Buying And Using A Telescope
Buying a telescope is a big decision. Here are a few tips to get you started.
Advice for First Time Telescope Buyers
What’s on the top of your Xmas list this year? Maybe a telescope? You know, I get a lot of people asking me what’s the best telescope to buy. Well, the short answer is the dearest one you can afford. Modern telescopes are a compromise between price and quality and any telescope in this country under AU$250 is not going to do any serious work for you. Buy from a dealer who knows about telescopes, a camera shop for instance, or a telescope retailer.
This page will answer some basic questions consumers often have when purchasing (or contemplating the purchase of) a first telescope. The contents of this page applies to small to medium sized, beginner (or “first”) telescopes. By small, I mean 2.4 inch (60mm) to 3 inch (or 75, 80 and 90mm) refractors, and 4.5 to 6 inch (100-150mm) reflectors (6 inch telescopes are generally thought of as “medium” sized). Telescopes in this beginner class typically sell for $150 to $600. Quality starter telescopes are available from a number of manufacturers.
The buyer should be aware that there are many very poor quality telescopes in the marketplace; these are most often found in “department stores”. It is hoped that the information on this page will help out prospective new astronomers and to advise them not to expect too much from a small telescope. If you have any questions, please send e-mail to firstname.lastname@example.org and I’ll try to help! First…BEFORE you buy a telescope! Many amateur astronomers will tell you that the best way to get into astronomy is to first learn the constellations, and then use a pair of binoculars to find your first “deep sky” objects.
It is important to learn the basics of finding your way around the sky (you will need these skills to find objects using a telescope). Binoculars really can show quite a number of interesting sights in the night sky. A good pair of binoculars will often cost less than a telescope; in fact, if your budget only allows spending about $150, you’d probably be better off buying a decent pair of binoculars and a good book rather than a telescope. Most experienced amateur astronomers agree that “jumping in” with a fancy telescope without first learning the basics is not the way to get involved. Astronomy is a fascinating hobby but it’s not for everyone.
If you “jump in” and spend $1000 on a fancy telescope and then later find you’re not really into it, you will have wasted a considerable amount of money (but on the positive side you will have created a “great deal” for another amateur astronomer who is eager to buy your “dust collector”!). My advice is to start small and work your way up to a telescope. Another great way to start in astronomy is to visit a local astronomy club (most cities have some kind of club). Clubs often have loaner scopes, or at minimum, there will be members that will be happy to show you a number of telescopes. However, if you do want to start out with your own telescope right away, at least read the rest of this article!
Number One: Have realistic expectations!
DON’T EXPECT a small telescope to show images like those you may have seen in magazines. Those pictures are likely from the Hubble Space Telescope or some other large professional telescope. If you are expecting “video game” type images with amazing detail and colour, you will likely be in for a letdown. One target that will show tremendous detail (even in a small telescope) is the Moon. Even a telescope as small as 2.4 inches (60mm) will reveal a wealth of detail.
You’ll be able to see craters, mountains, “seas”, and a number of other fine details. As far as planets are concerned, only a few will show reasonable detail in a small telescope. On Jupiter you can see cloud bands, maybe the Great Red Spot, and 4 of the large moons. Jupiter is the planet that consistently shows the most detail in amateur telescopes. However, even at high magnification Jupiter will only look about the size of some of the medium sized craters on the Moon. Saturn will show its glorious rings, although at present they are side on and hard to see and keen eyed people (with good seeing) might also spy some cloud bands. Saturn’s largest moon Titan will also be visible but only as a moderately bright dot. Venus will be easily visible, but no surface detail will be seen since the planet’s surface is permanently hidden by a thick, white atmosphere.
You will be able to see the phases of Venus quite easily however. Mercury is too small and too far away to see any surface detail, and is often not visible due to its proximity to the Sun. If you can find Mercury (which generally can only be seen in twilight conditions), at best you will see only the planet’s phases. Mars is easily seen in a small telescope, but only shows detail when it’s close to Earth. Due to Mars’ orbit, it only “puts on a show” every few years. When it is close to Earth, you might see a white polar cap, and perhaps some surface markings. The biggest problem with Mars is that it’s a small planet. Uranus and Neptune can be seen in a small telescope if you know exactly where to look.
You’ll need to have a finder chart to locate them. Even very large telescopes show them basically as small green and blue dots. No surface detail will be visible. Pluto is out of the question for a small telescope; it generally requires an experienced observer using at least an 8 inch telescope (in a dark sky with a highly detailed finder chart) just to see it as a very faint dot! In addition to planets and the Moon, there are a number of other objects within the reach of a small telescope. These include galaxies, star clusters, nebulae, and double stars. However, the quality of the view you will have on these kinds of objects depends to a very large degree on how much light pollution you have in your area (more on light pollution below).
To locate most of these objects you’ll have to use a star atlas (first you’ll have to learn the basic constellations in order to find your way around the sky). Again, don’t expect to see galaxies and nebulae like they appear in most magazine photos. Most galaxies and nebulae appear as “fuzzy patches of light” in small (and even large) telescopes. Star clusters and double stars are often quite beautiful and are good targets for small telescopes. You can also look at the Sun with a small telescope, however you MUST USE A SPECIAL FILTER FOR OBSERVING THE SUN WITH ANY TELESCOPE. Failure to do so will result in instant and permanent blindness.
DO NOT attempt solar observation unless you are sure you have the correct special equipment AND you know proper procedures. Solar observation is safe if you adhere to proper procedures! You can see sunspots and solar “granulation”. If in doubt about observing the Sun, have an experience amateur astronomer with you prior to solar observing… your eyesight is at stake!
Number Two: Don’t blame the telescope for things it can’t control!
Many beginners don’t realize that a telescope’s performance is often at the mercy of ambient local conditions and sky conditions. Other than the obvious (clouds, fog, etc.), there are several other major factors which limit how much can be seen. First, it is very important to give a telescope a chance to cool down to the outside temperature. This is called thermal stabilization. If a telescope is brought from a warm house out to a cold night, the images seen through it are likely to be very bad at first, perhaps to the point where the telescope won’t even seem to focus at all.
This is because the optics in the telescope are undergoing a change in size due to the temperature difference. The actual change in the optics is extremely small in human terms; however, at the wavelengths of light, it is very significant. Bottom line: Make sure a telescope has time to cool down to the outside temperature before expecting it to perform at its best. Acceptable performance is usually reached with 15 to 20 minutes, but the very best performance may take one hour or more (depending on the temperature differential and the type of telescope). Storing a telescope in an unheated garage may help to shorten the time it takes to cool; alternatively, set the telescope outside an hour or so before you plan to use it.
Keep in mind that even after it has cooled down the images still may not be too good. This is often due to the topic of the next paragraph, seeing conditions. Second, seeing conditions are very important for good viewing (especially so for the planets and the Moon). When you look at an astronomical target, you are seeing it through the Earth’s atmosphere, which essentially is an “ocean of air”. Very often the atmosphere is highly unsteady, due to thermal variations, air currents, etc. All of this means that an image passing though it will be distorted to some degree. Have you ever looked over a toaster while toasting some bread? The image of objects behind the toaster seems to shimmer. Now, imagine looking through miles of turbulent air at high magnification! In short, bad seeing conditions can severely limit the amount of fine detail you can see (fortunately bad seeing has much less effect on galaxies, star clusters and nebulae).
On the down side, nights of “truly” good seeing are fairly rare. You may have to observe for a dozen nights before you happen to get a night where the air is very steady! The third big (and rapidly growing) problem facing astronomers is light pollution, a problem that is unknown to most non-astronomers. Light pollution is caused by excessive amounts of and/or poorly designed outdoor lights. Light pollution will not affect the viewing of the Moon and planets, but it can seriously limit the number of non-solar system objects you might otherwise see (objects such as galaxies, star clusters and nebulae). Light pollution has invaded almost all populated areas of the country. Often, the only remedy is to drive to a dark location, generally 10 to 30 kilometres or so from any major city (and even at this distance some evidence of light pollution may be quite visible). For more information on light pollution see the International Dark Sky Organization’s web site at http://www.darksky.org/.
Number 3: Use LOW magnification, and make sure your scope is properly adjusted!
Most beginning astronomers think that high magnifi cation is they key to great viewing. This is a common misconception. Any experienced amateur astronomer will tell you that most observing is performed using low magnification. For small telescopes, low magnification (or “power”) means anywhere from about 20x to about 50x. High power is useful (and often necessary) for viewing planets and double stars. However, initially finding a planet (or any object) is much easier with low power. Even users of large telescopes use mostly low power.
The most magnification that is useful in a typical small telescope is in the range of 100x to 200x (for ‘scopes in the 6″ range). Small telescopes do not gather enough light for satisfactory high power views of galaxies and nebulae. So, resist the temptation to “go to high power”! Stay with low magnification for most objects, and you will see much more! Getting quality images in a reflecting (Newtonian) type telescope is very much a function of the alignment or collimation of the optics (misalignment is common among reflecting telescopes but almost never an issue with refracting telescopes). If the optics are out of alignment, you will still “see” through the telescope, but very likely the images won’t focus properly, or the image will seem very distorted.
Most telescope manuals provide instructions on how to collimate the optics. It can be a bit tricky; do the initial alignment indoors (fine tuning can be done outside at night). Collimation tools are also available cheaply and are a great help in aligning the optics. Optics do need to be checked for alignment from time to time, especially if the telescope has taken a bumpy ride in the back of a car (for example). If you want to eliminate the “maintenance” associated with telescopes, buy a refracting telescope.
Number 4: Telescope Quality
As far as beginner telescopes are concerned, there are many “junk” telescopes out there, and then there are some decent starter scopes which are not too expensive. Expect to pay at least $250 for a quality beginner telescope in Australia. You can find scopes for around $100 or less, but beware. They often make claims that are preposterous, and are of very poor mechanical and optical quality. You are better off buying a simple (but well made) telescope. In other words, buy a telescope where the money has gone into basic functionality (good optics and a good mount).
“Junk” telescopes are easily identified, since they come “standard” with numerous (but often useless) accessories! [If you want to skip all this and just want me to tell you a good scope to go and buy right now see my comments at the end titled “When All Else Fails.’] Of paramount importance in any telescope is optical quality.
While a beginner telescope cannot offer “custom hand made and certified state of the art optics”, ones from reputable manufacturers are generally quite satisfactory. Stay away from “department store” telescopes!!! As good as they are with other things, they usually don’t know much about this sort of product. Buy from a dealer who knows about telescopes, a camera shop for instance, or a telescope retailer. The very worst telescopes have plastic lenses… needless to say, these units will have extremely poor performance.
Perhaps the second most important part of a telescope is its mount. There are numerous types of mounts (beyond the scope of this article). They key is to make sure the one that comes with the scope you’re considering is smooth, stable, and solid. Few things in Astronomy are more frustrating that fighting with a poor telescope mounting in the dark! Poor mountings will make using high magnification especially annoying and frustrating. Purchase a telescope with a simple (but quality) mount rather than a cheaply made “advanced” mount! If you can pick the entire scope and mount up with one hand it will wobble in the slightest breeze and you will invent words never heard before ? One of the important items that come with a telescope are the eyepieces. The eyepieces allow you to change the magnification of the telescope.
Many “trash” telescopes provide a worthless Barlow lens, 3 or 4 virtually worthless eyepieces (many of which result in a magnification well beyond the useful capability of the scope). For small beginner telescopes, it is much better to have one or two quality eyepieces (as opposed to a battery of junk eyepieces). One eyepiece that produces low magnification (say 30x or so) and one for high magnification (about 100x) is the best bet for a beginner. Eyepieces are marked with letters and numbers; these characters denote the optical design of the eyepiece and the focal length of the eyepiece. Beware of telescopes that have eyepieces with any or all of the following markings: H25, H20, H12.5, and SR4.
If the scope has one or more of these eyepieces, it is likely that the images will be marginal to poor. The “H” stands for “Huygens”, one of the poorest performing optical designs ever made (they are inexpensive to manufacture however). “SR” stands for Symmetric Ramsden. Trust me on this: no small telescope will benefit from an SR4 eyepiece. The manufacturer simply includes this so that the high end magnification of the telescope sounds very impressive (in reality you will be lucky to see anything through an SR4 eyepiece). The SR4mm eyepiece has what is known as very poor eye relief.
If you wear glasses, the SR4mm eyepiece will be impossible to look through. Eyepieces with poor eye relief require that your eye be very close to them, often uncomfortably close even for those with normal vision. The bottom line: Any telescope will have sharper and brighter images when LOW magnification is used. And, finding objects will be MUCH easier!
Number 5: What Brand Telescope is Good? In the beginner telescope market, this question has become clouded in recent years. Meade and Celestron are two major manufacturers of telescopes; in years gone by all the telescopes offered by these companies were good to excellent. Meade and Celestron have made a much bigger presence in the “consumer” telescope market in the past few years. In the 1970’s, if you owned a Celestron telescope, you owned a good telescope (period).
Back then, all of their telescopes (about 4 models) were American made. Today, both Meade and Celestron have entered into the low end telescope market, and both companies tend to “distance” themselves from admitting this fact. Both Meade and Celestron still make some outstanding products; the problem is, the good ones are found less and less frequently in consumer outlets. Meade has been marketing telescopes under the “Saturn” brand; these scopes are ones that are “jazzed up” with lots of trashy accessories and a very eye catching package (no doubt to lure parents into purchasing the units).
If you want a REAL telescope, my advice is to steer clear of these telescopes. So, what does all this mean? Meade and Celestron still do make some very nice starter telescopes, the key it to get one of the “real” scopes. Orion Telescope and Binocular also offers a number of very nice starter scopes. If you are not sure about a telescope model ask the advice from your local astronomy club.
Number 6: ‘GO TO’ Telescopes
GO-TO telescopes (Inbuilt Computer Controlled) that are available in the low priced market have shown some level of quality control (with regards to the GOTO functions). I grew up in the “old school” of amateur astronomy, that is, I learned the sky and learned to “star hop” to objects I wanted to observe. GOTO telescopes do have some remarkable capabilities however. They can allow you to locate a great many objects (often way more than the scope has a chance of seeing) in a short time. However, there is a drawback.
While a GOTO scope can locate objects for you, it denies you the opportunity to learn your way around the sky. A GOTO scope is kind of like a car that takes you to any address you specify, but with no knowledge (or view along the way) of how to get there. With the star hop method, you learn to recognize star patterns and often you see interesting things along the way. I do recognize that some people do like them a lot, and for some applications they can be quite helpful.
For example, if you have light polluted skies, it may be hard to use the “star hop” method of locating objects because there are not many stars that can be seen (necessary for star hopping). A GOTO scope will find things for you even if there are few stars visible to the naked eye. However, if your skies are particularly poor, don’t expect to see much through the main scope either. Another thing about GOTO scopes: there is more stuff to act up and break down.
A simple scope with a basic mounting is for all practical purposes a lifetime instrument, there are few if any parts that will ever wear out or stop working. But hey, hit a few numbers and within 30 seconds you’re looking at the object you want – not bad you know!
Number 7: Where to buy a Telescope There are a number of places to buy a telescope… however I advise against purchasing a telescope at a department store! Typically, there will be several telescope models to choose from, most in the $100 – $200 range. Often, these outlets will have a Meade ETX and/or Meade LX200 scope nearby, costing about $600 and $2000 respectively.
There’s a reason these scopes cost a lot more than most of the models… they are good scopes! In supermarkets all of the scopes I have seen there are not ones I would recommend. Oh, I’m not classing places like Dick Smith or tandy in this bracket… but watch them too for the cheap & nasties. Another good place to purchase a telescope is through mail order. The best way to see what’s available via mail order is to pick up a copy of a good astronomy magazine.
All are loaded with mail order ads from many companies and distributors. A great deal more selection is available via mail order than through any other source. The downside is that you can’t check out the ‘scope firsthand, you’ll have to wait for it. Again, look for the classic sign of a low end telescope: eyepieces marked H25, H20, H12.5, and/or SR4 along with a long list of accessories and a fancy box covered with pictures (which were probably taken by a large professional telescope).
If you see any of these, I recommend that you look elsewhere! Some of the very best telescopes arrive in plain old brown cardboard boxes.
I’ve got $500 to spend… What’s my best bet?
As mentioned at the beginning of this article, it’s best to first learn the constellations and to have located various objects using a pair of binoculars. If you’ve done this and you have a thirst for more, you are ready to move up to a telescope. In my opinion, $500 is probably a good amount to spend to get a truly decent starter scope and the necessary accessories you’ll need to round out the package.
Most astronomers will tell you to buy the biggest scope you can afford, and I generally agree with this statement. With a $500+ budget, my personal recommendation for a starter package would include a 6″ Dobsonian reflector telescope. A 6″ scope is big enough to show good detail on numerous objects, and yet is quite portable. If you’ve got an extra $100 or so to add to your budget, you can move up to an 8″ Dobsonian reflector, a very capable telescope that could even be with you for a lifetime of observing.
If you can only afford $250 or so, a smallish 4.5 Dobsonian or newtonian telescope is probably the best bet. Although not as capable as the 6″ scope, it is a decent starter scope and it did get a decent review. Sometimes you can find deals on scopes for even less money. EBay is another source for telescopes, but you are at some risk (you have no assurance that the scope is not damaged, etc). Every once in a while you can find a nice scope at a tag sale, but you need to know enough about the unit to decide whether it is worth the cost.
People who have good scopes know what they have, and they will not show up for $25 at a tag sale! As mentioned previously, local astronomy clubs might be your best option to get introduced to a telescope. You may be able to get a loaner scope from a club, one that might cost a lot more than you might want to spend. Also, should you find you are not into astronomy, you can always turn the scope back in and no money is lost.
PLEASE DO NOT BUY ONE OF THESE!!!!!
“Today’s Deal – Reflector Telescope with Tripod Price Slashed! Regular Price: $69.95 * For a limited time only, while stocks last.
USUALLY ADVERTISED IN A CATALOGUE OR ON A DISCOUNT WEBSITE – THESE ARE ‘NASTY’ TELESCOPES OF POOR DESIGN & QUALITY
The advertising says, “Light weight and reasonably compact, this Reflector Telescope is great for viewing remote galaxies, nebulae and star clusters.” It isn’t and it won ‘t! Seen mainly in discount stores and department stores. This is a toy telescope – remember that.
(Pic:Top right) It is a very small aperture telescope, no better than binoculars. The tripod is lightweight and flimsy – watch it wobble in the slightest breeze. The eyepieces are the lowest quality available. They give you a Barlow Lens which is useless on this size telescope and the whole unit is made of thin aluminium.
Once purchased you’ll get reasonable looks at the Moon but then what….? Nothing. The planets will look like bright dots and when you try to magnify them they’ll turn into bigger blobs of light, fuzzy and indistinct. Same with this ‘package deal’
(Pic: Left) It’s a package alright, but it definitely isn’t a deal. These telescopes would suit a 5 year old kid… but nothing more than that. Flimsy, lousy optics, cheapie lenses, you name it. Put your money towards something better. Look at the magnification claim – “up to 525 power.” In reality, anything over 60x power and the image would start to.look like an indistinct blob! You have been warned OK.
Some other thoughts… It is important to keep in mind that small (and even large) telescopes will not provide visual images like those seen in books and magazines (the Moon is a possible exception). For many objects, you must take satisfaction in just knowing that you have barely detected a faint smudge of light!
Only a few of the brightest objects will be considered impressive by the average person. If you go into astronomy expecting brilliant, colour filled views of objects in the sky, you will likely be disappointed. Amateur astronomy is not about dazzling “video game” graphics and Hollywood special effects. Amateur astronomy is not unlike learning to appreciate fine art; you must learn to appreciate what you see in your telescope, which in many cases will only be a very faint patch of light.
Even though you might be only able to just barely glimpse a faint galaxy, know that you are seeing an incomprehensibly small portion of the light generated by a billion suns, light which has travelled a journey of unimaginable distance, a journey lasting many millions of years! This light found its way into your telescope and into your eye.
When you look at a distant planet in a telescope, you are seeing the real thing, live, and you can be sure that only an extremely small fraction of people on Earth are looking at the same object at the same time! You will not be able to see anything close to the American flag on the moon.
However, you can look at these distant objects like the Moon, the planets and galaxies, knowing that you (nor anyone else) will likely never visit them in person, and wonder what it might be like if you could actually personally visit them. You also know that these objects are countless times older than any person alive, and that they will still be there long, long after Mankind has ceased to exist on Earth.
When all else fails
If, after reading all this stuff, if you are still confused and say to yourself, “Heck, I just want to buy a good quality, basic telescope for a casual poke around the sky and maybe a bit of whale watching too,” then head to your camera shop or telescope dealer and buy a 70mm refractor. You’ll pay no more than $299 from us for this telescope complete with tripod, eyepieces and accessories. They are a great telescope with very good optics. (plus we give you some good advice and guidance free) I use one… a 70mm refractor. Click Here. In no time at all you’ll be an amateur astronomer.
Indeed, Galileo himself began as an amateur astronomer, pointing the recently invented telescope toward the night sky out of sheer curiosity. Coincidentally, next year is the International Year of Astronomy celebrating 400 years since Galileo’s discovery. Watch for events happening all around the world. Now, if you get this silly urge to wave up at the astronauts when you are watching the International Space Station pass over you – give in. I do it every time. How do you see it? Just visit www.heavens-above .com.
Heavens Above is a fantastic site for the amateur astronomer. Just choose your city from the database, and you’ll be able to get all the information you need to spot the space station and a few satellites zooming over the coast.
ObservingTips Whether you stargaze with the naked eye, binoculars, or a telescope, there are some simple procedures that will help you get the most out of your vision. These basic tips are geared toward making the most of the faraway stars’ faint light.
Adjust to the dark. This is especially useful if you plan to view faint objects — and most sky objects are faint! To achieve maximum sensitivity, wear sunglasses whenever possible when outdoors, especially for the last few days before an observing session. Spend at least a half-hour in subdued light before your observing session. Use dim lamps to study charts or maps; red light will help preserve your night vision.
Give yourself time Let the image “build” on your retina. The retina is able to “store” light for brief periods. Take advantage of this by keeping your eye as still as possible. Allow the faint object’s light to continuously strike the same portion of your retina for up to five or ten seconds. Look to the side of faint objects. Because of the way our eyes are constructed, it’s difficult to see faint objects in the central field of vision. Averted vision lets you study the faintest possible detail using your peripheral vision; you can see fainter detail if you don’t look directly at the object. With the right eye, try looking just to the right of the faint object. When using the left eye, look just to the object’s left. It seems quite difficult at first, but soon it will become second nature.
Photography: If you intend taking photographs you’ll need a camera adaptor, camera shops like Camera House have them and they’re reasonably cheap. Remember to bracket your shots and use a selection of time exposures. Old SLR‘s are good for this type of thing.
SO … NOW YOU’VE BECOME AN ‘EXPERT’
Well, sort of. That’s a good move! Here’s the 8-Step Rule: 1. The diameter of the objective lens or mirror is the most important number describing a telescope. Larger diameter lenses or mirrors allow higher resolution (ability to separate closely spaced objects) and will gather more light from faint astr onomical objects. They also cost more.
2. Magnification is relatively unimportant and is often hyped in advertising claims for inexpensive telescopes. In astronomy, the purpose of a telescope is mostly to collect light from faint objects, not to magnify them.
3. Too much magnification just gives you a useless blur. A good rule of thumb to determine the maximum usable magnification is to multiply the diameter of the objective in millimeters by 2.5 (which means that the typical department store 60mm scope is only usable to 150x). In actual practice, on nights of extremely unusual atmospheric stability, you -may- be able to use a somewhat higher power, but don’t count on it.
4. The better eyepieces have larger “eye relief,” which represents how close you have to get your eye to the eyepiece to observer clearly. If the eye relief is too small you will have to bring your eye very close to the eyepiece, and it will be all but impossible to observe for more than a few seconds at a time.
5. Look for a steady mounting, an unstable or shaky mounting will ruin your observing experience. In general, the more massive the mount looks, the better it performs. When in doubt, spend more on a mount.
6. Join an astronomy club and learn to use someone else’s telescope before buying your own.
7. Start with a pair of binoculars and learn to find things in the sky before buying a telescope. 8. Don’t expect a small telescope to show the same images that you see in astronomy textbooks, which are usually long time exposures and may have been taken by much larger professional grade telescopes.
Remember: For best results, look through a telescope in a dark place. In a city, you’re not going to see much. There are special eyepiece filters available to help reduce light pollution from streetlights, but they are not dramatically effective and are expensive. Consider getting an auto star telescope — it will find things for you to look at and prevent you from endless searching. Even with these “GoTo” scopes, you still have to be careful in leveling the tripod and picking the right bright stars to perform alignment on.
You typically have to choose two or three bright stars to align on so that the telescope knows where on Earth it is situated. Try to get a reflector telescope for best viewing — a refractor is fine as well. Reflector telescopes are much cheaper for a given objective size, but to perform at their best they require regular collimation–making sure the internal mirrors point perfectly straight down the tube. There are special eyepieces (called “Cheshire” eyepieces) that are inexpensive and make collimation much easier.
Contact your local planetarium if you have further questions about buying a telescope. They will be happy to guide you to local and mail-order dealers who are reputable. Don’t buy a $200 eyepiece to get a higher power, instead, spend it on a better scope. See a range of good recommended beginner and advanced scopes at my page here: Telescopes for Beginners
A Review of The SkyLaser 125Mw Green Laser Pointer
Exploring the night sky can be fun. Armed with just a star map and binoculars you can literally spend hours ‘out there’ getting lost among the stars, and sharing it with others makes it even more pleasurable. Add a telescope and the night really gets interesting. It’s funny how people react when they see someone gazing up at the night sky through a telescope. It becomes addictive, an itch you can’t scratch, because they think they might be missing out on something.
Being an astronomy educator and media science correspondent pointing things out in the night sky to large groups of people has not been easy though – that is, up until now. Over the years I’ve tried a number of laser pointers with limited success. Then Chris Chen of the Californian based company SKYLasers heard of my plight and sent me one of their new high power 2010 green laser pointers to try out. Nicely boxed and with two AA batteries, I assembled the unit and headed outdoors.
I pointed it skyward, pressed the switch and was immediately transfixed! A solid shaft of vivid green light shot up into the night sky in a scene reminiscent of Star Wars. It looked like a bridge of light you could actually walk up… well, almost. Even in dim early evening light I could see the beam clearly, something other lasers I’ve used didn’t do.
After 30 or 40 minutes of constant on and off use the beam was as bright as when first I first used it. Very impressive! This is, without doubt, one of the most incredible products I’ve ever used. Ever! SKYlasers are FDA certified and a leading manufacturer of high power laser pointers, portable lasers and lab laser systems. They have an impressive range to choose from as any visit to their website will tell.
The higher powered models are renown for their burning capabilities and as Chris explained, the new models also come with Dual Lock Technology. The laser pointer will work only if both keys are inserted into the laser pointer. Very handy if you have kids around. I was sent the 125Mw model to test – but don’t tell them, I’m not sending it back!
Outdoors, you can trace a path across the sky and show people the ecliptic, the imaginary line the Sun follows in its daily journey from one horizon to the other. It’s easy with one of these pens. Run a ring of light around a large constellation to show its size and relation to other nearby star groups or pick out that elusive double star from the surrounding clutter. The sky literally is the limit!
Oh, one last thing. When mounted to a telescope, the laser pointer functions as a wonderful finder with unique advantages. I can tell you, for directionality “it’s out of this world”. Thanks Chris, you’ve changed my astronomy education program forever, for the better! SKYlasers at www.skylasers.com – see them, you won’t be sorry!