for the beginning, but the finder needs an upgrade. It is nowhere enough for an 8″ Schmidt-Cassegrain. An 8×50 would be a decent starting point.
There is also a 1.25″-star diagonal. It is optically at a decent level and great for high-powered eyepieces. But a2″-star diagonal is almost necessary. The optical tube already leans towards high powers and a 32mm-2″ eyepiece is a great antidote for that.
The focuser is built-in. It is not as precise as metal Crayford models that you would get with reflectors at this price range, but it doesn’t bring up significant problems. A little more precision at high magnifications would be nice, though.
Recommended Accessories
While a 2” star diagonal might be a good idea for the 8SE, choosing one can be complicated, as can a 2” low-power eyepiece to go with it – and the less-than-steady 8SE mount works best with as little extra weight applied as possible. The Explore Scientific 24mm 68-degree (85x) provides a wider and sharper view than the 8SE’s included 25mm E-Lux Plossl eyepiece, the 15mm UWA provides a sharp medium-power view at 135x, and the 8mm Starguider provides 254x, which is about all that the 8SE can handle under most viewing conditions.
Drawbacks
Unstable Mount
Needs Upgrades
Cheap Finder
The mount can handle the optical tube, but barely. A longer dovetail bar and stronger connections would be appreciated.
There are hundreds of dollars to spend to achieve the potential of NexStar 8SE. And if you are going for astrophotography, hundreds of dollars more.
The finder is almost useless.
Conclusion
NexStar 8SE is one of the rare, expensive models that can meet the expectations. There is one reason for that; the optics. They are impressively powerful in a delightfully small space.
There are hundreds of dollars more to spend for the NexStar 8SE, and the mount is not ideal. But, NexStar 8SE rightfully earns the title “legendary”.