Celestron C4-R 102mm Refractor Telescope

Celestron C4-R 102mm Refractor Telescope Review

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Celestron C4-R 102mm Refractor Telescope Feature

• Refractor telescope for serious astronomers and terrestrial observers
• Rigid German equatorial mount for following objects
• Slow motion controls on both axes object
• Magnification: 241x
• Objective lens: 102mm

Amazon.com Product Description The large aperture of the Celestron C102HD Telescope gives you clear images of the lunar surface, Jupiter's belts and moons, and the rings of Saturn, as well as hundreds of deep-sky phenomena like nebulae, galaxies, and star clusters. In addition to viewing the sky, you can use the C102HD for terrestrial observation; use it in your backyard or take it out in the field for close-up views of your natural surroundings.

Refractors     This is a refractor telescope. Refractors (also known as a dioptrics) capture light with a lens at the front of a long tube and send it to an eyepiece at the other end. They look, in other words, just like what most people think of when they hear the word "telescope."     Refractors offer--potentially, at least--the cleanest images of any telescope design. They are simple and reliable (the sealed tube is maintenance-free), and are good for both celestial and terrestrial viewing.     Read more about different telescope designs in our buying guide

This telescopes is carefully designed for the more serious astronomer and terrestrial observer and feature exquisite optics and precision, heavy duty mounts. The optics are made to exacting standards, with high quality materials to ensure top performance. It offers a 63% increase in image brightness over 80mm models, with the larger aperture delivering incredible images of the moon; Saturn and its ring structure; Jupiter and its belts; and hundreds of deep-sky objects, including galaxies, nebulae and star clusters.The altazimuth mount is easy to use and has slow motion controls on both the R.A. and DEC. axes. These controls are on flexible cables, to allow for quick and easy pointing and tracking.For terrestrial use, you can enjoy views from your own backyard or take your telescope out in the field to enjoy the natural environment, up close.The C102-HD is mounted on the CG-4 mount, a very rigid German equatorial mount. A counterweight, latitude scale, setting circles and slow motion controls on both axes are standard.

Moon viewing 101
The moon is often one of the first celestial objects a beginner will look at through his or her telescope. Here are a couple hints for you once you get your hands on your new C102HD.

Often, it is tempting to look at the Moon when it is full. At this time, the face we see is fully illuminated and its light can be overpowering. In addition, little or no contrast can be seen during this phase. One of the best times to observe the Moon is during its partial phases (around the time of first or third quarter). Long shadows reveal a great amount of detail on the lunar surface. At low power you will be able to see most of the lunar disk at one time. The optional Reducer/Corrector lens allows for breath-taking views of the entire lunar disk when used with a low power eyepiece. Change to higher power (magnification) to focus in on a smaller area. Choose the lunar tracking rate from the NexStar's MENU tracking rate options to keep the moon centered in the eyepiece even at high magnifications.

The Celestron C102HD telescope is regarded as a major bargain for good reason. Instead of computerized bells and whistles, you get the solid optical performance of a full sized four-inch achromatic refractor combined with a serviceable German Equatorial mount. Experienced observers frequently recommend the C102HD to beginning astronomers for one simple reason: it delivers great views of the planets.

How great are the views? In side by side tests, the C102HD consistently showed better contrast and more detail on Jupiter and Saturn than my five inch Schmidt-Cassegrain. On a night when my C5 showed five or six cloud belts across the face of Jupiter, the C102HD showed seven. On Saturn, when I push the magnification to 200X, the Cassini division is crisp, I see cloud belts on the planet; I see shading in the A and B rings, and even glimpse the Crepe ring. When looking at the star Epsilon Lyrae, the famous double-double, the C102HD showed me four crisp bright beads of light, without the bright diffraction rings and scattered light that I see in my C5.

One drawback: the CG-4 equatorial mount included with the C102HD is only barely adequate to support a forty-inch plus telescope. I found that it was better to set up on grass or gravel and leave the tripod about a foot short of full extension--this significantly reduces the vibration problems that otherwise trouble this mount.

What accessories would I recommend? Adding a CG4 motor drive significantly increased my viewing pleasure by allowing the telescope to track for long periods without my touching the controls. As with any equatorial mount, you need to point the Polar axis at the North Star, Polaris, for the tracking to work properly (don't worry, this is all explained in the manual). As for eyepieces, the included 20mm plossl eyepiece gives a magnification of 50X and a one degree true field of view. You'll want a 32mm eyepiece to take in the full view of star clusters like the Pleiades and the Double Cluster in Perseus. The Ultima 7.5mm is ideal for high power views of Jupiter and Saturn. I usually suggest a good star chart with any telescope, but for viewing the planets, a subscription to Sky and Telescope magazine might be even more useful; the planets, after all, move from one month to the next! --Jeff Phillips

Pros:

• Solid optical performer
• Great views of the planets

Con:

• Barely adequate mount

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Customer Review

Jul 24, 2011 05:18:33