If you think you’ve seen the optical tube before, you have - it’s the same Chinese-sourced tube sold by other retailers. The optics are decent at low powers, but as you climb in magnification, the fast f/5 focal ratio optics start showing some aberrations - there’s false color (purple halos) around brighter objects, and as you get near 100X, image quality starts to break down. The moral: Take it easy on the magnification, and you’ll be OK. Even without pushing it, you can still easily see the rings of Saturn, four moons of Jupiter, and a lot of lunar detail. And aberrrations aside, the little NexStar 80 is a fun low-power rich field telescope. You’re going to have a lot of fun looking at the Pleiades, the Double Cluster in Perseus, the Andromeda galaxy, the Orion Nebula, and dozens of other objects. The telescope’s Goto system will be instantly familiar to anyone who’s initialized a NexStar (or Meade’s similar Autostar system. ) If you haven’t done this before, the scope needs to be told some basic information: the current time, date, location on the planet, etc. Then you center two known stars to the best of your ability. The scope takes over from there, automatically slewing to the desired object, and keeping it in the field of view as the earth rotates. Mostly it works well, but there are a few minor glitches here and there. The battery pack has a loose connector, which is prone to falling off, forcing you to reinitialize (hint: try attaching the pack to the fork arm itself using velcro. ) The computer sometimes takes the "long" way around, strangling itself with its own cord. And the unit’s light weight - only 11 pounds - won’t break your back, but it’s so light that any accidental bump (easy to do in the dark) will knock the scope out of alignment, forcing another reinitialization. The hand held controller contains a wealth of information. The 4,000 object database is probably optimistic for such a small scope (you won't be able to actually see all those objects), but it’s a nice touch, and besides, silicon’s cheap, right? In fact, one of the fun things you can do with a scope like this on a rainy day is to do a "fake" initialization indoors (yes, even in the daytime. ) Then, just start pushing buttons on the controller and read all about the objects in the sky. So, in the end, what we have here is a nice telescope that offers good value for the price. No scope in this price range is perfect, of course, but there are few other options in this price range. Meade’s ETX70AT is similar to the NexStar 80GT. If you‘re looking for more light gathering ability, go with an Orion XT6 or XT8. If you like the NexStar system but want a more serious telescope, consider saving up for Celestron’s NexStar 5i. -Ed Ting Pros: Light, compact, versatile, and inexpensive On-board computer makes finding objects a snap Good at low power Cons: Optics only so-so at higher powers Cords tend to tangle Relatively small aperture (80 mm).

High Transmission Water White glass. These three components of the StarBright XLT coatings result in one of the finest coatings available.

Even if you can't find the location of two bright alignment stars, NexStar will find them for you using the "go-to" hand control that can be mounted on the fork arm for hands-free operation. The hand control is fully computerized, and it has red back-illuminated buttons that help retain your night vision. Just enter the date, the time, and your location, and the NexStar will align itself to the necessary stars. The hand control includes a built-in RS-232 communication port allowing you to control the NexStar from a computer and use popular astronomy software (like The Sky, which is included) for point-and-click slewing ability. Finding objects is easy with the Star Pointer finderscope, which is like having a laser pointer that you can shine directly onto the night sky. Just align the red dot seen through the Star Pointer with the desired star in the sky. Additional features include:Star diagonal-1. 25 inchesVisual back-1. 25 inchesHeavy duty base with rubber feetRS-232 port to communicate with a PCNine available slew speedsIncredible 6. 5-degrees-per-second slew speed Powered by standard AC adapter or eight AA batteries (not included)Mounted on a sturdy metal base, the NexStar 5 sits securely on any flat surface and has three rubber gripping feet for vibration suppression and traction. Weighing under 18 pounds, it is extremely portable.

Once the telescope's computer has been initialized to the sky, any of over 4,000 targets can be selected from the onboard database by using the hand controller. Choose each target by scrolling through menus while reading object names and information from the controller's LCD readout. Large, softly backlit control buttons are easy to see and press, even when wearing gloves on cold nights, although I have found that the brightness of the LCD readout tends to drop off as the temperature approaches freezing. In practice, the NexStar 4GT's goto system works adequately provided it was properly initialized and has a fresh set of batteries. Although the motors are noisy when slewing from object to object, the selected target is usually within the field of the 25-mm eyepiece. Once in a while, however, the telescope will go into a "death slew," seemingly spinning around aimlessly. To bring the scope back to its senses, press one of the direction keys, then "Enter" to try again. Sometimes, this will happen when the batteries are running out of power, for which the NexStar 4GT has quite an appetite. A fresh set of batteries will be fully drained after only a night's worth of use. To save the expense of new batteries every clear night, buy the optional AC adapter or Celestron's Power Tank, which allows portable operation. Optically, the NexStar 4GT has its pros and cons. Images are rather dim due to the small aperture, although most that I have examined seem to give reasonably sharp views. The Moon and brighter planets certainly put on a good show. Jupiter shows two or more belts and Saturn's rings display Cassini's Division, although not as clearly as through a 4-inch refractor. Double stars, such as Castor in Gemini, are cleanly split. Like the Meade ETX telescopes, the NexStar 4GT has a built-in "flip mirror. " By turning a small knob, an internal mirror diverts light either up through the star diagonal into the eyepiece or directly through an opening where a camera body can be attached for photography. The NexStar's mounting, however, is really only suitable for short exposures of the Moon or terrestrial scenes. One reason why longer exposures are not recommended is the accuracy of the motor drive's tracking. While aiming precision is adequate, the telescope does not track the sky as accurately as some other telescopes, including the ETX. Even after the telescope has been initialized precisely, objects tend to drift out of the field of view, requiring users to press the direction buttons on the hand controller to keep up. Overall, I'd judge the Celestron NexStar 4GT a good second telescope for someone who is looking for a "grab and go" instrument for quick viewing sessions. Although slightly larger than the Meade ETX90EC, its small aperture still limits it to brighter objects only. If money permits, I would recommend the Celestron NexStar 5i or Meade ETX125EC, both of which have better optics and larger apertures. -Phil Harrington, author of Star Ware Pros: Compact, light weight design Goto computer control Ease of setup Cons: Small aperture Short battery life Poor tracking precision Noisy motors.