The dread of collimating mirrors can be a turn-off, especially for a beginner, but the XT8 addresses this task admirably.įirst, the instructions walk you through the process clearly with good illustrations. Looking at the lunar surface itself, the scope delivered, offering sharp, high-contrast views of crater Gassendi and the rilles on the floor of the Mare Humorum.Īlthough a few minor shortcomings mean it falls slightly short of getting top marks, the XT8 PLUS is a well thought-out package that offers a good option for a first scope.Īll the accessories essential to getting started are included, while the detailed instructions will make the learning curve much easier for a first-timer. When observing objects near the Moon or a streetlight, these internal reflections severely reduced the contrast. When slewing towards a bright gibbous Moon we noticed some glare in the eyepiece: this was due to light reflecting off the internal surface of the telescope, meaning it was not adequately blackened. Observing deep-sky objects is a strength of Dobsonians and this one was no exception, but the next test was the Moon. Unfortunately, the 1.25-inch Barlow lens cannot be used with the 2-inch DeepView eyepiece. Zooming in with the 10mm Plössl, the view was still sharp and well-defined, so we tried out the supplied 2x Barlow lens.Īt 240x magnification, the view remained sharp in moments of good seeing. We got an excellent view of the Ring Nebula in Lyra – small, bright and glowing faintly in the middle. The very diffuse Triangulum Galaxy is a challenge under light-polluted skies, but the XT8’s 8-inch aperture succeeded in showing its faint glow in the 28mm DeepView eyepiece. This is a common problem and easy to fix, though it’s not mentioned in the instructions. We discovered that this was due to the primary mirror clips being over-tight and deforming the mirror slightly. Switching to the 10mm Plössl eyepiece at 120x magnification, the diffraction rings were concentric but elongated, suggesting that some astigmatism was present in the optical train. The 28mm DeepView eyepiece was reasonably sharp, but showed astigmatism towards the edge of the field. It is a little plasticky, with a small screen and slightly elongated red dot, but it still allowed us to locate our target. Turning skywards, we slewed to Vega using the red-dot finder supplied, the Orion EZ Finder II reflex sight. However, there is no handle on the tube for guiding the scope, which would have been a welcome addition. The scope is well-balanced and even when we inserted our own heavy eyepieces only a little tension adjustment was needed to stop the front end from tipping. The mount’s axes were adequately smooth to slew the scope and track objects at high magnifications.
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