The New Scope Owner

One of the greatest flaws with these scopes, whether alti-azimuth or equatorially mounted, is the sturdiness of the mount. A mount that shakes at the mere touch of your hand while focusing, for example, will be tough to use. The higher the magnification you use, the more vital it is that you have a stable mount. When you apply magnification, it isn't just the image you are magnifying. Every wobble and shake is magnified as well! If you have found that your scope has the "shakes", here are a few things you can do:

1) Make sure that all of the hardware on the mount is tightened up and secure.

2) If you have an equatorial mount, make sure that you adjust the counterweight and tube position so that the telescope is balanced (i.e., if you unlock the clamps, the scope doesn't swing wildy like Quasi Moto from the bell tower).

3) If you are mechanically inclined, consider adding some cross bracing to the tripod legs.

4) Do not extend the tripod legs all the way out. The lower you keep the scope to the ground, the better.

5) Set your scope up on a surface that does not conduct vibration. The idea of observing off your second floor deck might be very appealing, but every move often sends shudders up the scope! Even setting up on concrete will cause some vibrations. Typically, setting up on a grass or dirt surface is best.

The greatest optics in the world are virtually useless on a poor mount. So make sure you take steps to make the best of the mount you have on your instrument. A good test:

Look at a bright object (the Moon is ideal) at medium magnification (about 50 to 75 X). While looking through the telescope eyepiece, give the leg of the tripod a good tap with your hand. You''ll see the image vibrate. They key is the length of time it takes for the image to stop vibrating. If it is 3 seconds or less, you probably have a mount that you can work with. If it is longer than 3 seconds, you are on ... well ... shaky ground!

If you have an alti-azimuth mount, you simply set the telescope up and you're ready to go. The mount can be placed on the ground in any position. As far as set up is concerned, it is the easiest of the two mounts for the beginner to use. The only down side (and it can be a frustrating one) is that the mount can get in the way of pointing the telescope towards the portion of the sky more directly overhead (the area of the sky known as the zenith).

For the equatorial mount to be used effectively, it has to be set up properly. This can be a very confusing task for the beginner. Basically, you have to point the polar axis of the mount in the same direction as the polar axis of the earth. If you do this properly, you only have to move the scope in one direction to keep up with objects as they "move" across the sky. When viewing objects at high magnifications of 150X or more, this can be a real advantage. To enjoy this benefit, you don't have to have the scope exactly aligned to the spot in the sky known as the celestial pole (i.e., the imaginary spot where the earth's polar axis points to). Pointing your scope's polar axis at the Polaris (a.k.a. the North Star) is plenty close enough.

When aiming the polar axis at the Polaris, you have to adjust it in two directions: left and right and up and down. The left and right is simple: with a small scope, simply move the entire mount so that the polar axis points in the correct direction. The up and down adjustment, which can be harder to "eyeball" without looking through the scope itself, is made by loosening a clamp of some sort on the side of the polar axis, which allows the axis to be elevated up and down. Once you get it pointed at Polaris, clamp it back down.

Here are a couple of shortcuts for adjusting the "up and down" portion of this procedure:

The exact angle of your scope's polar axis, stated in degrees, will match the latitiude coordinates of wherever you are observing from on Earth. For example, in Jacksonville, my scope's polar axis is aimed at an angle of 30 degrees (as measured from a horizontal plane). This matches the approximate position of Polaris (close enough for our purpose up to this point).

Your scope may have what is called a "latitude scale" somewhere near the polar axis. It consists of a series of ticks/lines in an arc, and perhaps has a needle-like indicator that moves as you raise or lower the axis. There are probably numbers inscribed on the scale, perhaps indicating every five, ten, or fifteen degrees. Assuming that the head of the tripod is level, all you need to do is loosen the polar axis clamp and adjust the tilt up or down until the needle points to your home latitude. This will put you pretty close to the mark.

Another method you can use, in the absence of a latitude scale, is to use a protractor to measure the angle, and set the polar axis accordingly. It'll at least get you in the ballpark.

Once you have set the angle of the polar axis, and have moved it either left or right to point towards Polaris, move the telescope tube so that it lines up right over the mount's polar axis. Take a look in the finder scope (assuming that you have lined it up with your main scope). Polaris should be visible. Fine tune the alignment of the mount so that Polaris is in the center of the field of view (don't move the tube itself). Once it is, you have notched one of your first victories!

This will get you close enough to enjoy the benefit of tracking an object. The farther your polar axis is lined up away from the North Celestial Pole, the more adjustments you will need to make in your Declination control while tracking. If you are dead-on in your alignment, you will only need to move the scope in Right Ascension during long periods of observing an object.

To use your setting circles, your alignment with the North Celestial Pole must be virtually exact. To complicate things, the North Star does not sit exactly on the North Celestial Pole.... it is actually about 3/4 of a degree away. More on that a bit later. Let's enjoy one victory at a time!

The Eyepieces

If you bought your scope without doing much homework, I'll keep my fingers crossed and hope that it came supplied with eyepieces that are 1.25" in barrel diameter. The alternative is the smaller .965" barrel. The smaller barrel (often referred to as the Japanese standard) used to be the norm on this class of instrument. It was rare indeed to find a department store variety scope that came with the "American" standard 1.25" eyepieces. That has changed over the last few years, however, and it is more and more common to find the 1.25" as standard equipment. This is a very positive trend for the hobby, in that the eyepieces are generally of much better quality.

Even if the 1.25" eyepieces supplied with the scope are of questionable quality, having a scope that accepts 1.25" eyepieces provides the ability for you to upgrade. If you stay with the hobby, you will probably purchase a number of eyepieces over time. As long as they are 1.25", you will be able to use them on virtually any telescope you purchase in the future. An investment in a quality 1.25" eyepiece usually lasts a lifetime. For some examples and prices of different types of eyepieces, visit the following sites:

Orion Telescope
astronomics christophers, ltd. Telescope and Binocular Mail Order
Meade Main Index - Meade Instruments Corporation
Celestron

So why are eyepieces important? For one thing, you can't observe the image without them (I know .... I'm getting a little too basic, aren't I ?). It is the eyepiece that provides the magnification of the image. The smaller the number on the eyepiece, the higher the magnification.

The quality of the eyepiece is critical to the final image. You can have the best telescope optics in the world, but if you have a crummy eyepiece, you'll have a crummy image! Among beginners, the quality of the eyepiece is often the most overlooked feature when buying that first scope.

There are many different eyepiece designs. The various designs provide different "fields of view" i.e., how wide the field appears. To demonstrate the "field of view" principle, form your thumb and index finger into a circle and look through it while holding the "circle" flush against your face. That is the widest possible field of view through your "hand eyepiece". Now hold your hand six inches away and look through the circle ..... a narrow field of view, isn't it?

At this point in the discussion, the exact design of your eyepiece(s) isn't important. Of much greater importance is the focal length of the eyepiece, due to it's role in magnification....... which we will discuss next.

Magnification

As mentioned previously, these scopes are often marketed with outrageous claims regarding the magnification they are capable of. You might wonder how they can get away with it. Well, the companies get away with it because it is not an outright lie. They almost always provide an eyepiece and barlow lens combination that delivers the advertised magnification. The reality, however, is that this level of magnification is virtually unusable in a telescope intended for astronomy.

A good rule of thumb regarding usable magnification is that a telescope can apply about 50X (power) per inch of aperture. For example, the maximum useful magnification for your 60mm (2.5 inch) scope would be about 125X. Now, please keep in mind that this is a very general rule. Several factors can cause the useful magnification on any given night, or of a particular telescope, to be somewhat higher or lower. In the 60mm example, maybe you could push up to 150X or even 200X. But trust me on this: the 675X shown on the box is out of the question for astronomical observations. You should set your expectations around the 50X per inch rule. If your scope manages to deliver a good image at slightly more than that, terrific! As you experiment with your eyepiece and barlow lens combinations, you'll soon discover for yourself the realities of the 50X per inch rule.

As I mentioned earlier, the smaller the number (focal length) on the eyepiece, the higher the magnification. Magnification is easy to determine: simply divide the focal length of the telescope by the focal length of the eyepiece. For example:

900mm Focal length scope
________________________ = 36 X

25mm eyepiece

Simple, right? The scope will often have the focal length stated either somewhere on the telescope, or perhaps in the owner's manual. It would be very rare for that information not to be provided. If it is not, but you know the f ratio of the scope and the size of the aperture, then you can still figure it out. How, you ask? The focal length of the scope is equal to the f ratio multiplied by the aperture. For example:

If the scope has an f ratio of f15, and an aperture of 60mm, then the formula for determining the focal length would be:

15 X 60mm = 900 mm focal length

Why is this important to know? Primarily so that you can calculate the magnification provided by each eyepiece (how else are you going to stay within that 50X per inch rule?)

By now, the light bulb may have gone off over your head, and you have figured out what the telescope's f ratio represents. If you guessed that it is the ratio between the aperture and the focal length, you are correcto mundo!

For example:

900 mm focal length
--------------------------------- = f 15
60 mm aperture

The barlow lens plays a unique role in the magnification game. Many department store scopes simply throw in cheap barlow lenses so that they can make those incredible magnification claims. The barlow lens is an extra set of optics which further multiplies the magnification. Barlows that double or triple the "power" are most common. So it's not unusual for the manufacturers to ensure the following arrangement is provided with that shiny red scope, simply so that they can make the claim of POWER. Here's how they do the math:

900 mm fl scope
-------------------------- = 225 x 3 = 675X
4 mm eyepiece

Possible? Certainly. The proof is in the math. But you will soon discover that such magnification is useless with a 60mm scope... and certainly is WAY above our 50X per inch rule of thumb.

But here's the great news about magnification. I've saved it for last, so that you can move forward not feeling too disappointed. When it comes to astronomy, magnification is way down the list of things for you to be concerned about! In fact, most of the objects in the night sky are best viewed with magnifications of less than 100X! Some of your most memorable views of the heavens will be at magnifications of less than 50X! So don't fret. One of the most important things for you to do with that new scope is to figure out the eyepiece and barlow combinations that are going to give you the practical magnification you'll need for your routine observing. If your scope came with several eyepieces, it is very likely that there is one eyepiece out of the bunch that will be your work horse. And that eyepiece will probably be your lowest magnification. With most common (i.e., department store type) 60mm refractors, plan on your valuable eyepieces being 10mm and above. The tiny 4mm is going to collect dust.

One more thing. That wedge shaped thing with the mirror in the middle. That's your star diagonal. It is designed to make observing a lot more comfortable. The only problem is that having that mirror thrown in can make your orientation a little confusing. Images will appear to be right side up, but left and right (a.k.a. east and west) will be reversed. Without the diagonal, everything is flip-flopped .... up is down, and left is right. But that actually is easier to work with. For example, if you are looking at the moon and comparing your view to a map of the lunar surface, you would simply turn the map upside down, and presto! The image matches. This isn't possible with the diagonal in place.

If you own a Newtonian telescope as your beginner's instrument, you won't have that concern (no diagonals are needed, due to the position of the eyepiece way up on the front end of the telescope tube). But for now, we are going to keep our discussion focused on our small refractor users, since they make up the majority of first time scope owners.

The Objective Lens

If magnifying the image isn't our main goal with the telescope, then what is? Simply put, your telescope is a light gathering machine. The larger the size of the main lens (a.k.a., the objective, or primary), the more light it gathers. The more light it gathers, the brighter the image appears. The brighter the images, the fainter the objects you can see, and the better you can see the objects that are bright to begin with!

The size of the objective lens also determines just how well an image can be resolved. It's early to get into the details, but suffice it to say that the larger the objective, the smaller a star image appears. The smaller that point objects appear, the crisper they appear, and they can withstand greater magnification (sort of like thinking about increasing the lines of resolution on your T.V.). This whole topic of resolution can get a bit complicated for folks new to the hobby, so I'll leave it at this top-line level for now.

Let it be said that the objective lens (or, in a reflector telescope, we would say the primary mirror) is the heart and soul of the telescope.

The Finderscope

A finderscope's purpose is very simple. It assists you in pointing Hubble Jr. in the right direction.

By definition, finderscopes are very low power telescopes. The magnification is usually fixed (i.e., there are no removable eyepieces). Magnifications between 5X and 8X are the most common. If you get much above 8X, the finderscope starts to defeat its own purpose! The amount of sky visible becomes too small to allow for easy finding and pointing.

The biggest concern regarding finderscopes doesn't have to do with the magnification. The problems with finders usually stem from their aperture!

Remember what we said about the size of the objective. The same thing applies to the finder. The bigger the aperture of the finder, the brighter the objects will appear. And when you are hunting for faint objects, you will want them to appear as bright as possible, won't you? So a larger diameter finder is desirable.

Medium and large aperture amatuer telescopes (let's say 6" and larger) often have 50mm finders. You might react to that by saying "Gosh, that's almost as big as my scope!" Well, it's highly unlikely that your 60mm refractor has a finder scope that size.

Most amateurs consider a 30mm finder to be pretty good for scopes up to 8" in aperture. So it should suit you just fine if that is what is mounted on your small refractor. A 24mm finder is borderline, and I think that you will find a 20mm finder to be a bit tough to work with. The quality of construction is important as well. Some manufacturers throw on very cheap, plastic lens finders. And by all means, I hope that you don't have the sort of "flip" finder shown on the scope at the top of this page. They are the absolute worst type of finder to put on a telescope.

Using the finder is simple. First, you properly align it with the main scope. This is best done during the daytime. Using your lowest magnification eyepiece, simply point the scope at an object very far away (say, at least a 1/4 mile... the farther the better). Lock the scope solidly in place. Then adjust the finder so that the crosshairs are locked on to the object that is precisely at the center of the main telescope view. Next, increase the magnification in the main scope, and fine tune the position of the finder to get it as exact as possible. During your first observing sessions, it is best to do all of this during the day. You will be able to see the finder set screws much easier, as opposed to fumbling around in the dark.

Once you are aligned, you are ready to go. Practice your finding on some terrestrial objects during the day. It'll get you used to sighting down the tube, and then through the finder. At night, start by targeting the Moon. As long as your finder stays in alignment, you'll be set. After you have mastered pointing the scope at a big easy target like the Moon, you'll be ready to tackle the planets and brighter stars.

Ready, Set......

WAIT! You are not ready to go yet! We need to take care of a couple of very important items.

First:

Never look at the sun through your telescope. Not using the proper equipment and/or techniques for viewing the sun can result in permanent eye damage.

Some manufacturers include solar filters that thread on to your eyepieces. Throw these away. They are outright dangerous to use with your scope. Remember what the objective lens does with light. It amplifies it. Think about what you did with a magnifying glass when you were a kid (you know, the ant thing). Well, you can imagine what type of heat is being generated by a 2 or 3 inch wide chunk of glass. Not only can this damage your main optics, it can damage that little thread-on filter on the bottom of the eyepiece. If that filter gives way while you are observing, you are running the risk of huge trouble. So don't mess around with it. There are safer ways to observe the sun that will protect you and your equipment. We'll get back to that at another time.

Second:

Even if your scope checks out well, has a mount as solid as a rock, and you have good quality 1.25" eyepieces, there are other things that may ruin the quality of the image. And they are out of your control.

The conditions in the atmosphere are a critical part of observing. If the air is turbulent and unsteady (like when you look down a road on a very hot day), it will be a lot tougher for you to achieve a clear, steady image in your telescope; particularly if you are trying to use higher magnifications on the planets or the Moon. Some nights can be so bad that it is not worth bringing the telescope outside. Some nights will be marginal. But some nights will be superb, when the air is calm and steady, and the images are crisp as can be.

The larger the aperture of the scope, the more sensitive it is to the atmospheric conditions. Another term used to describe the conditions is called "seeing". Amatuers will often rate the "seeing" during their observations. Several different scales have been used for rating seeing. A scale of 1 through 5, with 1 being extremely poor seeing, and 5 excellent, is commonly used. Other scales simply reverse this, with 1 being best and 5 being worst. There are also more elaborate scales, such as a 1 through 10 system. Suffice it to say for our purposes right now that "seeing" is a critical factor. Over time you will discover when to blame poor images on your scope and when to blame it on the "seeing" conditions.

Third:

Choose your observing site with care.

Where you set your scope up can be a critical factor. We already discussed the things to take into account when it comes to avoiding vibration. But just as important is making sure that you are avoiding local atmospheric disturbances that effect the image. For example:

Don't expect good results if you are observing indoors, and aiming the scope through a pane of glass in a window!

Don't aim the scope at a target directly over a roof that might be emitting a lot of heat built up from during the daytime. It will make the air very unsteady along your line of sight and might ruin the image.

If you are observing the planets and/or Moon, you don't have to worry much about local lights. These objects are very bright, and local lights won't interfere, unless they are very close to the line of sight.

If you are trying to observe fainter objects, such as nebulae or galaxies, getting away from lights is a must. And that doesn't just mean local street and house lights. If you live near an urban or dense suburban area, you have to contend with light pollution. Unfortunately, 20th century technology has taken away our pristine views of the heavens in most parts of the country. To find natural, dark skies, the average person often has to travel anywhere from one to three hours from home. In light polluted areas, the night sky simply is not as dark as in rural areas, so the faint objects .... and even the brighter ones.... simply get lost in the soup that is light pollution.

If you are going out to a dark sky site with your scope (and if you stay in this hobby, eventually you will) in search of the fainter objects, there are a lot of things that you need to bring along. I'll discuss those things in another area. But there is one thing that is critical, and that is a flashlight that only emits red light.

Once you get to your site, you want your eyes to become adapted to the dark. The larger your pupils are dilated, the more light comes in (sort of like your telescope). As you stay in the dark, it takes about 20 minutes for your eyes to achieve most of their adaption to the dark. You might see continued marginal improvement even past that point, but 20 minutes or so gives you the lion's share of the benefit. From that point on, you do not want to expose yourself to anything other than red light! You will not lose your dark adaption when using a dim red light. Any other sort of light will send you back to square one. Many beginners are not aware of this, and it's easy to blame the scope for not picking up objects when the truth is, you simply haven't prepared yourself for the hunt!

For more advice on how to prepare for a trip to a dark sky observing site, please visit my page on observing with Binoculars.

GO!!!

Whew! That was a lot to take into consideration before we even talk about what you are going to see with your first telescope. But now here we are, on the threshold of discovery. The universe is now at your beck and call. You've done your homework, and you are ready for action! Bring on those spiral galaxies! Show me those canals on Mars!! Point me in the direction of Neil Armstrong's size 10's!!!

WAIT ! Remember what I said about managing expectations? Well, here's where we start.

The small refractor (let's say up to 80mm), is particularly well suited for several types of objects. And not so well suited for others. Here's a run down on where it performs well, and where it doesn't:

The Moon has a unique beauty. Its appearance changes nightly as we watch first sunrise, and then sunset, march across the lunar landscape. The dividing line between night and day on the Moon is called the terminator. This area provides the richest level of detail visible on the surface at any given time. Long shadows cast over the lunar soil speak to the majesty of the peaks and the depths of the craters. With no atmosphere to speak of, and thus nothing to refract and scatter sunlight, one goes from instant daylight to instant night on the Moon. And we get to see it all from our perch here on Earth. Fortunate is the person armed with a telescope to do it!

When you observe the Moon, start by observing at low power. A map of the lunar surface is a must. It doesn't have to be anything elaborate. Just enough to name the major features. At low power, identify the major features from the map. As you observe the Moon during different phases, you will notice how drastically some of the features change. Even with a 60mm scope, you will be able to identify dozens if not hundreds of craters, all of the major mountain ranges and peaks, and all of the darker Mare. There is even more within your reach, once you study up on the geography of the Moon.

When Mars is closest to Earth, it can provide a sizeable target, revealing a fair amount of surface detail and weather activity in a moderate size scope. When at a further distance, Mars can appear appear so small that it looks like nothing more than an orange-red tiny disk. The once-every-other-year alignment with Mars is to be relished. When Mars and Earth are at the position in their orbits where they are both exactly in line on the same side of the sun, it is called "opposition". At opposition, the planet rises at sunset, and reaches it's highest point in the sky at midnight. Viewing is favorable for small scope owners for a period of about 2 months before and after opposition. During the time leading up to opposition, you can watch Mars' apparent size grow steadily, and more features, such as the polar caps and dark markings on the planet come into view. You might even see cloud activity on the planet. After opposition, as Earth speeds away from Mars, the size of the planet begins to diminish. This is usually the period of time when most casual observers watch Mars, however, since it becomes visible earlier and earlier in the evening.

This brings me to a key tip for observing the planets. It is imperative that you view the planets when they are high enough up in the sky to rise above the thick layer of air closer to the horizon. Generally speaking, planets should be at least 45 degrees above the horizon for your best view. This often means staying up late and waiting for them to rise, but it is well worth the wait.

The Association of Lunar Planetary Observersis an organization which specializes in the observation of... you guessed it.... the Moon and Planets. While the amateurs who contribute to this organization are well beyond beginner status (as are their telescopes), visiting this site might give you a good idea of just what is possible at the amateur level. Over time, as you gain experience and improve your equipment, you might one day make observations that rival and exceed those found at this site.

What else is out there?

I could go on for hours about the techniques of how to observe the objects I have described. But for now, it is perhaps best that I point you in the direction of some other resources.

There are two major astronomy publications that deserve your attention. Both of them feature monthly star charts and text that will point you towards celestial objects visible at that particular time of year. For a sample of both, go to Sky Telescope: The Essential Magazine of Astronomyor ASTRONOMY Magazine. Both are fine publications, and you will learn a lot from them.

Also, visit The Astronomy Club on AOL. At the main screen, you will find a number of resources that will help guide you to the stars. Among them is a list of astronomy clubs located across the country. Amateur astronomers are generally a friendly bunch and usually eager to offer advice, as well as a look through their telescope. It is to your advantage at some point to hook up with a group of amateur astronomers in your area.

And for those of you who are starting out with a 4.5" Newtonian telescope (another common beginner's scope these days, which provides a lot more bang for your buck than a 60mm refractor), I recommend a fellow AOL Observer's Outpost web site: Kevin Daley's Astro Nuts web site. He provides some great advice for that class of scope, along with some good illustration of what a variety of objects will look like when observed.

I would be remiss without suggesting a trip to your local library. There are any number of volumes at most libraries that a beginner would be able to devour.

I have a fair collection of astronomy Books on my shelf. Visit this page for my mini-reviews of several publications. Perhaps you will want to pick up one of them at your local book store, library, or book club.

For now, good luck among the stars!

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