The Optical Tube of Evolution 8
As the name of the telescope suggests, the NexStar Evolution 8 is an evolution from the older line of Celestron telescopes. The Evolution 8 is the latest of Celestron’s 8” Schmidt-Cassegrains known as the C8, with design roots tracing back to the 1960s and the original orange-tube C8 having debuted in 1970. Apart from updates to the coatings and manufacturing process, the C8 has changed little in terms of performance or design in the past 50 years – though Celestron does sell an EdgeHD C8 in various incarnations which have improved field flattening for astrophotography and ventilation holes. The Evolution 8 is available with an EdgeHD upgrade and StarSense autoalign bundle but we don’t see a reason to shell out the funds – the EdgeHD won’t perform any differently for visual use and the StarSense is unnecessary.
The C8 is an SCT or Schmidt-Cassegrain telescope. The SCT telescope uses a corrector plate in the front, an extremely fast f/2 primary, and a convex secondary mirror. The advantage of an SCT telescope is that it is extremely short thanks to the fast primary mirror, but the actual focal ratio is f/10 after reflecting off of the secondary mirror.
The Evolution 8 is as the name suggests an 8” or 200mm telescope. This is an ideal size for beginning astronomers or those who want something portable yet with a decent aperture. 8 inches is not likely to reveal great detail on dimmer objects, especially galaxies, so this telescope is more suited to nebulae, star clusters, planets, etc which are all relatively bright objects.
The telescope has a focal ratio of f/10, making the focal length 2000mm. This is a very long focal length for such a small telescope and is a great feature for planetary observing. This can make it tricky at times for wide field observing. But for most targets, this is not a problem.
The C8 has built-in HyperStar compatibility. This means that if you purchase Starizona’s Hyperstar corrector, you can remove the secondary mirror and put the Hyperstar in its place to image at f/2 with a cooled astrophotography camera. Not all cameras will work with this configuration, however – monochrome cameras with filter wheels won’t reach focus and you want to be careful to not obstruct the aperture with a large camera housing. Additionally, a HyperStar costs more than the entire telescope, and isn’t that useful unless you put the C8 on an equatorial mount.
The Evolution 8 includes two Plossl eyepieces, a 40mm, and a 12.5mm. These are decent, but being included eyepieces they are not of great quality. Being Plossls, they have a small apparent field of view, which means you will only see a small circle when looking through the eyepiece. Eyepieces with a larger field of view are typically more immersive, as the area filled with light is larger and takes up more of your sight. The included eyepieces may be able to get you started observing, but you would most likely want to upgrade fairly soon after you purchase the scope.
The NexStar Evolution, as with all the NexStar telescopes, is meant for use by visual astronomers; as the mount is an Altitude-Azimuth (Alt/Az), you will most likely have a difficult time trying to take images with it due to the effects of field rotation. For visual use, Alt-Az telescopes are favored because of their ease of use, and simple directional pointing. The Alt-Az type mount also does not require polar alignment and only requires a 2 or 3-star alignment to be able to use the telescope, slew, and track.
The mount features built-in Wi-Fi. This is one of the only all in one telescope systems to be able to be slewed from wifi WITHOUT an adaptor! What this means is that you will have an incredibly easy time being able to connect to the mount without any troubles or messing around with adapters or complicated software. You can control the mount from any mobile device that has wifi from Celestron’s app, SkyPortal. SkyPortal is based on the awesome SkySafari app, which we highly recommend, and as such it includes 100,000 targets, plus the ability to slew to any point in the sky, while also being tied in with the excellent planetarium software.
The mount includes a lithium battery inside, which means there is no need for you to buy a typically very expensive external battery, and will last far longer than many of the lead-acid batteries sold for powering telescopes with. The battery also can charge USB devices, which can be useful if your device would not last a whole night.
The Nexstar+ hand controller includes over 40,000 objects in its database, an internal time clock which means that you do not have to enter the time and date every time you start up the mount if you choose to enable it. The pointing accuracy of the mount after a 3-star alignment is also excellent. The controller includes 9 slew rates for intricate and accurate slewing and pointing which means you can go from rate 9, which moves the mount several degrees per second to 1, moving at half the speed of the stars.
Should I buy a Used NexStar Evolution 8?
If the price is reasonable, a used Evolution would be a great telescope. Be sure to check that the built-in battery, WiFi, and of course the electronics work. Since these telescopes haven’t been around for very long, there’s little concern about any major electronic failures, but as time goes on you should be more wary of components – particularly the battery – ceasing to work on older models.
The NexStar Evolution 8 is far from the cheapest scope we’d recommend. At as well as far below its price range, there are a lot of other options which offer you different capabilities:
- The Orion XX12i’s larger aperture makes for far brighter views of deep-sky objects and improved views of the Moon and planets, though it lacks the convenience or full GoTo of the Evolution 8.
- The Sky-Watcher 10” GoTo Collapsible offers a bit more aperture and a lower price tag than the Evolution 8, with the same GoTo and built-in WiFi features.
- The Celestron NexStar 6SE is a bit smaller and more portable than the Evolution 8, and at a much lower price tag – albeit lacking in as many features.
Aftermarket Accessory Recommendations
What can you see?
The Evolution 8’s moderate aperture and long focal length mean it’s not likely to be the best on deep-sky objects, but it still packs a fair amount of punch. Viewing spiral arms in many of the bright galaxies and beginning to delve into the Herschel 400 list of objects is no problem under dark skies, and even from a city the Orion Nebula will look magnificent and you’ll be able to resolve the brighter globular clusters like M13 and M22 into swarms of stars. The Moon and planets look great – you’ll have no trouble picking out the cloud belts on Jupiter and Saturn along with their various moons, and of course the eclipses and transits of Jupiter’s – along with of course the phases of Venus and Mercury and a few dark spots on Mars. Uranus and Neptune are bluish dots, and Neptune’s lone large moon Triton is faintly visible under good conditions.