Product Description

The Advanced Series telescopes offers features and quality that serious amateurs can appreciate. These scopes come on heavy-duty German Equatorial mounts with ultra-sturdy 2" stainless steel legs and center tray for superior rigidity and vibration dampening. These telescopes are carefully designed for the more advanced astronomer and feature exquisite optics on a heavy-duty mount. The optics of this telescope are made to exacting standards, with high quality materials to ensure top performance. The C4-R 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 C4-R is mounted on the CG-4 mount. The mount features precision gears for extremely smooth motion. A counterweight, latitude scale, setting circles, and slow motion controls on both axes are standard, so you have a fully loaded telescope right from the start.

Product Details

• Amazon Sales Rank: #6766 in Camera & Photo
• Brand: Celestron
• Dimensions: 11.80" h x 16.80" w x 38.00" l,

Features

• 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 Review
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

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.

Customer Reviews

bought too quickly
This was the first real telescope I purchased. The product description fits, but, as I found out later, I should have started with a good pair of binoculars. The mount is the culprit that caused me to give the telescope a 3 rating. It isn't the quality I expected from Celestron. After carefully carrying this heavy (equatorial mount) scope in and out of my van numerous times, there is evident play in the mount. Other than that, I have seen beautiful views of Saturn, Jupiter and Orion Nebula. Another problem is straight up viewing, virtually impossible. Would recommend a good pair of binoculars (7X50 or 10X50) and a dobsonian mount at least 8 to 10 inches for starting astronomers. As you may or not know, what you see in this telescope (as all others) will not look like the beautiful pictures in astronomy mags and books. It takes a lot of viewing to start dectecting any colors, and the size of the object won't be very large, other than the moon. I know I am adding a lot about astronomy, but I learned the hard way, join an astronomy club,and try out all the scopes they offer before you commit to something that will collect dust. Clear Skies, don

Low-Contrast Detail and Portable Too
This is a good scope for the price. It provides refractor-sharp views of the Cassini division in Saturn`s rings and cloud bands as well as the shadow of the rings on the planet. I`ve also seen as many as 8 cloud bands on Jupiter and the two reddish equatorial belts. The bands look like they`ve been colored in with a very sharp pencil point. The 4 Galilean moons are easily seen and, with good seeing, the Great Red Spot is also visible. Also, views of the moon are contrasty and filled with lots of details. Mercury, the phases of Venus, Mars, 100`s of deep space objects, etc., are also easy targets. For instance, the Orion nebula is a spectacular sight with it`s greenish glow.

Most images are extremely clear, sharp and bright with almost no spurious color on bright objects. One has to sometimes look for the spurious color to see it.

IMHO, the mount-tripod seems to be fine even for high-power views if everything is tightened up all the way and vibration suppression pads are used. In fact, this makes for a very portable set-up which can be carried around pretty easily and can be ready for use at a moment`s notice.

Conclusion: This scope excels at showing low-contrast details. This is one of the refractor`s most superior features and is one of the main reasons why they often make better planetary scopes than other types of scopes much larger. The C-102HD is no exception!

Great buy
For the money this telescope is hard to beat. The OTA is well made; the 102mm Achromat being housed in a adjustable metal lens cell. The tube has three internal baffles and has a nice focuser which will accomadate 2" eypieces. My focuser was originally rather sloppy but after tinkering with several screws it tightened up nicely and is now quite serviceable. It also includes a 5.5" removeable felt lined aluminum dew cap. The 30mm finder scope is to small and it would be good to replace it with 50mm. The equatorial head is solid and well matched to the OTA. It has the standard(rather small)setting circles with a vernier. The slow motion controls work fine with no backlash although the locks have to have a slight amount of tension otherwise there may be some slippage. It's also supplied with two conterweights one large and one small. The small weight tightend all the way to the end of the counterweight shaft leaves the scope perfectly balanced. The larger weight is to be employed if photography is desired. I added the single axis clock drive and it tracks well. Again there has to be a slight amount of tension(via RA lock)on the RA axis or there will be some slippage. The weakest point of this model is the aluminum legs. Aliminum has the advantage of being light but has a very low dampening coeficent. Thus, focusing at higher powers can be a challenge. My remedy to this problem was to add a JMI electronic focuser. Focusing is a breeze now as I don't have to touch the OTA when adjusting. Another alternative used by some is the addition of wooden tripod legs. The scope is supplied with a nice 20mm Plossl; But figure on buying a couple more plus a barlow as this scope handles 200mag. well. Optically it does very well on the star test with only a slight amount of spherical abberation present. Ronchi grating test shows sraight lines in and out of focus. There is some false color, as to be expected from an achromat, around bright objects. All and all a very nice package. I would have given a five were it not for the tripod. Keep in mind this is a telescope best used for planetary use and double star splitting. Deep sky object are best served by more aperture. So if that's your fancy consider a "light bucket"(Dobsonian). I have heard of some cases of people getting poor optics with this scope, but that seems to be the exception not the rule. So if that happens to you, send it back to the factory till you get a good one.
Cheers.