Starting Out
If your interest in amateur astronomy is truly new, I may have caught you at a time before you really know what this hobby holds. I am going to assume that you do not currently own a telescope or binoculars. If you do, then rush on over to:
Binoculars
or
The New Scope Owner
Both of these pages are equally suited for starting you on the right path, using equipment that you already own.
If you are reading on, then you are a "newbie". So let's get started!
The Magic of Astronomy
For thousands of years, mankind has peered into the vast night sky, and contemplated the nature and meaning of the stars blinking back at them. Without the telescopes and knowledge provided to us by modern day science, ancient people were left largely to their imaginations as they speculated on the nature of the canopy overhead. But the night sky served practical purposes as well. The parade of familiar stars across the sky marked the coming and going of seasons and the cyclical, endless march of time. And without stars, ancient travelers might have been at a complete loss to successfully navigate.
I imagine that our ancestors from hundreds and even thousands of years ago were more aware of the night sky than the average person of today. As we approach the 21st Century, the sight of the universe around us is something that all too many people do not take time in their lives to appreciate. With modern technology, the average person has lost most of the practical reasons for looking up. Fewer still are the people who go beyond the aesthetic views provided by the naked eye and take advantage of the marvelous modern technology that allows us to explore the night sky in ways unimagined by our ancestors. Today's amateur astronomer can surpass many of the achievements of professional astronomers just a few generations removed. The universe is an amazing place, but it is also amazing that we have discovered the technology to bring it all down to earth.
There are many lessons to be learned as one pursues amateur astronomy. Some of those lessons will be on a very human level, as one interacts with other astronomers traveling the same celestial road. You may learn a great deal about the technology you are utilizing to capture the night sky. The workings of telescopes, cameras, film, and CCD chips may become common knowledge to you. You will learn your way around the celestial sphere, just as your ancestors did. And you will learn much more about the pure science of astronomy and come to understand the nature of many objects in the universe.
As one explores the universe, starting with some of our closest celestial neighbors, like the Moon, and advancing out beyond the edge of our own galaxy, the Milky Way, there is a realization that Earth is but the smallest piece of the galactic puzzle. Gaining a new perspective on life is perhaps one of the greatest rewards of becoming an amateur astronomer. The new perspective does not come all at once. It comes over time, as you soak in more and more of your celestial surroundings.
Think of the wonders that there are to see: Our moon, only some 250,000 miles away in space, conducts a perpetual dance about our planet. Our neighbor still has mysteries to reveal regarding its origin. Even a modest telescope allows one to explore the surface of this magnificent world, learning valuable lessons about lunar geology. Within the airless, waterless, and windless confines of the moon, we have the opportunity to see a part of our solar system almost frozen in time. Only the cosmic rain of the solar wind and the pelting of micrometeorites etches away at the lunar surface, on a scale too small to be seen from our perch on Earth.
As we stare farther out across our our own solar system, we find that the stellar wanderers of the night sky, the planets, are anything but pinpoints of light. Our telescopes reveal them truly as other worlds joining us in our seemingly endless dance around the sun. We are able to see dust storms on Mars and the growing and receeding polar caps that might have once provided the water that carved out rivers and canyons mighter than any on Earth. We see the swirling cloud tops of the mighty planet Jupiter, largest in our solar system. When we observe the Great Red Spot in the planet's southern hemisphere, we see an area that can easily swallow Earth, and it gives us perspective on the size of this great gaseous giant. Beckoning at almost twice the distance, we see the mighty ringed planet. And while we can not see the abundance of detail that is to be seen in its "big brother" Jupiter, we readily accept in place of that the amazing ring system that defines Saturn. There is no sight like it available to us in the universe, and it is one that compells each of us to continue our search through the heavens.
As we push our way out of the solar system, deep into the spiral arms of the Milky Way galaxy, we always make one of our first telescopic stops in the sword of the great constellation Orion. Looking into the heart of the Orion Nebula and seeing a young cluster of stars emerging from the sheath of hydrogen which had encapsulated them is like looking back in time towards the genesis of our own star. It is not difficult to imagine other planets, perhaps like ours, coalescing from the same star
stuff swirling around these newly ignited solar furnaces.
Under a dark, moonless night, you scan the skies overhead with the naked eye and see an elongated, oval patch of wispy gray standing out in an otherwise dull area of sky. Turning your telescope towards this target, you discover the light that has been streaking towards you has been cast off by the millions of suns that make up the Andromeda Galaxy. With the naked eye alone, you have grasped photons of light which have traveled for some two million years through space. One of the nearest galaxies in our celestial neighborhood, it in many ways mirrors our own galaxy and provides an idea of what our home might look like if we were to ever find ourselves
on the outside looking in.
These are but a minute fraction of the wonders that the universe has in store for you, if only you take the time to look and equip yourself for the task.
Let's move forward and get you ready for the journey!
The First Steps
One of the reasons that you might have turned to this page is that you are eager to purchase a telescope in order to start exploring all of the wonders I have described above. Please wait!! One of the very biggest mistakes newcomers to the hobby make is to rush out and by a telescope before they have done their homework. This can lead to a very disappointing experience, since many beginner scopes will fall short of meeting many a newcomer's expectations.
Here is what I suggest you do:
1. Check out a beginner's astronomy book from your local library.
There are many titles on the market that will introduce you to the basics of the hobby. In fact, visiting my Binoculars and The New Scope Owner pages will do the job as well. Doing some up front reading will help prepare you for the journey ahead. One of my favorite books, and one that will serve you well as you start out, is "The Universe Next Door" by Terry Holt (Scribners). Some things you need to learn:
Basic functions of a telescope, including light grasp (most important), resolution, and magnification (least important).
Telescope designs. I've included some information about this on my page written for Youth . When the time comes to shop for that new scope, you will be confronted with many choices and features. The most basic things to understand are the differences between optical systems (e.g., Refractor, Reflector, and Catadioptic) and mounts (e.g., Alti-Azimuth and Equatorial, and their variation). If you gain an early grasp of these designs, it will make your subsequent shopping research much easier.
Learning what constitutes "Deep Sky" objects. Unless you end up concentrating primarily on objects within our own solar system, Deep Sky objects are what you will most often pursue. It is very important that you develop a realistic expectation of what these objects will look like through a telescope, versus what they look like in a photograph. In short, planets and the moon can look better through a scope than most photographs (though CCD technology is challenging that premise). Film, however, cannot capture details and contrast as well as the human eye. Deep Sky objects, however, are ideally suited for film and CCD chips. Cameras can do what the human eye cannot ... accumulate light via a time exposure, thus making faint objects brighter and brighter. With the dark adapted human eye, you can only capture the image as it appears at single moment in time. Don't take that as a negative (no pun intended)..... the visual pursuit and study of deep sky objects is a vastly rewarding aspect of this hobby. In fact, it is the primary interest of most serious amateur astronomers.
Learning about the objects that make up our own Solar System. You probably know the names of the planets already, and have an idea of what comets and asteriods are. Get to know a bit more about the nature of these objects via books. It will help you understand what you are seeing when that new telescope is pointed at them for the first time.
2. Get to know your way around the night sky.
Assuming that a computer controlled telescope is not in your immediate future, if you are going to find anything other than the Moon and the brightest planets, you need to know at least some of the major constellations and brighter stars in the sky. These will provide landmarks for you as you scour the sky in search of objects that are only visible in your binoculars or telescope. Eventually, you will want to purchase a set a planisphere and/ore a set of star charts (see below). In the meantime, start out by picking up a copy of either Sky & Telescope magazine http://www.skypub.com/s_t/s_t.shtml or Astronomy magazine http://www.kalmbach.com/astro/astronomy.html. Both are published monthly, and contain a basic star chart that will help you accomplish the task of identifying the most prominent constellations and stars. I can't emphasize enough how important it is that you get started on this project!
![[IMAGE]](planisph.jpg)
Planisphere
To use a planisphere, you rotate the dial so that the part of the sky visible during the date and time you are observing appears in the open window. Planispheres feature all of the constellations and brighter stars .... ideal for your first project! I still use mine, even after many years in the hobby.
![[IMAGE]](chart.jpg)
Star Chart
A star chart is a more detailed map of a smaller section of the sky. The chart page shown above is from Wil Tirion's Sky Atlas 2000 (one of the most popular star charts). The Telescope & Bincular Center has a selection of star charts for sale.
3. Attend at least one or two meetings of a local Astronomy Club.
Almost every metropolitan area has at least one amateur astronomy club. Even if you ultimately decide that astronomy is a pursuit best done in solitude, I think you will agree in the end that getting some exposure to other amateurs as you start out in the hobby is of great value.
Most clubs focus their efforts in three areas:
1. Sharing knowledge during meetings, typically through presentations by members and/or guest speakers.
2. Observing nights. These are planned outings to safe and secure observing locations. Sessions are sometimes only available to club members. Other sessions may also be open to the general public.
3. Public education. Club members volunteer there time to do presentations for schools, or take their telescopes to areas where the general public can share the observing experience.
Check out this AOL link for a list of Local Astronomy Clubs.
4. Read some of my other pages. Especially:
The New Scope Owner
Binoculars
Youth
Even though the titles might not seem to apply to your situation, trust me when I tell you that you will pick up valuable information that will help you as you start out in the hobby.
So ..... you've done your homework and taken all of the suggestions listed above. I can hear you screaming all the way down here in Jacksonville .....
Hey Don!!!! All of that is great, but cut to the chase ........ what kind of telescope should I get?!!!
Ok, Ok. Here is my best advice:
There is no such thing as one perfect telescope for all amateur astronomers. Every amateur has unique observing or imaging interests and unique observing conditions that they have to deal with. With that in mind, your key mission in life when searching for your first telescope is to choose the telescope that is right for you. Here are the key things to consider that will help you choose the best, first scope.
1. Lifestyle ..... the biggest factor
I would argue that your lifestyle is the single biggest factor in deciding upon the right telescope. For example: if you live in a third floor apartment with no elevator, own a sub compact car, and have a work and family schedule that permits you to only observe for very short periods of time ( e.g., 30 mintues or less), then your list of potential telescopes is best confined to small, portable instruments. If, on the other hand, you live in a rural setting under dark, pristine skies, and have the land, money, and time to build a permanent observatory for you and your telescope, your choice of first scopes will be completely different.
It is critical that you be honest with yourself about the limitations or opportunities that your lifestyle imposes upon your new hobby, and ensure that you select a telescope that compliments your situation.
2. Budget
Let's face it.... money, or the lack thereof, will be a major factor. Be it big or small, the vast majority of us have to work within a budget when setting ourselves up in this hobby. As you create your budget, it is important to keep in mind that it takes more than just a telescope to get started. There will be a number of other accessories that are required for a complete and successful telescopic tour of the night sky. Fox's rule of first telescope shopping says:
Set aside 25% of your budget for accessories!
For example, if you have $400 to spend, plan on $300 going to towards the scope, and $100 towards accessories. This ratio will hold pretty true for first telescopes up to a price of about $2,000. After that, the % for accessories starts to go down a bit.
Sure, you can proceed without setting the money aside for accessories up front. But if you spend all of your money on the basic scope, you will soon find yourself in the following situations:
A) The scope came with only one eyepiece, providing one magnification. You realize right away that you need variation in magnification. This means more eyepieces, which cost more money. In fact, your eyepiece collection is eventually where the biggest chunk of your accessory money will go. Over the long haul, you might even spend more money on eyepieces than you originally spent on the telescope!
![[IMAGE]](eyepiece.jpg)
Eventually, your investment in eyepieces may exceed the cost of your telescope! At today's prices, the above sample of eyepieces and filters would run about $2,000.
B) On your first humid night of observing, you discover the astronomer's worst enemy: DEW! Some money might have to be spent on dew fighting accessories that will help you enjoy your observing time unhindered.
![[IMAGE]](dew.jpg)
A DC powered anti-dew device. Bascially, a heating strip that helps keep the temperature of the exposed optics just slightly above that of the dew point . In some parts of the country (those with routinely high humidity), dew protection is an absolute must. A "dew cap", which attached to the end of the tube, can hold off dew for a little while. But for long observing runs, you need to elevate the temperature of the optics.
C) If you have a desire to view the sun, a safe solar filter is a requirement.
D) If your interest is in observing "Deep Sky" objects, star charts and possibly a planisphere are a must. You need some way to find your way around the sky!
E) Heck.... forget about finding your way around the night sky! You need to find a way to see the work area around your telescope first! If you are into observing deep sky objects, then you need to protect your night vision. That means using a flashlight that only casts a red light.
F) Got a clock drive on that scope? Then you will need a way to power it. If it doesn't run on internal batteries, or you can't run AC power to it via an extension cord, then you might be looking to shell out a few bucks for a portable, rechargeable battery. Or at the very least, you will be buying DC extension cords to run it from your car's DC cigarette lighter outlet.
G) Depending on the eyepiece height of your scope, and the length of time you usually spend observing, you may need a chair. A regular old chair might do, but if you observe frequently for long periods, then you will find an adjustable observing chair to be invaluable.
![[IMAGE]](chair.jpg)
An adjustable observing chair. This particular model gets rave reviews among amateur astronomers. It is very comfortable, offers solid back support, and most importantly, can be quickly adjusted to a wide range of observing heights without using a single tool.
3. Portability
This sort of fits in the "lifestyle" category, but it really deserves it's own place on the list.
A common saying among amateur astronomers is that "the best scope is the one that gets used". A $5,000 telescope is not of much value to the owner if its bulk makes it a hassle to set up for viewing, and as a result, the owner loses the desire to get out under the night sky.
When I say "portability", I am speaking on two different levels. If you plan on doing all or most of your observing at home, then portability means being able to move the telescope from its daytime storage area to your night time observing spot. If taking the scope outside is an inherent hassle, your enthusiasm for astronomy might fade. This is particularly true, in my opinion, if you lose the ability to go outside on a whim. Given today's hectic lifestyles, one must be able to seize observing opportunities when they present themselves. So having a telescope that can be carried outside in one or two trips, and involve minimum set up time, can be very desirable. The size of the scope which meets that requirement will depend on your individual size and strength, and the obstacles (such as stairs and doorways) that you might have to navigate to get the scope out under the stars.
Of course, you can make bigger telescopes more manageable by housing them in a permanent location outdoors. Building an observatory is an expensive proposition, however, and something that is typically pursued by more serious amateurs who have been in the hobby for a while.
Another alternative is to make your scope more mobile by adding wheels or a platform to it. That's what I have done with my scope (a Celestron CG-11, which weighs in at more than 100 pounds, not including accessories). I simply wheel it out of the garage into my drive way for observing. My power supply and all of my accessories are kept underneath the scope. I am set up and ready to go within a matter of a minute or two. This platform, which I made myself, probably increased my observing time at least twenty fold.
The other aspect of portability is the ability to break the scope down for transport in your vehicle. This will be very important if you plan on observing from a remote, dark sky site away from your home. Again, it is important to avoid the "hassle factor". If loading up, set up at the site, and tear down become too big of a chore, you might find yourself passing up observing opportunities.
It is also a basic, fundamental aspect of research, before you buy the scope, to ensure that the largest pieces (such as the optical tube assembly) fit in your car or trunk!
4. Your observing interests
This is really the most important consideration of all. You must balance what it is you wish to observe versus all of the other considerations .... lifestyle, budget, and portability.
There are several key areas of interest for the astronomer pursuing the heavens with a telescope. You might find that only one of these areas interests you. Or perhaps all of them appeal to you. Perhaps you will settle on a couple of them as the key areas in which you will develop greater expertise:
1) Solar observing
2) Planetary observing, perhaps with specialization on certain planets (only Venus Mars, Jupiter, and Saturn lend themselves to being targets for study in amateur scopes. Sure, you can see all of the planets in most scopes (Pluto being the biggest challenge, and out of reach for small apertures)
3) Lunar observing
4) Double & Multiple Stars
5) Variable Stars
6) Deep sky objects, perhaps with specialization on one or more of the subsets of deep sky objects, such as:
Galaxies
Nebula
Planetary Nebula
Open Star Clusters
Globular Star Clusters
Picking the right scope
So how do the various telescope designs and models satisfy all of these requirements? Let's explore some of the strengths and weaknesses of the various commercial scopes available on the market, focusing in on how they fit the four key criteria I have mentioned above.
1. Small Scopes .... meeting the needs of convenience, portability, and budget
If you are pressed for time and can only enjoy short trips under the stars, your first choice might not even be a telescope! Binoculars might do the job just fine. You can get a quality pair of binoculars starting at around $150 dollars. 7 X 50's are most often recommended for astronomy. Personally, I would lean towards 9 X 63's. Celestron and Telescope & Bincular Center both offer 9 X 63's, priced at about $350 and $250, respectively. The extra aperture is beneficial, and the weight of the binoculars is still manageable for holding by hand. Once you get up to the 70mm and 80mm binoculars, using a tripod becomes a necessity. If binoculars are of interest to you, I also recommend that you visit my Binoculars web page.
If a scope is where your interest lies (and a scope is a must if you have an interest in observing the planets or examining deep sky objects at greater magnifications than binoculars can provide), there are several choices that are very portable. They also fall across a wide range of budgets:
A) 70 or 80mm short focal length refractors
Prices range from $250 to over $1000 for the optical tube alone. Mounts for these scopes are usually sold seperately. A good mount will run you at least $200, and purchasing a high quality mount in the $500 to $800 range is not out of the question.
These scopes are very good performers for wide field views of our own galaxy. Many of them also make excellent camera lenses for astrophotography. They also serve extremely well as daytime spotting scopes. If there is a drawback to these scopes, in my opinion, it is that the short focal lengths make it difficult to use higher magnifications for lunar and planetary observing. I have owned an 80mm Celestron f5 (400mm) refractor for several years. It is a great daytime spotting scope, a very solid performer for piggyback astrophotography, and provides good wide field views of the night sky. I find it very lacking for planetary observing however, and would never consider it as my only telescope if I were starting out. My shortest focal length eyepiece (4.7mm) yields only 85X with this scope... too little for satisfactory planetary observation. To achieve a more desirable magnification in the 150X range (for planetary observing), it would take a barlow lens with a short focal length eyepiece.... in my opinion, too much glass to stick on this little engine.
If you think that this type of scope meets your needs, you'll find models from Orion and Celestron in the $250 to $300 price range (without the mount), and premium models from Tele Vue (their Ranger and Pronto) in the $650 to $1050 range (again, without the mount).
B) Smaller Catadioptrics (5" or less of Aperture).
Prices range from about $600 for a Meade 3.5 ETX (Maksutov design) to a 3.5" Questar for over $3,000. In the middle is a Celestron C5 (Schmidt Cassegrain) for about $1,100.
The Maksutov design was popularized by Questar many years ago. Questars are finally crafted instruments, and their reputation is well known within the amateur astronomer community. They have a very long focal length of about 1300 mm, which makes them much better suited for planetary and lunar observing than the short tube refractors noted previously. In spite of all that, I have a very difficult time recommending a $3,000 scope of this size to someone as their first instrument. The only way I would is if you were to tell me that for many years to come, your sole interest would be to have a high quality ultra portable travel scope. Or perhaps you have some physical limitations that prevent you from lifting or carrying a scope of any significant size. If this described your lifestyle conditions, and money was no object, I would recommend a Questar.
At the complete opposite end of the financial spectrum, Meade offers a 3.5" Maksutov (the ETX) for $595. They apparantly have sold a huge number of these scopes since they introduced them a year or two ago. In fact, there was quite a run on them early on, making them difficult to find. The price, compared to a Questar of the same aperture, certainly makes them attractive for someone looking for an ultra portable scope. I have heard very mixed reviews on the ETX, however. The finder is apparantly a waste and postioned on the tube so that you cannot use it very well. There is a lot of plastic in the construction, and perhaps most important of all, the scope cannot be pointed down to the southern horizon when set up in the equatorial mode and polar aligned. The further south you live, the bigger the problem this presents, as increasingly larger chunks of the southern sky get removed from your view.
3.5 inches is 3.5 inches, and with aperture being a key factor in telescope performance, coupled with the drawbacks of the ETX design, I recommend the Celestron C5 Schmidt Cassegrain as the portable Catadioptric of choice. The table top version of this scope is very portable indeed. The 1.5" of extra aperture over the ETX and Questar is substantial in terms of light gathering and resolution, and the focal length is almost equivalent at 1250mm. The clock drive operates on a 9 volt battery. The 6X30mm finder is far superior to the one supplied on the ETX. And there is no problem with swinging the optical tube through the fork mount, thus ensuring access to the entire sky. In short, I believe the C5 offers the best combination of price (about $1,200) and performance in a catadioptric design.
C) The Edmund Astroscan
One cannot mention portability without mentioning the Astroscan by Edmund Scientific. This is a 4" f 4.2 reflector, with a unique design that allows the scope to actually be used cradled in your lap. The optics don't lend themselves well to higher magnification planetary or lunar viewing, however. It is really a wide field instrument in the truest sense. The price is about $350. Many amateurs either love or hate these little scopes. I don't recommend them. I believe there are more versatile scopes in the same price range.
D) Small Newtonians (4.5" or less)
Most 3" or 4.5" Newtonians might be considered to be "grab and go" scopes by some, so I have included them here. There are a wide range of manufacturers ... too many to list, frankly . Prices range from as little as $100 to over $600.
Personally, I would stay away from a 3" Newtonian. In the same price range, a 60mm refractor will provide you with close to the same level of performance, but without any of the hassles of collimation, cleaning, and maintenance that a Newtonian demands.
In the 4.5" class, there is little doubt in my mind as to my recommendation: the Celestron C4.5 comes equipped on the best mount of just about any scope in this class. While more expensive than the competition (the C4.5 runs about $600), the mount, which is manufactured by a reputable Japanese company named Vixen, makes it worth the price. The 900mm focal length is suited for planetary and lunar observing, especially when coupled with the fine mount.
Both Meade and Orion offer 4.5" Equatorial Newtonians for about $200 less than the C4.5. If your budget doesn't have room for the C4.5, you certainly can consider either of these instruments. The optical quality should be about equal.
A final word on portability of these Newtonians: they may not qualify as "grab and go" for everyone. The C4.5 weighs in at 28 pounds, the Meade 4500 27 pounds.
E) 60 to 90mm Refractors
"Full size" refractors in this aperture range might also qualify as "grab and go" scopes. If a refractor is really what interests you, stay away from the 60mm refractor lines, budget permitting. An 80mm or 90mm refractor, on the other hand, can prove to be a worthwhile investment for a portable scope that is easy to maintain and use.
I personally recommend that you consider an alti-azimuth mount for refractors of this size, especially if this will be your first scope. An equatorial mount may look very high tech and appealing, but the truth is that many of the entry level equatorial mounts are not well crafted enough to make the setting circles a real assett. An equatorial mount is also very valuable if you want to use a clock drive for tracking objects at high magnification .... but honestly, the maximum magnifications you would use with these scopes (about 150X to 175X) can be handled quite handily on an alti-azimuth mount. I think it provides better value for your dollar as well.
Prices for 80mm refractors start at about $300, and run up to about $600. Prices for 90mm refractors begin a bit higher (about $500) and end a bit higher ($2000 for a Vixen 90mm Flourite Refractor). A good quality refractor in the 80mm to 90mm range can be an excellent starter scope. They require very little maintenance, and will give you their best images right out of the box.
2. Larger Aperture Portable Scopes
The next step up in scope size and ease of use/portability takes us to a variety of instruments in the 4 to 13 inch range. These scopes, while of ample aperture, can still be quite portable.
The Schmidt-Cassegrain
Inch for inch of aperture, the degree of portability all depends on the design of the optical system and mount. The most famous telescope design, in terms of facilitating portability, is the 8" Schmidt-Cassegrain Telescope (SCT). Eight inch SCTs weigh in at as little as 37 pounds. There are a number of 8" models on the market, with a variety of features. There are two primary manufacturers: Celestron and http://www.meade.com/ . Prices start at about $1100 (Celestron Celestar 8"), and top out at $2800 for a Meade 8" LX200 computerized scope.
One very important consideration to keep in mind, should you be shopping for an 8" SCT: Both Meade and Celestron use the exact same optics on all their respective 8" models. So whether you spend the $1100 or $2800, you will enjoy the same optical quality and view.
Given that the optics of each brand name are equal within their respective lines, your purchasing decision on 8" SCT's will boil down to a combination of price versus the non-optical features of the scope. Of these features, the type of mount being sought is usually the determining factor for the buyer. Today's 8" SCT's basically come on one of three types of mounts:
Equatorial Fork Mount
Alt-Azimuth Fork (all with computer control)
German Equatorial Mount (GEM)
The equatorial fork mount had been the standard for SCTs for many years. Within the last three years, however, the popularity of the Meade alti-azimuth computer controlled scopes (the LX200 series) has surged, and Celestron has followed suit with their version, the Ultima 2000. The single biggest drawback to the alti-azimuth fork is that it limits the scope's ability for astrophotography (due to field rotation that occurs in a scope that is functioning in alt-az mode). This forces the owner who becomes interested in astrophotography to either puchase an optional equatorial wedge , or buy a device known as a field derotator. It is important to note that the field derotator only corrects for photographs taken at the prime focus of the telescope. If you ever want to use the telescope as a platform for "piggyback" photography, you will need to go the route of adding the equatorial wedge (or simply buying an equatorial fork version to begin with).
Of course, the advantage (and the resulting premium price) for the alt-az SCTs is the "GO TO" computer capability of the scopes. Punch in the information for any object in the on-board computer's data base, and away you go. Meade and Celestron's computerized scopes have been out on the market long enough to allow the manufacturers to apparantly work out the early design bugs. When computerized scopes first appeared, you wouldn't believe the debates that raged within amateur circles about the merits of such scopes. Without the computer, of course, you have to find faint objects via other means: Using the "star hop" techinque in conjunction with star charts, for example. Or perhaps using the RA and Declination setting circles provided on equatorial mounts (which, after all, is just a mechanical means of accomplishing the same thing as the computer). The debate about the merits of GO TO scopes seems to have waned over the past year or two, however. Personally, I have never owned a computerized scope. But I wouldn't have anything against owning one (especially if I were were heavy duty into CCD imaging, and wanted to be able to drop small and faint objects right into the limited imaging area of a CCD chip). All of the high tech coputerized features come at a price, obviously. In both the Meade and Celestron line, you pay about $1000 more for a computerized scope than their top of the line 8" equatorial fork version.
The German Equatorial Mount (GEM) seems to be enjoying a bit of a comeback as a mount for SCT's. Celestron has maintained a GEM 8" model for years. Currently called the GP-C8, it sells for about $1,400. Keep in mind, however, that it does not come equiped with a clock drive, which is, at the very least, required for astrophotography. If you want to truly use the scope to its full visual potential, especially for higher magnification lunar and planetary viewing, a clock drive is really a must. Plan on spending at least another $200 to $350 for a single or dual axis drive. Meade has jumped into the 8" GEM SCT offering now and then over the years. They are back in the hunt once again with the model 203SC/500, priced at about $100 less than the GP-C8 (you need to add a clock drive system to this one, too).
Personally, I prefer a German Equatorial Mount (GEM). I believe that they are more versatile, especially when it comes to balancing the scope after adding heavy accessories, such as 2" eyepieces or camera equipment. The nature of a GEM also ensures that all areas of the sky are viewed with relative ease; you run into a bit of difficulty with an equatorial fork mount when pointing it in the within 10 degrees or so of the North Celestial Pole.
Having said all of that, the Celestar is, in my opinion, the best buy at the low end of the price scale. While it uses a lower cost mount to achieve some of the cost savings, it's primary merit rests in the fact that it comes standard with some important features: a tripod and a battery powered clock drive. By comparison, Meade's lowest cost 8" SC is priced without a tripod, and both Meade and Celestron's German Equatorial mounted versions come without clock drives. The biggest trade-off on the Celestar is that the tripod is of a fixed height, coupled with the fact that, of all the 8" SCTs, it is probably least suited for prime focus deep sky astrophotography, due to some of the mount considerations.
To this point, I have only focused on 8" SCTs. But there are a numebr of larger models available on the market from both Meade and Celestron. If you start to explore these as options, keep in mind that, while certainly more portable than other scope designs of equivalent aperture and focal length, they start to get rather bulky.
For starters, Celestron offers equatorial fork mounted 9.25" and 11" SCTs (The Ultima). The 9.25" version features an enhancement to the optical tube called a "focusing micrometer", which basically allows you to remember where the best focus setting was for a given eyepiece or, more importantly, for a camera. These instruments weigh in at 74 and 80 pounds, respectively, so you can see that they are sizeable instruments. Prices run about $2,450 and $3,100.
Celestron also offers both of these optical tubes in a GEM version. In this case, however, the clock drive and hand controllers are included in the price of scope. The CG-9 is priced just slightly higher (about $100) than the Ultima 9. The CG-11 is priced some $700 more than the Ultima 11, however. The difference rests in the GEM.... the CG-9 uses a different equatorial head and tripod than the CG-11. From reports I have read, the CG-9's aluminum tripod might not be beefy enough for the 9.25" optical tube (the equatorial head itself appears to be fine). The total G-11 mount, on the other hand, is more than adequate for the 11" optical tube. In fact, this same G-11 mount is used for Celestron's 14" SCT optical tube (at a price of almost $6,000), so it can handle the 11" quite easily. On the basis of what I have heard about the respective mounts, I would recommend the Ultima 9.25 over the CG-9 version (despite my liking GEMs), and the CG-11 over the Ultima 11 (assuming that both are within the buyer's budget).
Meade also offers larger aperture scopes, of course, and they should not be overlooked by the prospective SCT owner. Only the 10" version is offered on an equatorial fork mount (the LX 50). At about $2,000, it is a great value for a larger aperture SCT (especially when comparing it to either version of Celestron's 11"). The 10" LX200 (computerized) version is also a good buy at $3,200, especially when you consider that the Ultima 11 is priced about the same.... without a computer GO TO system.
Some of the value in the Meade SCT line starts to dry up when you get to the 12" LX200, however. At $4,500 , you have to look real hard at the value of the computer system and the extra inch of aperture compared to either the Ultima 11" or the CG-11. And whereas the CG-11 is farily portable, due to the manner in which it is constructed, safely assemblying the Meade 12" is as close to a two man job as you can get. And finally, at the upper end of commercial SCT's, you have the monster Meade 16", priced at a whopping $15,800. This scope certainly has some features that the Celestron CG-14 does not, but it is hard for me to imagine anyone spending $10,000 more for a SCT scope with only 2" more aperture. But go figure ..... they are selling them.
Are there other reasons to consider SCT's besides portability? There sure are. First of all, they are more convenient for astrophotography than just about any other scope out on the market. There are also more readily compatible accessories for SCTs than any other type of scope. And finally, they sit in the middle of the pack when it comes to cleaning and maintenance..... easier to care for than Newtonians, but short of the ease of ownership that a refractor provides.
But what about the optics for visual use? In amateur circles, that's where the biggest debate about SCTs seems to rage, in large part due to the larger central obstruction of the scope (compared to most Newtonians), which results in a loss of contrast. I have owned SCTs for over almost 12 years now ... first a C8, and most recently a CG-11. When collimation of the scope is maintained properly, my scopes performed extremely well in terms of resolution and image brightness for their aperture. The most notable weakness compared to other types of scopes I have sampled is that, in the SCT, the background sky surrounding bright planetary images shows scattered light, which is created by the SCT secondary. I have also noted on occasion, versus some scopes, that the background sky can appear slightly lighter (all related to the contrast situation).
How big a negative is this? I think it depends on what is important to you in your observing program. My primary observing interest these days is lunar and planetary observing, and the 2800mm focal length I gain with a CG-11 is simply invaluable to me. With the scope functioning at its theoretical limit of resolution under excellent seeing conditions, 11" of aperture provides a potent planetary punch. When I compare observation notes with other skilled observers around the country using a variety of instruments, I have never gotten the feeling that I am missing anything in my observations that is being reported by others via other instruments. So for me, selecting a SCT has allowed me to put the largest possible aperture to work in a convenient fashion.
It is a given that a refractor of equal aperture is going to significantly outperform an SCT. But 8" refractors are rather cost prohibitive (as you will see later in this piece), and I have never met anyone in the position of choosing between an SCT and a Refractor of equal aperture. Certainly, a well corrected APO refractor is a highly desirable instrument. But one must always keep in mind the importance of aperture in any observing program. I am not sure at exactly what aperture an APO refractor becomes more desirable than an 8" SCT, but I suspect that it is at 5 inches. I think at least a 6" APO would be needed to outperform a 10" or 11" SCT at their best for planetary observation. Deep Sky observation is another matter alltogether, where aperture takes on even more significance.
The bottom line is that I advise people not to underestimate the optical quality of SCTs. Certainly, some of the best amateur astrophotography is produced with them, and very serious observation programs are pursued.
Other Catadioptrics
There are other portable "CATS" on the market besides the ones I've described by the two largest manufacturers. Some are lower cost alternatives, while others demand premium prices.
The Maksutov design, popularized by Questar, is currently in use by several manufacturers. Questar themselves offers a larger 7" version of their 3.5" scope, but the cost is way up there. You can check out current pricing for this scope (and many of the others I've mentioned) at Company Seven Astro-Optics Division Home Page . I have not yet ordered anything from this company, but their reputation precedes them. They inspect all of their scopes before the sale, have competitive prices, and are reported to have excellent service.
Telescope & Bincular Center , a.k.a. Orion, currently offers some other CATS as well. Their 6" Argonaut Maksutov-Cassegrain looks like it has the potential to be a good performer. The optical tube sells for $1,000 (you have to purchase a mount seperately). Orion has also just introduced an 8" Cassegrain, which uses a different approach to introducing portability than does a SCT. Instead of a corrector plate at the front of the optical tube, they use a field corrector near the eyepiece end of the scope. I have not seen one of these scopes yet in person. I am very interested in seeing how the image quality stacks up.
Meade also offers a 7" Maksutov. The equatorial fork version sells for about $2,250, while the computerized LX200 version sells for slightly over $3400. I haven't heard too many reports on this scope. Given the f/15 design, I would think that it would be a good lunar/planetary performer.
Equatorial Newtonians
Equatorial mounted Newtonians dominated amateur astronomy during the sixties and seventies.
The catch with larger aperture Newtonians is that they quickly outgrow the semi-portable classification. Due to the length and overall weight of a typical large aperture Newtonian, it takes quite a massive GEM to deliver a steady image. If you want to conduct successful astrophotography with such a scope, you are really talking about a monster. As a result, most GEM Newtonians above 10" in aperture are, more often than not, relegated to owners who use them almost exclusively at home, or have them housed in a permanent observatory. Six and 8 inch GEM Newtonians can be transported with relative ease, however, if the focal length (and thus the tube length) is short enough to allow for transport in your vehicle. Ten inch GEM Newts are about the highest you can go and still have a reasonably portable instrument.
The largest manufacturer of GEM Newtonians is surely Meade. Their Starfinder Equatorial line constitutes the most prominent line of GEM Newts on the market. These scopes are attractively priced, and represent a good value. A 6" f/8 starts the series at about $720 (including shipping). The 8" f/6 comes in at $825, and the 10" f/4.5 $970. The knock on these scopes, if any, is that the mounts are a bit undersized on the 8" and, especially, the 10". As a result, they are reported to be a little bit limited in their use for long exposure astrophotography.
There are other GEM Newt manufacturers out there, but they stay pretty low profile on the advertising front (but then, compared to Meade, who isn't). Browsing through recent issues of Sky & Telescope and Astronomy, some of the companies I made note of were:
International Optics Limited - 6, 8, 10, & 12" models
Sovietski - 4.5 and 6" models
JMI - 12.5" (not a GEM, but a split ring equatorial)
Starsplitter - 4.5" and 6" models
Orion Telescope & Bincular Center has also started carrying an 8" f/4 Newtonian manufactured by Vixen of Japan. Perhaps the best known GEM Newt alternative to Meade, however, is Parks.
A good source for links to many scope manufacturers and distributors can be found at the Astronomy-Mall.
Dobsonians
Dobsonians are simply alti-azimuth mounted Newtonian telescopes. The namesake of the design, John Dobson, supposedly had low cost and simplicity in mind when he popularized this design. Over the years, however, several classes of Dobsonians have emerged. On top of the low cost and simply designed entries, you now have very expensive, large aperture top of the line models that are nothing short of works of art.
As evidenced by a comparison of the ads in the monthly magazines, "Dobs" dominate the Newtonian ranks. If you are looking to get the most aperture for your money, there is no doubt that a Dob is the way to go. Before considering a Dobsonian, however, it is important to remember that, due to the design of the mount, they are not suited for astrophotography. And while some versions can be found on equatorial style platforms, or equipped with stepper motors that allow them to track in alt-az mode, the models I will be discussing here are more entry level instruments that require all moving and tracking to be done by hand.
Commercial Dobs originated years ago with a company called Coulter Optical. Until the early 90's, they were the only major player in low cost Dobs (most other low cost Dobs were being made at home!). Their "Odyssey" line of Dobs really defined what commercial Dobs were.
But in the 92/93 period, Meade and Orion jumped on the bandwagon. Seeing that Coulter, a relatively small company, couldn't keep up with demand and ensure reasonable lead times for delivery of their scopes, both companies raced to fill the void.
The quick success that both Orion and Meade experienced in the low cost Dob market demonstrated just how much pent up demand there was for this type of scope. A new wave of "aperture fever" swept the amateur astronomy community. Long time users of 8" scopes suddenly realized the opportunity to make a huge jump in light gathering by moving up to 12 inch and larger instruments. The 6 and 8 inch Dobs provided a much more cost effective way to enter the hobby with significant aperture.
Currently, there is a big market share battle under way between the "Big Three" Dobsonian manufacturers: Orion, Meade, and Celestron. Unfortunately, Coulter fell on hard times, and went belly up. Within the past year, they were bought out by another company, MURNAGHAN Instruments CCD, Telescopes, Video Microscopy, Imaging , and are back in business under the Coulter name (they are still undercutting the "big three" on price, inch for inch of aperture).
The "Big Three" companies price their instruments on the lower end of the Dobsonian scale, and the fit and finishes reflect that fact (perhaps with the Celestron instruments being just a tad bit more innovative on design). Some things that they all have in common:
* Sonotube type optical tubes (Celestron offers an aluminum tube version of their 8")
* Laminated particle board construction on the base of the mount.
* Minimal hardware
* Barely adequate altitude and azimuth bearings
Some of my observations on the quality of these instruments are based on my own experience owning a Meade 12.5" Dob, and from reading the reports from other users. It seems that many users who stick with the instruments (especially the larger aperture models) as their primary scope end up making a number of upgrades to improve performance.
It is important to note one other very important point about the "Big Three's" Dobs: all reports I've read regarding the optics have been pretty favorable (as was my experience with the 12.5"). They seem to be doing a good job sourcing mirrors, especially for the price. And after all, this is where the value of the Dob lies in the first place.
A 6" Dobsonian is a terrific first scope for the person on a modest budget. For about $400, you get a good amount of aperture, typically in an f/8 design. The scope is also fairly leightweight and portable. Compared to any other scope in the $400 price range, a 6" Dob will offer the best views of all celestial objects.
As the Dob's aperture increases, the focal ratio tends to get faster, primarily to keep the scope portable and manageable (since you aren't doing any astrophotography, the only other advantage to the short f ratio is the wider field of view that becomes available, compared to a longer focal length scope of equivalent aperture). By the time you get to apertures of 12.5 and 16 inches (or more), you are usually dealing with scopes that are about f/4.5. The lower the f ratio, the more critical collimation becomes. So if you become a large aperture Dob owner, expect to become a master of collimation ... otherwise, the scope will never live up to it's potential (especially for lunar and planetary observing).
8" Dobs run closer to the $500 mark. If you are interested in a Dob, and have the budget, I would greatly encourage you to hold out for an 8" Dob over the 6". In my experience, 8 inches of aperture seems to be the threshold for satisfying deep sky observing. Many deep sky objects begin to reveal more structure and detail than is visible with lesser apertures (even just 2" less). Many Globular Clusters, for example, are resolved much better in an 8". An 8" instrument becomes a bit more sensitive to "seeing" conditions when viewing the planets and moon (a 6" is pretty ideal in that respect). But when seeing is above average, you will enjoy the benefits of the improved resolution that the extra 2" of aperture provides.
Once you move above the 8", you are dealing with instruments that begin to get a bit bulkier, and portability becomes a bigger issue. If you are going to be transporting your instrument to dark sky sites in order to enjoy the full benefit of all that glass, make sure it fits in your vehicle! A 16" is quite a monster!
10" and 11" Dobs run between $600 and $900, depending on how they are equipped (in terms of focusers, finders and the like). 12.5" models are running between $900 and $1,100, and the largest 16" and 17.5" models from the big three are running between $1,200 and $2,000. As competition has heated up among these three manufacturers, they are providing more and more optional configurations for the escope. Make sure that you check the features on each model very carefully, so that you are viewing the prices "apples to apples" across the competing brands' lines.
A few suggestions for outfitting your "Big Three" scope:
* Add the best focuser you can afford. I recommend a rack and pinion, versus a helical type.
* Add a "one power" finder ... it will be of great value for pointing the scope toward an object (sighting down the optical tube can be a bit awkward.... these devices really earn their keep). I think that this is even more important than your "regular" finderscope. If you have a good low power eyepiece that provides a wide field of view, the one mag finder might even be all you ever need.
* You will probably need to purchase or rig up a counter weight balancing system for the tube (especially if you use 2" eyepieces).
* Buy a set of collimation tools at the time you purchase the scope. It will help you get the most out of the scope right away, and save you a great deal of frustration early on.
In addition to the "Big Three" there are a host of other manufacturers at both ends of the price spectrum. Most of the premium Dob manufacturers tened to focus in on larger aperture instruments. They are catering to the very serious amateur who is looking for a well crafted large aperture scope.
It is rare for a "newbie" to start with a scope in this class. Still, if you are interested in hunting them down, some of the companies are:
Starsplitter Scopes
L-5 Systems
JMI
StarMaster Portable Telescopes, Home Page
Refractors - 4 inches and larger
Now we come to some of the crown jewels of the telescope market: larger aperture refactors.
Inch for inch, refractors are the most expensive telescopes on the market. The reason is simple: it takes a lot more effort to figure the multiple surfaces of an objective lens than it does to grind and polish the single surface of a Newtonian mirror. The glass needed to craft the lens is also much more expensive, and must be of virtually free of flaws.
Refractors that are 4 inches and larger typically consist of objective lenses that are made up of two or three elements. The purpose of the multiple lenses is to reduce or eliminate the effect known as chromatic abberation.
Chromatic abberation occurs when the different wavelengths of white light (e.g., the red and blue wavelengths) come to focus at different distances from the lens (it doesn't happen with mirrors). This shows up as an image that shows false color or halos on the fringes (typically seen when observing bright objects, such as the moon, planets or brighter stars).
For years, the best way to manage chromatic abberation in a refractor was to make the focal length very long. With a single element system, a higher focal ratio (usually f15) would help reduce the extent of the abberation. This is one of the reasons that you still see those 60mm f/15 refractors. But 4, 5 or 6 inch refractors with a ratio of f/15 are massively long .... a 6" would be about 100" in length. So other means needed to be found to manage chromatic abberation.
An achromatic lens usually consists of two elements. The elements are figured differently, so that the various wavelengths of light are brought to a better focus. They are not completely cured of chromatic abberation, but the improvement is sufficient to allow for some shorter focal lengths and excellent images.
An apochromatic lens usually consists of three or more elements, and virtually eliminates chromatic abberation. It also allows even shorter focal lengths, thus making large aperture refractors a more convenient option for the amateur. In addition to the triplet design, some lenses are crafted form exotic glasses, which further enhance the quality of the image. With the lower f/ratio, it also turns them into excellent photographic lenses for deep sky objects. There is no doubt that the top of the line models provide the best images possible, inch for inch of aperture.
One of the keys when considering a refractor is that old magic word: aperture. As good and pure as a quality refractor image may be, they do not defy the laws of optics. The brightness and resolution of an image is always a function of the aperture of the scope, and as a result, a refractor may not be up your alley.
If you are into observing deep sky objects, for example, there is no substitute for aperture. A $900 12.5" Dobsonian will outperform a $5,000 six inch refractor any day of the week. When you are tyring to get the brightest view of faint galaxies and nebula, it isn't even a contest.
Where a well corrected refractor really excels is for lunar and planetary viewing. The absence of a central obstruction results in optimum contrast and resolution. And since typical atmospheric seeing conditions often limit the resolution to about that of a 6" scope, a 6" refractor will often outperform larger aperture instruments.
So what is available on the market? It really breaks down into two categories: Four inch refractors and then everything else.
There are several manufacturers of four inch refractors. A key consideration, if you are looking at this size instrument, is to ensure whether you are looking at an achromatic or an apochromat. There is a huge difference in cost (typically, an apo is double the price of an achromat). And a real "buyer beware" when refractor shopping: just because a manufacturer claims a scope is an apo, doesn't mean that it will perform to true apo standards once you get it out of the box.
Meade, Celestron, and Orion all offer 4" Achromatic refractors on German Equatorial Mounts (actually, the Orion and Celestron scopes are made by the same company, Vixen). Prices rnage from $1,000 (the Meade) to $1,400 (the Celestron). Keep in mind that the mounts do not include clock drives on any of these models, so you are looking at some incremental cost to outift them accordingly.
Each of these companies offer a shorter focal length APO version of the same scope. The prices jumo considerably to about $2,500 for the Celestron and Orion. Meade sells two different versions of the 4" APO (the difference being the mount). Prices are about $1,700 and $2,800.
Three other companies offering APO refractors have very lofty credentials for quality (and prices to match): Takahashi, TeleVue, and Astro-Physics.
Takahashi's 4" APO's, with mount, go for between $4000 and $4500 (the high and low represent different mounts). TeleVue's 4 inch offerings range from $2,200 to $3,000 (not including a mount). Astro-Physics 4.1" sells for about $2,150 (again, no mount).
Once you move up into the 5" and higher class of instruments, prices really begin to shoot up.
Meade has a line of APO's which they have priced very attractively. I have not heard stellar reports on the quality of the optics, however, so my best advice is to proceed with caution when considering them. Approximate prices: 5" is $2800, 6" is $5,000, and the 7" is $6,000. (GEM and field tripod is included in the price). A computerized drive system can be added for $800.
TeleVue Tele Vue Table of Contents has only one current offering above 4", the TV 140.
Astro-Physics is perhaps the king of the APO refractor, and they have prices and waiting times that reflect it. Their 5.1 inch scopes range from $2,700 to $3000 (without mount). The 6.1 inch models range from $4,500 to $6,400, and the 7.1 inch from $6,000 to $8,200 (again, no mount included).
But even Astro-Physics can't lay claim to being the most expensive. Takahashi offers a variety of 5", 6", and 8" scopes, all of which come with mounts. Prices: the 5 inch model is $8,200. The six inch models range from $13,200 to $18,700. The eight inch f/10 model, believe it or not, comes in at a whopping $168,000 (and you can't even sleep in it).
Wrapping up.......
I hope that this page has wet your appetite for pursuing astronomy in earnest. I also hope it has painted a picture of what the telescope market looks like today. As you can see, there are a great many options, depending on your lifestyle, budget, observing interests, and need for portability.
As mentioned previously, your investment will not stop at the telescope itself. There are a slew of accessories that you will need for your scope. You will find more in depth discussion of the these on my page dedicated to people who are rediscovering astronomy for the second time in their lives.
Good luck in your hunt for the perfect telescope. If you think that there are any key telescopes that I have missed in my review, please drop me an E-mail and let me know. I'll be glad to add them to the mix.
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