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Celestron C8

Posted by Ed Moreno   04/27/2006 12:00AM

Celestron C8
Celestron C8

The Celestron C8 (And to me the Meade 8” SCTs) are often charged as being “Good all around scopes.” This gives the impression that they aren’t really great at anything. But “Good” and “Great” are relative terms, and in my experience, the universal yardstick in telescopes is “Price.” There ARE some other important factors such as packaging and aperture, though these are not necessarily coupled together in any way anymore. It is VERY easy to spend FAR more money per inch of aperture, but in the end, given reasonable optical quality, my experience is that aperture is probably one of the single most important attributes on how good a telescope will perform.

Allow me to present a short discourse with respect to my personal view on aperture. I live in sky conditions typical of that of many amateurs today, and that means light pollution and less than excellent clarity. Under such conditions, I find that the 8” aperture is the minimum aperture that I can use under these conditions that actually satisfy me. I have not found any scope smaller than 8” of aperture that is capable of offering truly rewarding viewing. I realize this is a personal opinion, but at the same time, I know or have heard of a GREAT number of people that started with smaller scopes, ultimately to move up to a telescope in the 8” to 10” range. I have also heard of people starting with small telescopes and being turned off because nothing was impressive in their small scopes, so they left the hobby. At the same time, I have recommend 8” SCTs to several people that have been extremely satisfied with them. Going the other way, the step up from an 8” SCT to almost any 10” aperture takes you from something very small and totally manageable to something more demanding to set up and use, and for not nearly as much gain as the difference between say a 4” or 5” scope and an 8” scope. I just found the smaller scopes only useful for wide field viewing, which is not all that great under my sky conditions with anything less than my 140mm Vixen refractor (See, even here, I demand more light gathering than many people will accept for wide field work, shunning 80mm and 100mm refractors entirely as being generally uninspiring to use unless the sky is rather dark).

A good place to start the actual review is on the virtues of the C8’s packaging. This telescope is downright small in terms of physical size. With the diagonal attached, it is shorter than some 4” refractors, and weighs the same. The C8 will fit in the back seat of a car standing on end BETWEEN two adults. It will fit in an airline carry-on bag. It will fit in a closet on a low shelf. It will fit in the trunk of a Mazda Miata. I often hear people comment that they want a small telescope because they are easy to manage, but this is a big telescope in a small package and with aperture being SO important in telescope performance, it seems far more preferable to me to pack whatever space I have available when I travel by car with a telescope that can really deliver maximum performance for the space committed to transporting it.

The small size and low weight are also very easy on the mount. A C8 can be used on an Alt-Az mount, though it takes a reasonably heavy duty one, but no more so than a 4” refractor (except for the f/5 ones that are not so great choices for anything BUT low power observing). But my preferred mount is a GEM. The C8 CAN be used at VERY high powers, and when doing planetary or lunar observing, I just enjoy observing more and I think that I actually SEE more when I use a driven mount. This is because your eye and brain actually work together something like a camera and film does. If you really study an object closely, after 10 or 15 seconds, detail that was not initially evident starts to emerge. When I have used non-driven mounts, I never felt like I could let this image build satisfactorily to get the most out of the telescope before I had to move the OTA. And don’t think this is only applicable to planets. On objects like clusters and globular clusters, intent study unveils countless more stars. So I take ALL of my telescopes on driven mounts. Now I notice that even in the Dob world, people are starting to get tracking platforms, or even starting to mount motors and electronics from inexpensive Go-To mounts on their rocker boxes. It is my belief that the best observers realize the benefits of tracking and are starting to want to get the most out of their giant telescopes, which are CAPABLE of being used at high power, but that are harder to use at high power when they have to constantly be moved manually. So to me, the answer is simple… Get a tracking mount. And it is my opinion the C8 on a GEM mount is one of the greatest all around observing platforms in the marketplace today.

I use my C8 on my Meade LXD55 mount. The mount head rides on a Vixen HAL 110 tripod, and this package is absolutely fantastic to use. Because the C8 is so light, I only need one counterweight, which means that I can carry the mount with counterweight attached (no OTA) to my patio in one trip. I prefer the HAL 110 legs because they fold without having to undo any spreader clamps or anything as the new tubular-leg mounts require. You simply lift the spreader up and the legs collapse in. The HAL 110 is MUCH lighter than the new tubular steel leg tripods, but gives up little in stiffness. The HAL 110 is the best lightweight tripod I have ever owned, and it works beautifully on the LXD55.

With the C8, the tripod does not have to be used fully extended for viewing while being seated in a standard chair. This aids in stability. When I use my Vixen 140 refractor on this mount I have to fully extent the legs to get the eyepiece up off of the ground for viewing at zenith. When you extend the legs, it makes the mount less stable. My Vixen 140 is about the same physical length as a 4” f/10 Achromat. The C8 makes less of a demand on this mount than the 4” refractor I used to own.

The C8 also carries the bulk of its weight at the mirror cell end, which allows it to sit high in the saddle, again improving eyepiece height. But this position also has the added benefit of keeping the mass close to the pivot axis of the mount, which means that it is less likely to start vibrating, but if you do bump it, even when used with something like a Vixen Super Polaris mount, the dampening will be very fast, even without vibration suppression pads.

With the eyepiece located so close to the saddle, you will notice that it does not move through a giant arc when viewing from zenith to the horizon, so this means that you can accommodate much of your viewing with a simple folding chair. This is the only telescope of reasonable aperture that I have ever owned that doesn’t force the owner to get an adjustable observing chair for best comfort. I couldn’t live with my refractor without an adjustable chair, and even my C14 requires one, but I can get by with the C8 on a GEM with a standard height chair for MOST observing.

The C8 focuses by moving the primary mirror. Now I know that shift CAN be a problem with this kind of scope, but it seems to be much more of a problem in the larger SCTs that I have owned. Most 8” SCTs that I have looked through seemed to have little or no mirror shift. My current C8 has none. Though this negative is often mentioned, the benefits of this design are often overlooked. First, there is no draw-tube creep. When I use my refractor with my heaviest eyepieces at zenith (35mm Panoptic, 22mm and 17mm T4 Naglers), I have to tighten the little drag screw on the focuser draw-tube to keep it from creeping down. Then when I change back to a light eyepiece, I have to decrease the drag to get smoother focusing (these light eyepieces tend to be the higher power ones that need more precise focusing). When using these eyepieces with the C8, there is never any drawtube creep, and no need for a drag adjustment. In fact, the focuser knob on my C8 moves with silky smoothness and is the lightest action of any scope I have ever owned except my C5, which moved so smoothly that the knob didn’t seem to actually be attached to anything! Mine has an excellent checkered knob which offers a good grip under all conditions.

As I mentioned earlier, the OTA is short and the mirror cell rides high, so when changing heavy and light eyepieces, the leverage of the OTA on the mount head is much less, meaning that if you use a good GEM with clutches that allow for manual movement (Like a GM8), you can leave the clutches set very loose, and when you change form a very heavy eyepiece to a very light one, the scope will have less of a tendency to nosedive. I had this happen to my 4” APO and my Vixen 140 several times when using standard (non-Go-To) mounts, and while luckily neither actually crashed into the tripod, I started jacking up the clutch tension to feel comfortable that it wouldn’t happen, and this made them a little harder to move manually. Now on a Go-To mount this isn’t a factor because the motors lock the mount axis’s in position, but on a standard GEM, if you like to leave the clutches loose to be able to move the scope manually, then the C8 is a good choice for this.

My C8 is graced with Very nice optics. In fact, the three 8” SCT I have star tested in the last couple of years all had very nice quality optics. One of these was my own C8, and both of the others were Meade LX90s (I am not a brand bigot). All had well corrected optics; all were free of obvious zones, and all showed reasonably smooth finishes. Now being mass produced, lots of people don’t really believe that you can get optics of all that great a quality, but if you look at cars, well, some of the mass produced Asian brands routinely beat many of the most expensive European cars in terms of quality measurements and number of initial defects. Yes, a premium scope will have optics finished to a higher standard of quality, but usually at a FAR higher price per inch of aperture, and in the end, C8 beat almost anything smaller I have ever used on most targets. I will tell you about the exceptions later in the review, but trust me, there were only two places where I though smaller scopes beat the C8.

I use a high quality 2” diagonal with my C8. My low power eyepiece is a Meade 56mm Plossl, and this combination provides a bit shy of 1.38 degree actual field of view at about 36x. That is pretty low power, so if you think that a C8 can’t do wide field work, well, it turns out that it can do a fair amount. Note that using an 8” f/5 Newtonian with a 32mm Plossl will give you a similar field and power, but to get a WIDER field with any QUALITY (meaning sharp across most of the field), you are going to have to purchase expensive eyepieces for the fast reflector. At least this is my experience. I have never used an inexpensive and even mid-priced long focal length, wide-field eyepiece that gave even reasonably sharp wide-field view, EVEN AT f/10! Only my Panoptic 35mm has provided really nice, crisp wide field views at f/6, and using this eyepiece in the 8” Newt will get you to 34x, but with a quite beautiful 2 degree field. But you know what? Of the THOUSANDS of objects visible in the night sky, only a TINY fraction of one percent of them WON’T fit in a 1.38 degree field.

Actually, I find that I use ALL of my telescopes (even the 140mm refractor except during the summer Milky Way) far more at medium and high powers than at low powers. My guess is that I am not alone here. In almost every book I have ever looked at that provided observing impressions of celestial objects, in the VAST majority of cases, medium and high powers are given as the “Best” power for viewing this or that object. Check it out… Most often, I see things like “Best viewed at 75x. And here is the real important part. In moderate light pollution, the appearance of most objects gets better using higher powers. To me, “High power” really starts at about 175x, because that is minimum I like to view solar system objects with. But a great number of deep sky objects also show more detail at powers like this. Now the C8 can generate high powers using inexpensive and comfortable to use eyepieces. A 10mm Plossl will give you 203x, with generous eye relief. Even inexpensive Plossls seem to do well in my C8. My point here is that I think too much emphasis is given to being able to generate wide fields, when most serious observing is done at medium to high powers (where tracking also becomes more desirable).

Here goes the observing report.

I will start with deep sky. Much has been written about the light transmission loss of SCTs. An SCT primary mirror has a light collection area of about 44 square inches, adjusted for the secondary obstruction (beware - many catalogs do NOT adjust for the secondary shading). Given a light throughput of about 72% when used with a coated prism diagonal, that yields an effective light collection area of about 33 or 34 square inches. Now remember that even the cheapest SCTs today come with some enhanced coatings, while the cheapest Newtonian telescopes usually have none at all. Consequently, an 8” Newt is going to come out with equivalent of about 39 inches of light collection. That SEEMS like a big difference, but in fact, it is only barely detectable at the eyepiece in limiting magnitude comparisons. The ONLY place where I can see this kind of limiting magnitude difference readily is on Globular Clusters. On most other types of objects, the difference is not immediately apparent at the eyepiece. Now I might mention that if purchased with XLT coatings, and when used with a high transmission diagonal, a modern 8” SCT comes VERY close to a Newtonian with no enhanced coatings. When I say very close, I mean that is within a single square inch of effective light collection. All of the literature that has ever been written that say Newtonian telescopes are better for deep sky should now be taken with a grain of salt. A modern C8 with advanced coatings and high transmission diagonal is going to be extremely close to performance on deep sky objects to just about any fast inexpensive 8” Newtonian made today.

I am starting with globulars because they are one of the best objects for easily seeing the result of using a larger aperture. I am going to include some comparisons to other scopes so someone that may be considering their first purchase will better understand my position on the merits of aperture. Please keep in mind that these observations were made from my central Austin home, which has light pollution probably equivalent to a typical suburb.

The first target I will give an impression of is M13. Simply put, in my observing conditions, NO telescope of smaller aperture has done a better job at resolving this stunning object. The C8 is the minimum aperture that more or less resolves stars down into the core under my typical observing sky conditions. Using a 12mm Nagler (about 170x), this marvelous cluster not only frames beautifully against the background, but provides a lush outer halo of member stars, and gradually condenses down to an almost stellar nucleus. It is radiant. Even first time observers comment on how incredible this object looks in the C8. Now for some comparisons that I hope you might find useful. My Meade 152ED refractor did not quite resolve the core, but it was the only telescope smaller than the C8 that came anywhere CLOSE to offering an exciting view of this object. The MN61 that I owned did poorer on M13. That particular scope did not have advanced coatings and this showed up in light throughput. M13 looked to be midway between the Meade 152ED and the 4” Televue I used to own. That is to say that there was a granular core, surrounded by a nice halo of outliers. The 5” SCT and 5” MCT were actually not all that much better than the 4” refractors. The Televue APO only resolved the bright outlying stars, and the core looked to me to be nebular rather than grainy. The 4” Vixen achromat was almost identical to the APO on this object. In fact, I was totally under-whelmed with this object in the 4” and 5” scopes.

Go north to M92 and the difference is equally apparent. This Globular is a bit dimmer, but the C8 still resolves it. It provides a hint of stars across the glow of the central condensation, but it tails off much quicker than M13, showing a slightly populated stellar halo. But the next best scope on this object, the Meade152ED, struggled to show very many stars across the core, though overall M92 was easy to identify as a Globular. Now I say that because many of the smaller scopes don’t come close to resolving this cluster.

Now transfer these results across the couple of hundred other Globulars in the sky. In fact, of all of these objects, only my C8 and larger scopes are capable of resolving any respectable number. In all, I just was not satisfied with any of the smaller telescopes on this class of target. To see M13 in anything less than an 8” aperture is to miss out on one of the best objects in the northern sky.

For open clusters, the situation is almost identical. An impatient observer or an unskilled one may not notice all that great a difference between a really good 6” refractor and a C8. Here I will use another awesome target, M37. M37 is almost like a loose Globular to me, in that it is a giant ball of stars. The difference is that the distribution doesn’t condense, but rather it is more of a smooth distribution until near the edges. Using the C8 with a 22mm Nagler (about 92X), this cluster is lush with members and beautifully framed against the rich background. Also, the apparent range in brightness between the brightest and dimmest stars is more pronounced than in a scope like the 6”, but the difference is small. The 6” refractor took a bit more power to bring the fainter stars into view, so the cluster didn’t frame quite as nicely as in the C8. This brings me to another point. Shorter focal length scopes are often praised for their wider field capabilities, but in a smaller aperture many of these clusters only really start to show much fainter members when you push magnification. In a smaller scope, to see the same number of stars, you may have to push up the magnification to the point that you can no longer frame the cluster as well as the C8 can using lower powers. In my Meade 152ED, M37 seemed to show a similar number of stars at 137X as the C8 showed at 92X, but the big refractor didn’t frame the cluster against the background as nicely because the higher power reduced the actual field. I encounter this often, where I have to really crank up the 140mm refractor to bring out faint stars, so that I wind up having a much smaller true field to work with than the C8. If I drop magnification in the smaller scope, fainter members start to slip out of view due to background sky-glow. So despite what many people say about the advantages of lower power, my experience is that unless you observer under fairly dark sky conditions, you are likely to actually be able to see many objects better in the larger scope at lower power, allowing a wider true field for framing the object against the background.

On clusters like M36 that don’t contain as many stars, a small scope will often show the shape described in books and such, but a bigger scope will greatly increase the number of faint stars embedded within these more prominent “Pattern” stars. In my C8, M36 contained a handful of stars that were not visible in the Meade refractor, but no scope smaller than the Meade 152ED really makes this cluster come alive to me. But this sounds like I am saying that the Meade 152ED is almost as good for deep sky as the C8. Well, on these showcase objects the difference is actually very slight. But as you move out of the Messier objects and into the NGC catalog, there are hundreds of very faint star clusters that show member stars in the C8 that are only just hinted at in the 6” These same clusters are almost totally invisible in a 4” scope. Of the scopes I have been mentioning, only the C8 collects enough light to start really getting into the NGC catalog

Galaxies don’t respond exactly the same way as star clusters do when comparing them in telescopes of different apertures. This is because for the most part, the main difference you will see is that the angular size of the target will be bigger in the larger scope. Now this isn’t always easy to judge. If an edge-on spiral goes from 6 arc minutes in length in a 4” scope to 8 arc minutes in length in an 8 inch scope, a casual glance at the eyepiece may suggest that the 8 inch scope isn’t doing that much better. If you have field stars in the view to compare it to, it starts to be more evident, but many people might say something like “My 4” refractor did almost as well as that guys 8” SCT on M86.” In fact M86 appears quite a bit larger to me in the C8 than it did in my 4” refractors, my 5” compound scopes, and the MN61. The difference on the Meade 152 was not nearly as noticeable, but careful observation shows a bit more extension in the C8. Now that doesn’t sound like a big deal, but in reality you are starting to see more of the halo glow from this giant elliptical, while in the smaller scope you are really only seeing the bright central nucleus. This is such an important point. A difference of a full magnitude between a 4” scope and an 8” scope when seen at the eyepiece is a really large difference. On many objects, a quick peek may not show a glaring difference, but close, careful scrutiny always starts to reveal nuance that is not visible in the smaller scope.

As with the comparison on open clusters and globulars, once again, the C8 as compared to anything smaller I have owned actually lets you start roaming outside the Messier catalog by showing a great number of faint NGC galaxies.

The more structured Nebulas don’t always show much difference between smaller and larger telescopes. For example, M27 shows basically the same swan silhouette to me in 4” and 8” scopes. But there are a great number of nebulas that start to actually show structure in the C8 that isn’t readily apparent in a smaller telescope. Let’s get started with M42, arguably the finest nebula in the sky. This is an object that looks splendid in ANY size telescope. In my 4” APO, it was a beautiful arc of nebulosity. It looked absolutely fabulous at medium powers, showing a faint gossamer film between the arcs, and the splendid Trapezium blazing in the nebular concentration near the center of the arc. My 5.5 inch refractor was even more breathtaking, starting to hint as some structure in the brightest parts of the nebula at higher powers. The Meade 152ED really started to show quite a bit more of the subtle variation in the density of the bright condensation around the Trapezium. But the C8 can actually start to show whips and mottling at high powers that smaller apertures can’t seem to coax out. Now to actually see these details, I have to work at pretty high powers, on the order of 254x. The smaller scopes just don’t gather enough light to allow this kind of magnification. Trying to use this kind of power dims the structure to such a great extent that my eye simply can’t see it. Once again, this nebula really started to come alive for me in the C8. And speaking of the Trapezium, the C8 is the smallest scope that I have used that can often shows the E and F components. On nights of reasonable transparency and good seeing, I can usually pick them out from the bright background glow with only moderate effort. On a couple of nights I saw them with the 152ED, but they were frequent guests in the C8 view. My C11 showed them on most nights, and my C14 shows them all the time, but the smaller scopes simply never showed them. In fact, in the 4” and 5” scopes, the Trapezium itself is kind of dull looking. They only start to dazzle me in a 6” scope, but the C8 makes them better.

The observing result is similar the Ring Nebula, the Dumbbell Nebula, and many others. The C8 just has that minimum threshold that starts to add enough detail to many of these objects that make them exciting to return to time and time again.

I will wrap up with the Planets and the Moon. Starting with Jupiter, I would say that only two telescopes I have ever owned that were smaller in aperture have bested the C8 on Jupiter. The Meade 152ED was better. The amount of fine detail was simply more pronounced, and seeing conditions seemed to always favor the big refractor. The other scope that was better on Jupiter was the MN61. It also proved quite adept at wringing out subtle detail, though the difference between it and the C8 was very subtle. Now when I do Modulation Transfer Function graphs comparing the C8, MN61, and a 5” APO to one another, the MTF chart says that and optically perfect C8 SHOULD be the winner here. But here is where those slight imperfections in the optics start to have an effect. I have not owned one, but my guess is that any currently manufactured 5” APO is going to have optics finished to an extremely high polish and correction. I know from experience that the MN61 can have almost perfect optics. But as I mentioned earlier, the optics in a C8 usually are quite good in quality compared to those in much less expensive 8” dobs, but they are usually not polished and corrected for Spherical Aberration to the same level of perfection as these more expensive scopes are. As a result, the tiny amount of light scattering that takes place, along with optics that while figured quite well, are not figured quite to the level of perfection that the $4200 five inch APO have been figured to, will take their toll on this target. That being said, my C8 is only a tiny but off from the MN61, but there was no contest between the C8 and the 4” APO I owned. The C8 was closer to the MN61 in performance than to the smaller refractor. Now you can purchase a C8 ON A BRAND NEW MOUNT for less than the purchase price on the MN66 OTA alone, so once again, you are paying far more per inch of aperture. So while you “Get what you Pay for” in terms of optical perfection, in the end, it is all too easy to prevail by simply getting a bigger scope.

On Saturn, the C8’s extra resolution somewhat offset the Meade 152EDs extra contrast to make it almost a wash. Saturn shows a faint hint of the Crepe ring in the C8 and Meade, and the beautiful subtle yellow and smoke colored belts look clearly defined in each of these. The MN61 to me was a bit dim on Saturn meaning that I didn’t find high power observing on this target to be as rewarding. Powers above 225x or so just dimmed the image to much for my eyes, and the extremely small exit pupil caused severe problems with floaters.

On the Moon, the result was similar to Saturn, meaning that the C8 and Meade 152ED were more similar than different, but when seeing is excellent, I think that the C8 actually gives a tiny bit more detail on the inside of craters and on jagged mountain peaks. Seeing favors the big refractor though, and on many nights, it would provide as good or better view on average, but then again, even on bad nights, from moment to moment, you would have little windows where the C8 could do as well.

I will give some thoughts on the often frustrating decision between a C8 and a dob. I know that lots of people think a dob will out perform a C8 on deep sky, but because these scopes generally aren’t finished to the same optical quality as a C8, and don’t employ any advanced coatings, my bet is that the difference between them is not easy to see at the eyepiece, and if you have the money for XLT coatings, my bet is that there WON’T be any difference at the eyepiece in terms of absolute performance on deep sky objects, and you won’t have to deal with diffraction spikes in the view through the C8. You would have to spend a similar amount of money on a premium dob to be able to actually beat the C8 on planets, but the low cost ones are going to have a tough time beating a C8 in the Solar System because of their usually only fair to medium optics. These mirrors are much more likely to have moderate amounts of spherical aberration and rougher figures and this combination can degrade contrast more than the central obstruction of the SCT does.

I will also address the mounting issue of the Dob vs a C8 on a GEM mount. First, the Dob OTA is going to be much more problematic to transport. Next, while the OTA itself only weighs about 17 lbs, when you add the rocker box and ground board, you bump that up to about 41 lbs, which is only a few pounds lighter than a C8 on a Super Polaris mount! If you break down your Dob to carry it out in two trips, well the C8 can be almost exactly as fast to get set up as the Dob. And you get a tracking mount!!!

Sadly, I think that many people think that the GEM mount is more complicated to use than a Dob, and honestly I think it is LESS so. First, let me say that the average novice is probably intimidated by the prospect of doing accurate polar alignment. Wee, here is what I have to say about that: We don’t need no stinking polar alignment! By that statement what I mean to say is that to get the benefits of a tracking mount, your mount only needs to be within a few degrees of the North Star to track an object for many minutes at a time. You simply need to use the latitude scale to set the mount to your local latitude, the when you set the mount down, simply eyeball the Right Ascension axis towards Polaris. Contrary to what a great many people seem to believe, there is no absolute requirement to level a GEM mount. You could hand it from the ceiling, and as long as your alignment is even reasonably close, you will get reasonably good tracking. (Note: It IS beneficial to level the mount if you ARE going to do accurate polar alignment, however this is only because it makes ultra-fine adjustments more intuitive. The reality is that as long as the polar axis is smack dab on the mark, the actual orientation of the mount and tripod is irrelevant. But again, leveling the mount prior to find alignment just makes it easier to GET the polar axis to the mark.) So, you don’t have to be anything even CLOSE to perfect to let the mount track a target. Now when you want to move to your next target, use your chart and a Telrad or your finder scope the same way you would with a Dob, and when you get to the target, simply let go of the scope (assuming that you keep the clutches loose enough to allow manual movement). And if you have a declination motor, you can now make fine adjustments with the motors. Another interesting thing is that Star Hopping is actually EASIER with a GEM mount, even if the mount isn’t perfectly aligned. That is because many Star Hopping instructions say something like “Move your scope south two degrees, then west one degree to find the great Giraffe Nebula.” Well unless you are viewing along the meridian, when doing this with a Dob, moving even APPROXIMATLY South might be a problem because you have to move the mount in two different axis’s at the same time, but with a GEM mount that is even coarsely aligned, if you clamp the RA axis and when you move the OTA South, you can be assured that it is in fact moving pretty-much due South. See, We don’t NEED no stinking Setting Circles Either… So, don’t let a GEM mount intimidate you. And as your experience grows and you ARE ready to start hunting really challenging objects, you can start to learn to do more accurate polar alignment so you CAN exploit the setting circles. Don’t forget that people actually DID use manual setting circles for a couple hundred years with great success. My message here is that GEM mounts don’t MAKE you do complicated things to get basic tracking, but they still allow the OPTION of getting more advanced. If you like to keep it simple, to me, setting up and using a basic GEM mount is actually no more complicated than using a basic Alt-Az mount, and in many ways, a much better proposition, because not only do you get tracking, but you also get geared slow motion controls and true North-South/East-West manual slewing for star hopping.

But if you can afford Go-To, my advice is to get it…. Most of these mounts offer the ability to do the same “Drop it and go” operation with tracking like a basic GEM, but you have far better control over the slow motion speeds and such, and you eliminate problems with balance and eyepiece changes that plague many Alt-Az mounts. Again, you only have to face the mount north and plug it and usually select a “Tracking only” menu choice in to get tracking and electronic slow motion. Again, even a rough alignment will provide good long term tracking.

Here is what I want to leave you with. The C8s ABSOLUTE performance helps it rank as a true bargain in the astronomy hardware universe. A modern one with XLT coatings will give you the deep sky performance of a similar sized Newtonian and the planetary performance very close to a 5” APO, all in a package that is uncannily small and light. It will do this at twice the price of the Dob, but in a much smaller package with superior optics, and in at a price that is a tiny fraction of a 5” APO with premium optics.

Years of charts that say SCTs are simply “Good all around scopes” seem to bias people against the SCT. These charts were an attempt to simplify telescope selection, but in my opinion were VERY badly flawed, because they often made is sound like smaller scopes might do better at something than SCTs, which I find to be generally incorrect. If you are contemplating the purchase of a C8 (or Meade 8” SCT), don’t let those charts that suggest that these telescopes are less than excellent dissuade you. The fact is, the C8 is a tough scope to beat unless you are willing to go bigger, or are willing to spend FAR more money. Relative to cost, the C8 is indeed a SUPERB performer, and in my opinion, is THE scope to beat in the 8” and under category.

I love my C8. If I sell it, it will only be to get a newer one. But I am in good company. Even the owner of one of the most prestigious telescope companies in the world owns a C8…

Regards, and go find some galaxies…


Click here for more about this subject. -Ed.