One of the most surprising discoveries first telescope owners will find is that images may appear upside-down or backwards depending on the type of telescope. The first thought is the telescope is broken - when in fact it is working perfectly normal. Depending on the type of telescope images may appear correct, upside-down, rotated, or inversed from left to right.

Why is this? Why would I want to see everything incorrectly? For astronomical viewing, it is not important whether an object is shown correctly. In space there is no up or down. Besides, Saturn is not something you see everyday and you would not know if it was upside-down or not. A Tree, Building, Person or an Automobile for example would be important to see correctly. When you view an automobile upside-down, you recognize that this is not correct. Lets talk about the different types of telescopes and how the orientation of the image is observed through them and what you can do to correct it for land use.

Refractor and Cassegrain telescopes will produce an image that is upside down when used without a diagonal. When a diagonal is used the image will be corrected right side up, but backwards from left to right. It will look like trying to read a sign in a mirror. There are special diagonals called Erect Image Prism diagonals that can correct the backwards image for land use.

Newtonian Reflectors will produce an image that is upside down and are not recommended for land use. There are no ways to correct this with a Newtonian Reflector.

To a large extent, a telescope is only as good as its tripod and mounting. A telescope magnifies everything, including vibration. That's why many telescopes with decent optics are rendered useless when supplied on a cheaply made mount. The mount's adjustments should be smooth, yet precise, as you'll be using them to track the slow and steady apparent movement of stars. Smooth and precise movements - and a motor drive - are an absolute requirement for astrophotography.

A telescope mount has two functions - (1) Provide a system for smooth controlled movement to point and guide the instrument, and (2) support the telescope firmly so that you can view and photograph objects without having the image disturbed by movement.

There are two major types of mounts for astronomical telescopes: Altazimuth and Equatorial.

Dobsonian Mounts - A newer, modified version of the Altazimuth mount is called the Dobsonian mount. The Dobsonian mount was invented in the 1970's by John Dobson. A Dobsonian mount is mounted on the ground by a heavy platform. A Dobsonian mount was designed to support massively sized Newtonian Reflectors and keep a steady image from the size and weight of the optical tube. It is common for Dobsonian telescopes to have very large apertures - anywhere between 6 and 20+ inches!

Equatorial - Superior to non-computerized altazimuth mounts for astronomical observing over long periods of time and absolutely necessary for astrophotography. As the earth rotates around its axis, the stationary stars appear to move across the sky. If you are observing them using an altazimuth mount, they will quickly float out of view in both axes. A telescope on an equatorial mount can be aimed at a celestial object and easily guided either by manual slow-motion controls or by an electric motor drive to follow the object easily across the sky and keep it in view of the telescope. The equatorial mount is rotated on one axis adjusted to your latitude and that axis is aligned to make it parallel to their Earth's axis, so that if that axis is turned at the same rate of the speed as the Earth, but in the opposite directly, objects will appear to sit still when viewed through the telescope.

There are two basic types of equatorial mounts

German Equatorial Mount - Both Newtonian Reflectors and Refractor telescopes normally use this type mount. A large counterweight extending on the opposite side of the optical tube is its distinguishing feature. The counterweight is needed to balance the weight of the optical tube.

Fork Mount - Most Catadioptric and other shorter optical tubes use this style mount, which is generally more convenient to use than the German mount, especially for astrophotography. A more recent state-of-the-art computer controlled telescope allows fully automatic operation making it extremely fun and easy to locate objects while saving the observer considerable time and effort.

Unless the telescope is a tabletop model, it should be set on a tripod or pier-type platform. These must be rigid and minimize vibration. They should be portable and lightweight as well as easy to handle and set up. Appearance can be deceiving, as bulk and weight are not as important as a well-engineered tripod or pier.

Now many telescopes feature computerized electronic mounts with features that will automatically located and track objects in the sky. These telescopes automatically take you to thousands of objects in the sky and can even give you a guided tour! For more information see our article on Computerized GOTO telescopes and GPS telescopes

One of the best ways to get involved with telescopes and astronomy is to attend a Star Party in your local area. You would be surprised how close you are to an astronomy club or university that welcomes the public to observe. A Star Party is gathering of fellow astronomers with their telescopes - if you are going to attend a Star Party, it is important to understand some Star Party etiquette.

Rule Number One : Light Restrictions. You always want to be thinking that light is bad - from your cars headlights on the drive to the location or your flashlights for the walk-around. If you are setting up your telescope at a Star Party it is important to arrive early enough to get everything set up before dark. Telescope users spend a great deal of effort gradually adjusting their night vision for best visualization with a telescope. If you show up with a bright flashlight, you could potentially ruin someone's already adjusted night vision. Flashlights should be covered with red colored cellophane. It is a good idea to purchase yourself a good flashlight just for astronomy use. You can even coat the flashlight lens with some red nail polish for a more permanent effect. Many stores also offer red LED flashlight that last a very long time.

More about light : Most Star Parties will not allow campfires - so you will want to dress warm. The light from a campfire can greatly effect the viewing conditions - the smoke from a fire can ruin a nights observing very quickly.

Watch where you are going - It is important that you are very careful walking about from telescope to telescope. You never know what has been set down on the ground for a moment. You will want to be extra careful not to trip over tripod legs that may not be seen.

Music - Many Star Parties will have a list of rules or a check-in station depending on how large the event. Be considerate of others with loud music. Headphones may be the best idea.

Alcohol - The best thing to keep in mind about Alcohol at a star party is that the location may be in a park that prohibits consumption of alcoholic beverages. It is best to ask.

Keep it clean - It is important to take with you everything you bring. Including your garbage.

Star Parties can range from a small group of 2 or 3 casual observers to 50+ telescopes set up across a huge field. Many star parties will provide a list of basic rules and regulations. These are just some simple things to keep in mind.

If you're like most new amateur astronomers, the first thing you probably do when you get your new telescope properly assembled is put in an eyepiece and point it up to look at the moon. Just the excitement of seeing the lunar landscape up close is enough to keep you entertained for days. But eventually, as you progress to finding more difficult objects, such as planets and faint deep-sky objects, you will want to utilize all the features of your equatorial mount, such as the setting circles or perhaps even a motor drive. A mount is said to be "equatorial" if one of its two axes can be made parallel with the Earth's axis of rotation. Aligning the telescope to the Earth's axis can be a simple or rather involved procedure depending on the level of precision needed for what you want to do. For casual observing, only a rough polar alignment is needed. Better alignment is needed for tracking objects across the sky (either manually or with a motor drive) at high magnifications. Still greater precision is needed in order to use setting circles to locate those hard-to-find objects. Finally, astrophotography will require the most accurate polar alignment of all.

The polar alignment procedure works on one simple principle: The polar axis of the telescope must be made parallel to the Earth's axis of rotation, called the North Celestial Pole (NCP). When this is accomplished, the sky's motion can be cancelled out simply by turning the axis (either by hand or with a motor drive) at the same rate as the rotation of the Earth, but in the opposite direction. Although residents of the northern hemisphere are convenienced with a bright star (Polaris) less than a degree from Earth's rotational axis, the NCP can still be a somewhat elusive place to locate.

For ordinary visual observing, the telescope's polar axis must be aligned to the Earth's pole. This simply means positioning the telescope so that the polar axis is aimed up at Polaris. The easiest way to accomplish this is to rotate the telescope tube to read 90° in declination. In this position the telescope will be parallel to the polar axis. Now, move the telescope, tripod and all, until the polar axis and telescope tube are pointed towards Polaris. Finally, match the angle of your telescope's polar axis to the latitude of your observing location. Most telescopes have a latitude scale on the side of the mount that tells you how far to angle the mount for a given latitude (see your telescope owner's manual for instructions on how to make this adjustment). This adjustment determines how high the polar axis will point above the horizon. For example, if you live at 40° latitude, the position of Polaris will be 40° above the northern horizon. Remember your latitude measurement need only be approximate; in order to change your latitude by 1° you would have to move your observing position by 70 miles! Polaris should now be in the field of view of an aligned finderscope. Continue making minor adjustments in latitude and azimuth (side to side), centering Polaris in the finder's cross hairs or low power eyepiece. This is all that is required for a polar alignment good enough to use your telescope's slow motion controls to easily track a star or planet across the sky. However, in order to take full advantage of the many features of your telescope (such as setting circle and astrophotography capability) a more precise polar alignment will be necessary.

Before we can be certain that the telescope's polar axis is accurately aligned with the rotational axis of the Earth, we must first be certain that the finderscope (which will actually be used to polar align the mount) is aligned with the telescope's polar axis.

For polar alignment purposes, the finderscope itself can be used to accurately align the mount's polar axis by adjusting the finder inside its bracket. This is quite simple since the finder is easily adjusted using the screws that hold it inside the bracket. Also, the finderscope's wide field of view will be necessary for locating the position of the North Celestial Pole relative to Polaris. Here's how it's done:

Set up your mount as you would for polar alignment. The DEC setting circle should read 90° . Rotate the telescope in Right Ascension so that the finderscope is positioned on the side of the telescope tube. Adjust the mount in altitude and azimuth until Polaris is in the field of view of the finder and centered in the cross hairs.

Now, while looking through the finderscope, slowly rotate the telescope 180° around the polar axis (i.e. 12 hours in Right Ascension) until the finder is on the opposite side of the telescope. If the optical axis of the finder is parallel to the polar axis of the mount, then Polaris will not have moved, but remain centered in the cross hairs. If, on the other hand, Polaris has moved off of the cross hairs, then the optical axis of the finder is skewed slightly from the polar axis of the mount. If this is the case, you will notice that Polaris will scribe a semi-circle around the point where the polar axis is pointing. Take notice how far and in what direction Polaris has moved.

Using the screws on the finder bracket, make adjustments to the finderscope and move the cross hairs halfway towards Polaris' current position (indicated by the "X" in Figure B below). Once this is done, adjust the mount itself in altitude and azimuth so that Polaris is once again centered in the cross hairs. Repeat the process by rotating the mount back 180° , and adjusting the finder bracket screws until the cross hairs are halfway between their current position and where Polaris is located, and then centering Polaris in the cross hairs by adjusting the mount in altitude and azimuth. With each successive adjustment the distance that Polaris moves away from center will decrease. Continue this process' until Polaris remains stationary in the cross hairs when the mount is rotated 180º. When this is done, the optical axis of the finderscope is perfectly aligned with the polar axis of the mount. Now the finder can be used to polar align the mount.

So far we have accomplished aligning the polar axis of the telescope with the North Star (Polaris), but as any star atlas will reveal, the true North Celestial Pole (NCP) lies about 3/4° away from Polaris, towards the last star in the Big Dipper (Alkaid). To make this final adjustment, the telescope mount (not the telescope tube) will also need to be moved away from Polaris towards the actual NCP. But the question is; since Polaris makes a complete rotation around the Celestial Pole once a day, how far should the mount be moved and in what direction? Let's take an example: suppose you are out observing on August 1 st at 8:00 p.m.. A quick inspection of the northern sky will reveal that the last star in the handle of the Big Dipper, Alkaid, lies above and to the left of Polaris in the 10 o'clock position. Now, while looking through the finderscope (with Polaris still centered in the cross hairs) adjust the latitude and azimuth of the mount up and to the left until Polaris also moves up and to the left in your straight through finderscope. (Remember a straight through finder inverts the image, so Polaris will appear to move in the same direction as the mount is moved). How far to move Polaris will depend on the field of view of the finderscope. If using a finderscope with a 6° field of view, Polaris should be offset approximately 1/3 of the way from center to edge in the finder's view (i.e. half of the field of view, from center to edge, equals 3° and 1/3 of that equals 1° ). This calculation can be approximated for any finderscope with a known field of view.

The mount's setting circles can now be used to determine just how close the polar axis is to the NCP. First, aim the telescope tube (be careful not to move the mount or tripod legs) at a bright star of known right ascension near the celestial equator. Turn the right ascension setting circle to match that of the bright star. Now, rotate the telescope tube until it reads 2 hours 30 minutes (the right ascension of Polaris) and +89¼° declination. Polaris should fall in the center of the finder's cross hairs. If it doesn't, once again move the mount in latitude and azimuth to center Polaris.

This procedure aligns the telescope mount to within a fraction of a degree of the NCP; good enough to track a star or planet in a medium power eyepiece without any noticeable drift. However, long exposure astrophotography is far less forgiving and film will easily reveal even the smallest amount of motion. At this point, you may be wondering why bother polar aligning any more accurately if you can use the slow motion controls or drive corrector to keep a guide star centered in the cross hairs of an eyepiece. Unfortunately, keeping the guide star centered in the cross hairs is only half the battle. Since, the polar axis is not perfectly in line with the Earth's axis, the stars in the field of view will slowly rotate as you guide. You will get a sharp image of the guide star, but the other stars on the photograph will appear to rotate around the guide star. This is also why you cannot accurately do guided photography with an Altitude-Azimuth (Altazimuth) style mount.

The above method of polar alignment is limited by the accuracy of your telescope's setting circles and how well the telescope is aligned with the mount. The following method of polar alignment is independent of these factors and should only be undertaken if long-exposure, guided photography is your ultimate goal. The declination drift method requires that you monitor the drift of selected stars. The drift of each star tells you how far away the polar axis is pointing from the true celestial pole and in what direction. Although declination drift is simple and straight-forward, it requires a great deal of time and patience to complete when first attempted. The declination drift method should be done after the previously mentioned polar alignment steps have been completed.

To perform the declination drift method, you need to choose two bright stars. One should be near the eastern horizon and one due south near the meridian. Both stars should be near the celestial equator (i.e., 0° declination). You will monitor the drift of each star one at a time and in declination only. While monitoring a star on the meridian, any misalignment in the east-west direction is revealed. While monitoring a star near the east horizon, any misalignment in the north-south direction is revealed. As for hardware, you will need an illuminated reticle ocular to help you recognize any drift. For very close alignment, a Barlow lens is also recommended since it increases the magnification and reveals any drift faster. When looking due south, insert the diagonal so the eyepiece points straight up. Insert the cross hair ocular and rotate the cross hairs so that one is parallel to the declination axis and the other is parallel to the right ascension axis. Move your telescope manually in R.A. and DEC to check parallelism.

First, choose your star near where the celestial equator (i.e. at or about 0º in declination) and the meridian meet. The star should be approximately 1/2 hour of right ascension from the meridian and within five degrees in declination of the celestial equator. Center the star in the field of your telescope and monitor the drift in declination.

If the star drifts south, the polar axis is too far east.

If the star drifts north, the polar axis is too far west.

Using the telescope's azimuth adjustment knobs, make the appropriate adjustments to the polar axis to eliminate any drift. Once you have eliminated all the drift, move to the star near the eastern horizon. The star should be 20 degrees above the horizon and within five degrees of the celestial equator.

If the star drifts south, the polar axis is too low.

If the star drifts north, the polar axis is too high.

This time, make the appropriate adjustments to the polar axis in altitude to eliminate any drift. Unfortunately, the latter adjustments interact with the prior adjustments ever so slightly. So, repeat the process again to improve the accuracy, checking both axes for minimal drift. Once the drift has been eliminated, the telescope is very accurately aligned. You can now do prime focus deep-sky astrophotography for long periods.

NOTE: If the eastern horizon is blocked, you may choose a star near the western horizon, but you must reverse the polar high/low error directions. Also, if using this method in the southern hemisphere, the direction of drift is reversed for both R.A. and DEC.

Even with a telescope with a clock drive and a nearly perfect alignment, most beginners are surprised to find out that manual guiding may still be needed to achieve pinpoint star images in photographs. Unfortunately, there are uncontrollable factors such as periodic error in the drive gears, flexure of the telescope tube and mount as the telescope changes positions in the sky, and atmospheric refraction that will slightly alter the apparent position of any object.

Polar alignment, as performed by many amateurs, can be very time consuming if you spend a lot of time getting it more precise than is needed for what you intended to do with the telescope. As one becomes more experienced with practice, the polar alignment process will become second nature and will take only a fraction of the time as it did the first time. But remember that when setting up your telescope's equatorial mount, you only need to align it well enough to do the job you want.

Go outside at night and look up at the stars. You may not see many right away. But the longer you stay in the dark, the more stars you will see. This is because your night vision has improved. Your night vision will dramatically improve after about 10 minuets of being in the dark. You will be at your best night vision in about a half hour.

It takes time for your eyes to fully adjust for nighttime use. When your eyes have fully adjusted, it is very important to keep them that way. It will be important to stay away from light. For example, if you needed to go inside for something, it is best not to and ask someone to bring it to you. If you must, have some sunglasses with you and keep the lights to a minimum. It would be best however to avoid lights as if they would hurt you! Many avid astronomers will actually where sunglasses for a while inside before going outdoors - some will even where an eye-patch over their observing eye to preserve night-vision

While it is best to choose an observing area free from streetlights and city lights that is not always possible. Definitely turn off all the lights that you can, including house lights, garage lights - any lights you can. You want your observing area to be as dark as possible.

Maybe you have a park nearby that is farther away from streetlights and city lights; this would be your best choice for observing.

It is a good idea to own a red flashlight. Flashlights should be covered with red colored cellophane. It is a good idea to purchase yourself a good flashlight just for astronomy use. You can even coat the flashlight lens with some red nail polish for a more permanent effect. Many stores also offer red LED flashlight that last a very long time. Remember - Avoid all light as if it would harm you!

Eyepieces are available in different barrel sizes or formats. This "format" is a measurement of the diameter of the barrel size that drops into the telescopes focuser. There are 3 different sizes of eyepieces. 1.25 Inch - 2 Inch - and 0.965 Inch

The most common format of eyepieces is the 1-1/4 inch format. You could almost call this the "standard" for eyepiece size. Nearly all brands of telescopes use this common size.

Many telescopes have the option of using the larger 2 Inch format eyepieces. 2 Inch format eyepieces will give you much larger fields of view. Some telescopes have focusers that are ready for 2 Inch eyepieces and some will require a special diagonal to convert to the 2-inch format.

The last format is the 0.965 inch format. These eyepieces are common on inexpensive department store telescopes. If you have a telescope that will only accept the 0.965" format eyepieces you can purchase adapters that will convert the telescope to accept the more standard 1-1/4 inch format.

Eyepiece and Telescope brands do not need to match. If you have a telescope that is no longer manufactured and you are looking for replacement eyepieces, you do not need to purchase the same brand. You do however need to purchase the same format.

Computerized GO TO and GPS telescopes
Automatically Locate and Track Objects in the Sky

One of the most revolutionary enhancements of telescopes in recent years is the computerized auto-finding telescope. These telescopes have the ability to take the user directly to any object in the sky at the push of a button. Commonly known as GOTO telescopes, these instruments are changing how the backyard astronomer uses telescopes.

This article will talk about how GOTO telescopes work and how they do much more than just find objects.

Simple - But not that simple - A telescope that automatically moves and takes you to objects in the sky! As amazing as that sounds there is a bit of pre set-up work that needs to be done. It is not as simple as setting the telescope on the ground and pressing the "Saturn" button. The telescope first needs to be aligned.

In order for a GOTO telescope to accurately point to objects in the sky, it must first be aligned with two known positions (stars) in the sky. With this information the telescope can create a model of the sky, which it uses to locate any object with known coordinates. The most common way to align a GOTO telescope is the 2 Star Alignment. The GOTO telescope will ask the user to input simple information such as Date, Time and Location - This basic information will have the telescope roughly aligned. Now it will need to be fine-tuned. Based on the information you have provided the telescope it will automatically select a bright star that is above the horizon and start moving towards it. This movement of the telescope is known as slewing . At this point the telescope is only roughly aligned, so the alignment star should only be close to the field of view of the Finder Scope. Once finished moving, the display will ask you to use the hand controller to center the selected star in the view of the eyepiece. Centering the star in the eyepiece will now give the telescope an extremely accurate reference point.

After the first alignment star has been entered the telescope will automatically slew to a second alignment star and have you repeat the same procedure for that star. When the telescope has been aligned to both stars the display will tell you it is finished its alignment and you are now ready to find your first object!

If the wrong star was centered and aligned to, the telescope will display that the alignment was not completed successfully. If you are not sure if the correct star was centered, remember that the alignment stars will be the brightest stars nearest the field of view of the finderscope. There may be other fainter stars visible that are closer to the center of the finderscope, but the actual alignment star will be obviously brighter than any other star in the area.

The alignment procedure is far from difficult, but it does take some practice. The reward of having thousands of objects at the push of a button is simply amazing.

GOTO telescopes do something maybe more important than locating objects - they also track the object. Why is this important? The Earth is rotating on its axis and the telescope needs to also rotate in the opposite direction to counter the movement of the Earth. If you where to stand outside and point your arm up at the Moon and not move your arm, eventually you would not be pointing at the Moon anymore.

In a telescope, this speed is greatly amplified. Let's say, for example, you are viewing Saturn at a magnification of 40x - if you are not tracking, Saturn will only stay in the view of your eyepiece for a few seconds. Imagine if you are magnifying the same object at 100x magnification or more! The need to track an object is critical to enjoying observing anything from the moon to deep space galaxies. GOTO telescope will not only locate the object, but they will automatically track the object in the sky by turning in the opposite direction of the Earths rotation at the appropriate speed.

Many GOTO telescope also have GPS - Global Positioning System - features built right into the telescope. A GPS powered telescope will make the alignment procedure dramatically easier. There is no need to enter any date, time or location because the GPS will tell the telescope where it is on Earth within a matter of a few feet! When the telescope slews to the 2 alignment stars, they are very accurate. The telescope will still require you to fine tune the alignment by centering the alignment stars in the view of the eyepiece.

Got a beautiful view of the ocean or a patio overlooking the golf course? Many customers look to a Telescope to bring these views closer to home when a Spotting Scope may be the better choice.

If your objective is to use a magnifying device strictly for land use then a Spotting Scope may be the best choice. A Spotting Scope is essentially a telescope but it is designed for land-based observation. Most telescopes will come with more bells and whistles than is needed for simple land based observation. More importantly a telescope may not give you a correct image and may have upside down or inverted images and you will have to purchase an accessory to correct this. For more information see our article: Image Orientation - Why Is Everything Upside-Down?

A Spotting Scope will usually be much more portable than a large telescope and will be easier to use for land based observing. Many Spotting Scopes feature a zoom eyepiece or will accept standard telescope eyepieces.

So does this mean a Spotting Scope is not going to work for astronomy? Not the case. A Spotting Scope will be primarily for land observation but will also be excellent for simple Moon and Star watching. If you are looking to examine the Moons of Jupiter than a Spotting Scope will not be for you. A telescope would be the better option.

To decide between a Spotting Scope and a Telescope you want to first decide what you want to use it for. If you were thinking something like 80% land observation and 20% moon and stars - a Spotting Scope would be the better choice. If it is the opposite than an appropriate telescope will be the better option.

Looks do matter.

When choosing a Spotting Scope or Telescope for your home or patio it is important to get one that is attractive looking to you. If this is a piece that will always be set-up - don't let it be an eyesore. Spotting Scope and telescopes will come in different sizes and colors. Be sure to choose something you will be happy to look at as well as through.

Observing Our Closest Star
The Sun

The Sun, our closest star is about 93,000,000 miles away from Earth. It is so far away that light traveling at a speed of 186,000 miles per second, will take about 8 minutes to reach us. Why about 93 million miles away? The Earth does not travel around the sun in a perfect circle. Our orbit around the Sun is elliptical. This means that the distance between Earth and the sun changes during a year. Around January 2 nd the sun is 91.4 million miles away and around July 2 nd it is 94.8 million miles away. Give or take a few inches!

Observe The Sun Safely - Never look at the Sun without a filter!

To observe the sun with your telescope you will need an appropriate solar filter fitted for your telescope. Most telescopes have the option of purchasing a matching solar filter special designed to fit the telescope. With a solar filter you can see detail in sunspots, bright faculae near the limb and the mottled areas known as granules with these filters. The Sun offers constant changes and will keep your observing interesting and fun. Even small aperture telescopes can enjoy features of the Sun.

We strongly recommend only using a solar filter that covers the objective of the telescope. These are called Full Aperture Solar Filters. Some telescopes come with a "Solar Filter" that screws into the eyepiece. These filters are very unsafe and should be avoided.

Don't Forget about the Finderscope!

Locating the sun with a Solar Filter can be difficult. Never use the finderscope to locate the sun. It is best to remove or cover the finderscope so you will have no accidents. A neighbor or friend walking by may not understand the care needed to observe the sun and may peek into the wrong scope!

Locate the sun first by moving the telescope to the general area of the sun by hand. Then watch the shadow that the telescope itself gives off on the ground. When the shadow is shortest, you will be very close to the sun. It is also a good idea to use a very low powered eyepiece to first observe. This will give you the largest field of view and make locating the sun much easier.

If you take anything away from this article, it is that you need to be careful. This should not scare you away from the enjoyment of observing the sun, as long as you have the appropriate filter and always think safety, observing the sun will give your telescope 24-hours a day of enjoyment!

You just got your new telescope - you carefully opened the box and followed all the instructions. That sun just will not go down fast enough. Finally, darkness falls. The first thing a new telescope owner will do is point it up at the Moon and look into the eyepiece. Wow.

But if you can imagine, the Moon actually can appear better than that when properly filtered. telescopes have the ability to attach filters for many different purposes - some of the most common filters are for looking at the Moon, Planets and Sun.

Eyepiece filters are an invaluable aid in lunar and planetary observing. They reduce glare and light scattering, increase contrast through selective filtration, increase definition and resolution, reduce irradiation and lessen eye fatigue.

Moon Filters

A Moon Filter will thread directly onto the bottom of your eyepiece. Nearly all eyepieces are threaded for filters. Think of a Moon Filter like sunglasses for your telescope. Moon Filters will cut down glare and bring out much more surface detail and give you better contrast.

Planetary Filters

Astronomical filters work by blocking out certain colors in the visible spectrum of light. A red filter, for example, will block out all but the red wavelength of light. If you look at an object that is primarily red while using a red filter, the object will appear very bright. Areas which are not red will appear more clearly because they contrast with the wavelength of light which is being passed by the filter.

When using filters, make note of the visible light transmission (VLT) of the filter you would like to use. The VLT is a number, which describes the overall amount of light that is allowed to pass through the filter. The lower the VLT number, the dimmer an image will appear. Filters with a VLT less than 40% are not recommended for use on telescopes with an objective aperture of less than 6 inches due to the decreased image brightness.

Filters are sorted by the Kodak Wratten numbering system. Each filter is listed by its color and Wratten number. The Wratten numbers will help to ensure similar results between different filters. The image should appear the same when viewed through any #82A Light Blue Filter, for example.

Here is a list of some of the most commonly used astronomical color filters and some suggested uses for each of them.

#8 Light Yellow - 83% VLT

A light yellow filter helps to increase the detail in the maria on Mars, enhance detail in the belts on Jupiter, increase resolution of detail in large telescope when viewing Neptune and Uranus, and enhance detail on the moon in smaller scopes

#11 Yellow Green - 78% VLT

Yellow-Green helps to bring out dark surface detail on Jupiter and Saturn, darkens the maria on Mars, and improves visual detail when viewing Neptune and Uranus through large telescopes.

#12 Yellow - 74% VLT

Yellow filters help greatly in viewing Mars by bringing out the polar ice caps, enhancing blue clouds in the atmosphere, increasing contrast, and brightening desert regions. Yellow also enhances red and orange features on Jupiter and Saturn and darkens the blue festoons near Jupiter's equator.

#21 Orange - 46% VLT

An orange filter helps increase contrast between light and dark areas, penetrates clouds, and assists in detecting dust storms on Mars. Orange also helps to bring out the Great Red Spot and sharpen contrast on Jupiter.

#23A Light Red - 25% VLT

Light red filters help to make Mercury and Venus stand out from the blue sky when viewed during the day. Used in large telescopes, light red sharpens boundaries and increases contrast on Mars, sharpens belt contrast on Jupiter, and brings out surface detail on Saturn.

#25A Red - 14% VLT

Red provides maximum contrast of surface features and enhances surface detail, polar ice caps, and dust clouds on Mars. Red also reduces light glare when looking at Venus. In large telescopes, a red filter sharply defines differences between clouds and surface features on Jupiter and adds definition to polar caps and maria on Mars.

#38A Dark Blue - 17% VLT

Dark blue provides detail in atmospheric clouds, brings out surface phenomena, and darkens red areas when viewing Mars. Dark blue also increases contrast on Venus, Saturn, and Jupiter in large scopes.

#47 Violet - 3% VLT

Violet is recommended only for use on large telescopes. A violet filter enhances lunar detail, provides contrast in Saturn's rings, darkens Jupiter's belts reduces glare on Venus, and brings out the polar ice caps on Mars.

#56 Light Green - 53% VLT

Light Green enhances frost patches, surface fogs, and polar projections on Mars, the ring system on Saturn, belts on Jupiter and works as a great general-purpose filter when viewing the Moon.

#58 Green - 24% VLT

Dark green increases contrast on lighter parts of Jupiter's surface, Venutian atmospheric features, and polar ice caps on Mars. Dark green will also help bring out the cloud belts and Polar Regions of Saturn.

#80A Blue - 30% VLT

A Blue filter provides detail in atmospheric clouds on Mars, increases contrast on the moon, brings out detail in belts and polar features on Saturn, enhances contrast on Jupiter's bright areas and cloud boundaries. A blue filter is also useful in helping to split the binary star Antares when at maximum separation.

#82A Light Blue - 73% VLT

Light blue functions much the same as #80A Blue while maintaining overall image brightness. Light blue will also help to increase structure detail when looking at galaxies.

Other kinds of filters

Light Pollution Reduction Filters (LPR) are designed to selectively reduce the transmission of certain wavelengths of light, specifically those produced by artificial light. This includes mercury and both high and low pressure sodium vapor lights. In addition, they block unwanted natural light caused by neutral oxygen emission in our atmosphere. As a result, LPR filters darken the background sky, making deep-sky observation and photography of nebulae, star clusters and galaxies possible from urban areas. LPR filters and not sued for lunar, planetary or terrestrial photography.

For more information on Solar Filters for observing the Sun. Please see our article, Observing Our Closest Star - The Sun

Not interested in the complexities of a telescope? A good pair of binoculars can bring the heavens closer in a much easier to use package. Binoculars give you the advantage of using both eyes for a more three dimensional stereo view. Binoculars can be very good for observing the moon and stars. The Orion Nebula and Andromeda Galaxy are easy to spot on a dark clear night. Even Jupiter and its Moons are visible through a pair of binoculars.

When choosing a binocular for astronomy you first need to understand how binoculars work. Similar to telescopes, a binocular needs to gather light. The same critical feature for telescopes is the same in binoculars - you need a large enough objective lens to gather light.

Binoculars are measured with two key features - its magnification and its objective lens. For example, a binocular may be listed as 10x50. The first number 10 is the magnification of the binocular. The second is the size of the objective or outside lens in millimeters. 10 times the naked eye with a 50mm objective.

Like telescopes, objective is the most important factor. It's the same for binoculars for astronomy. We recommend a minimum of a 50mm objective lens for astronomy. A 7x50 or 10x50 are very common choices for astronomy. They offer a large enough objective lens and a magnification that is enough to bring objects close enough to observe.

Even better for astronomy is the larger objective lens binoculars. Many astronomy binoculars will features objective lenses between 60mm to 100mm or even more. These larger binoculars will usually require a tripod, as they are very heavy. The larger objective size binoculars will often have much more magnification than traditional sized binoculars. Powers of 10x, 15x, 20x or more are common on larger astronomy binoculars. When you have binoculars of this size and magnification - having a steady hand is usually not enough. Having them mounted on a tripod will give you the best results. Many giant binoculars will have a built-in tripod mount or have an adapter included or sold separately.

One of the greatest advancements in binoculars is the Image Stabilized binocular. Brands such as Canon and Nikon have developed a revolutionary method of stabilizing the image with a tiny microprocessor inside to counter the movement of your hands. These binoculars are amazing for astronomy as you can have all the advantages of high power magnification without the need of a tripod.

Astronomy is a fascinating lifetime hobby enjoyed by young children to centenarians, by people from all walks of life and with varied interests.

You can observe or photograph the heavens on a casual or serious basis, undertake scientific study or marvel at the wonderment of our existence. Astronomy can be a fun and relaxing way to soothe our minds and bodies from our hectic everyday life. It is a way to enjoy nature, being outside and marveling at the night sky.

So what can you expect to see?

Prepare for an awesome spectacle. The moon's disk has a pastel-cream and gray background, streamers of material from impact craters stretch halfway across the lunar surface, river-like rilles wind for hundreds of miles, numerous mountain ranges and craters are available for inspection. At low or high power the moon is continually changing as it goes through its phases. Occasionally you will be treated to a lunar eclipse.

It is quite safe to view the Sun if you utilize a proper solar filter. The Sun is fascinating to inspect as you detect and watch the ever-changing sunspot activity. If you are fortunate enough, and are willing to travel to remote locations, you may at some point experience a solar eclipse. For more information see our article - Observing The Sun

Observation of planets will keep you very busy. You can see Jupiter with its great red spot change hourly, study the cloud bands and watch its moons shuttle back and forth. Study Saturn and its splendid ring structure, watch Venus and Mercury as they go through their moon-like phases. Observe Mars and see its polar cap changes or watch the dust storms and deserts bloom with life. Uranus, Neptune and Pluto can be seen easily with 8" or larger telescopes.

There are two types of star clusters- (1) open star clusters (also called galactic clusters) which are loosely arranged groups of stars, occasionally not too distinctive from the background stars, and (2) globular star clusters which are tightly packed groups of many millions of stars.

These are glowing clouds of gas falling into two types- (1) planetary nebulae which are relatively small ball-shaped clouds of expanding gases and are believed to be the remnants of stellar explosions, and (2) diffuse nebulae which are vast, irregularly-shaped clouds of gas and dust

Galaxies

These are vast, remote "island universes," each composed of many billions of stars. Galaxies exist in a variety of sizes with regular and irregular shapes.

Comets

Magnificent comets are routinely visible through telescopes .

These are pairs of stars orbiting around a common center of gravity, often of different and contrasting colors.

What you can see is dependent on a lot of factors. The most important of these for astronomy is aperture. The ability for a telescope to gather light is critical. Other important factors are optical quality, steadiness of your tripod and mount, seeing conditions, your location (city or rural), brightness of the object and your experience.

Astrophotography can be a fun and rewarding hobby. Even a novice telescope user can take beautiful images of the moon and stars. There are many types of astrophotography from simple piggyback photography - by mounting your camera on top of your telescopes optical tube to fully connecting your telescope to a 35mm or Digital camera.

One of the simplest methods of astrophotography is to attach your camera directly to the top of your optical tube. This will allow the mount and its motor drive to also move the camera. Most telescopes have the ability to purchase a piggy back bracket to let the camera go for a ride.

A more advanced way to take astronomical images is directly through the telescope connected to a camera. To attach a camera to a your telescope you will require 2 simple parts. A T-Adapter and a proper T-Ring for your camera brand. The T-Adapter will connect to your telescope. A T-Ring specific to your camera will attach to your camera. The now the telescope and the camera are ready to be connected. With this simple connection you can take amazing images or the moon and planets and with practice, you can take stunning images of deep space objects such as Galaxies and Nebulae.

Connecting the modern Digital cameras to telescopes is still pretty new. Most digital cameras do not have threaded lenses and require very specific attachments specific to the camera itself. The company ScopeTronix is a brand that we offer that has developed a connection for hundreds of digital cameras. Odds are if you have a digital camera - we have a connection that can make it fit.

Unfortunately the answer to this question is no. Not even the most powerful telescopes ever made are able to see these objects. The flag on the moon is 125cm (4 feet) long. You would require a telescope around 200 meters in diameter to see it. The largest telescope now is the Keck Telescope in Hawaii at 10meters in diameter. Even the Hubble Space telescope is only 2.4 meters in diameter. Resolving the lunar rover, which is 3.1 meters in length, would require a telescope 75 meters in diameter. So our backyard 6 inch and 8 inch telescopes are not even going to come close!

Obviously there is no "wind" for the flag to fly in. Getting a flag to "fly" on the moon was actually started as a top-secret project mandated by Congress in the spring of 1969. Flying a flag on the moon was a complicated issue. First NASA officials had to get passed a United Nations treaty that bans the national appropriation of outer space or any celestial bodies. The United States would not and could not claim the moon as US territory. Raising a flag on the moon could be taken the wrong way in the eyes of the rest of the world. The raising of the flag would be a symbol of our nations goal that began with President John F Kennedy's pledge to Congress on May 26 th 1961:

"I believe this nation should commit itself to achieving the goal before this decade is out, of landing a man on the moon and returning him safely to the earth. No single space project in this period will be more impressive to mankind, or more important for the long range exploration of space, and none will be so difficult or expensive to accomplish."

There was also the issue of where to put the flag on the lunar module to protect it from the elements. A gentleman named Tom Moser, a young design engineer at Johnson Space Center, was given the task. Moser developed a collapsible flagpole with a telescoping horizontal rod sewn into a seam on the top of the flag to extend it outward. The flag was brought to the moon in a heat resistant tube attached to the ladder of the lunar module. The flag is rumored to have been purchased at Sears but is not confirmed.

Neil Armstrong and Buzz Aldrin recalled what happened when they tried to set up the flag: "It took both of us to set it up and it was nearly a public relations disaster, " he wrote, " a small telescoping arm was attached to the flagpole to keep the flag extended and perpendicular. As hard as we tried, the telescope wouldn't fully extend. Thus the flag which should have been flat had its own permanent wave"

The answer to this question is not known. It is uncertain if the flag remained standing or was blown over the by engine blast when the ascent module took off to return the crew back to Earth. The lunar surface was barely holding the flag upright enough to begin with, it is unlikely that the flag is still upright.