Last Update:  10-29-2006

Sources:  Partial information gleaned from the book Star Ware by Phillip S. Harrington

Also see CCAS Astronomical Terminology

Catching the Bug
Becoming involved in astronomy can be as easy as getting a book on the constellations (a good one is The Stars by H. A. Rey, published by Houghton Mifflin), a planisphere (a simple, rotating wheel map of the sky for a year), a good pair of binoculars, a comfortable chaise lounge (or better yet, laying on a soft pad on the grass) and clear skies.  You can then spend months studying the constellations and their stars.  From there the "sky is the limit".  You will then feel the need for a simple telescope for around $300 to $500 (you can get a nice entry-level scope for this price), a set of star charts (a good one is the deluxe, spiral bound Sky Atlas 2000 by Wil Tirion and Roger Sinnott, published by Sky Publishing Corp. and Cambridge University Press) and then study the sky more seriously.  Then the time comes when you really become hooked and decide to make the next big step into a fine piece of telescopic optical equipment for several thousand dollars.  Now, much to the amazement of your family and friends, you find yourself outside in the chilly dark of night wearing wool clothing over every inch of your body except your eyeballs until 2 or 3 AM, ooing and aahhing at the many hidden objects that the star charts say are there but you can't see with your naked eye.  Sure enough those Messier and NGC objects are indeed in the sky for your viewing pleasure ... you are now finally discovering the gems of the cosmos ... galaxies, globular clusters and nebulae.  Add to this your discovery of the vastness of space and astronomy information and beautiful photo images on the web.  Welcome to the world of amateur astronomy.

Websites for Beginning Stargazers
Sky & Telescope: Stargazing Basics
SpaceRef's Telescopes 101 guides to selecting and using telescopes
Orion Telescopes:  Learning Center   select "Learning Center" in the top menu
Star-Hopping to the Oldies   Bill Ferris
Advice for Beginners   The Astronomy Connection
Getting Into Astronomy  San Jose Astronomical Association
Information for Beginning Astronomers   San Jose Astronomical Association
Getting Started in Astronomy   Astronomy Boy
Nick Strobel's Astronomy Notes    an EXCELLENT website! 
   > Introduction to Astronomy  size, time, scientific models, astrology
   > Astronomy without a Telescope  celestial sphere, coordinates, time, seasons, planetary motions
Deep Sky Tours   Bill Ferris   sky watching organized by season  
Getting Started in Astronomy  Keith's Astrophotography and Astronomy Site
Beginning Astronomy  Peoria Astronomical Society
Beginning Astronomy  ThinkQuest
Understanding and Buying Binoculars   Optics Planet

Astronomy Magazines
Astronomy Magazine   excellent for the beginning and intermediate astronomers
Sky & Telescope Magazine   excellent for more serious astronomers
Night Sky Magazine   by Sky & Telescope Magazine    excellent for beginning astronomers
If you become a CCAS member, you can obtain reduced subscription rates to Astronomy Magazine and Sky & Telescope.

Stargazing Checklist
Be sure to plan in advance and gather everything together before heading out for a night of stargazing, especially if you are driving to some distant viewing site.  Here is list of items to consider:

Important:  Please protect our environment and telescope viewing sites.  NO littering, only leaving footprints.

Telescope Types
There are three basic types of telescopes in use by amateur astronomers as listed immediately below.
Also check out Sky & Telescope's Guide to Choosing a Telescope.

Refractor - uses a large objective lens mounted at the front of the telescope tube.  The astronomer looks straight through the telescope tube from the eyepiece to the objective lens.   A refractor is the typical, classic telescope.  Good quality refractor telescopes are very expensive because of the high quality optical elements (lenses) that are required.  Refractors are generally applicable to very serious and experience astronomers, being heavily used for astrophotography.  For images of typical refractor telescopes, go to Google, select Images, then enter refractor telescope.  Also see this diagram.

Reflector - uses a large primary mirror at the base of the telescope tube.  The astronomer looks through the eyepiece on the side of the telescope tube near the front objective-end of the scope.  His/her vision is reflected by a small secondary mirror at the front-end of the tube, back down to the primary mirror at the base of the tube.  For images of typical refractor telescopes, go to Google, select Images, then enter reflector telescope.  Also see this diagram.  A very popular style of reflector telescope is a Dobsonian telescope ranging from 6" diameter to 12" diameter.

Catadioptric - uses a lens (called a corrector plate) at the front-end of the telescope tube with a large primary mirror at the bottom of the tube.  A commonly used catadioptric telescope is known as a Schmidt-Cassegrain telescope.  The astronomer looks straight into the bottom-end of the telescope with his/her vision being reflected off a small secondary mirror in the "corrector plate" at the front-end of the tube back down to the primary mirror at the base of the tube near the eyepiece.  Also see this diagram.

Terminology
Aperture:  When we speak of a telescope's size, we speak of its aperture.  This is the diameter (in inches, centimeters or millimeters) of the telescope's prime optic.  For a refractor, the objective lens diameter is used.  Reflector and Catadioptric telescopes use their primary mirror as the aperture size.  In general, the larger the aperture, the brighter and clearer are the objects.  The larger the diameter, the greater the amount of light that your eye gets to see, so the objects are clearer and brighter.

Focal Length:  This is the distance (in inches, centimeters or millimeters) from the objective lens (at the front-end of the telescope) or the primary mirror (at the base of the telescope) to the focal point (or prime focus) where the rays of light converge (where the eyepiece is located).

Focal Ratio:  Otherwise called the " f " number, is the focal length divided by the aperture.

Magnification:  Word to the wise - It is incorrect to believe that the higher a telescope's magnification the better the telescope.  Don't be fooled by a telescope having a high magnification as being a superior telescope.  The higher the magnification, the fainter and fuzzier celestial objects can become.  The numbers on an eyepiece (in millimeters) such as 7mm, 12mm or 26mm, are the focal length of  that specific eyepiece.  A telescope's magnification is the telescope's focal length divided by the eyepiece focal length.  Be sure both figures are in the same units of measure, both either in inches or millimeters.  There are 25.4mm per inch.

Light-Gathering Ability:  The human eye is an exquisite optical device, but it has its limitations, more so as we get older.  In general, under the darkest of conditions the pupil of a human eye expands to about 7mm in diameter.  As we get older, the dilation (expansion) of our pupil reduces in diameter.  In general, the beam of light that exits the telescope eyepiece should NOT be larger in diameter than that of the astronomer's eye pupil or else the eye is not seeing everything possible.  The larger the telescope primary objective lens (refractor telescope) or primary mirror (reflector telescope), the more light gathering is provided for our eyesight.

Purchasing a Telescope
In a nutshell, if you are at all serious about your interest in astronomy, DON'T purchase telescopes or any astronomical equipment from a department store, discount store, hobby shop or TV buying channels.  Their equipment may look and sound exciting and enticing, especially at the low price of several hundred dollars, but you will receive inferior equipment, PERIOD!  Purchase telescopes only through reputable astronomical equipment suppliers and camera shops having higher-end equipment.  Celestron, Meade and TeleVue are very popular manufacturers who do well with their equipment, but there are also other manufacturers who do nicely, and some manufacturers who make extremely fine and expensive equipment (such as Astro-Physics and Takahashi).

One good on-line source for good quality astronomical equipment is Orion Telescopes.  They are very popular.  You can also order hard-copy catalogs.

For a list of some serious manufacturers and dealers, see CCAS Useful Links - Hardware & Accessories.  For the average occasional home amateur astronomer, the Dobsonian style Alt-Az (Altitude-Azimuth) and Newtonian reflector telescopes are popular and very user-friendly, rugged and very reasonable in cost.  Many of the large-scale telescope manufacturers and dealers offer Dobsonian telescopes, such as Celestron, Meade, Starsplitter Telescopes, and Orion Telescopes.  Another style that is also very popular is the Equatorial Mount Newtonian style telescope, such as those offered by Celestron and Meade.  In any case, expect to spend in the range of $500 to $1,000 on a good, serious, first-time telescope (including an eyepiece or two), one that will have good resale value in the event you later decide to upgrade your telescope or just get out of the astronomy business.  Such a quality telescope will last for many lifetimes if properly cared for.  Be sure to see the next section on Eyepieces.

Telescope Selection: 

For detailed information on vision and optics, try HyperPhysics, and select Light and Vision.

Telescope Basics Websites
Sky & Telescope: Choosing Equipment
Astronomy Magazine  scroll down the left navigation menu to Buying a Telescope
So You Want To Buy a Telescope - Advice for Beginners   Ed Ting
The Newtonian Pages
How to Buy Your Own Eye to the Sky   SPACE.com
Telescopes   Nick Strobel's Astronomy Notes   an excellent overview of telescope types & operation
Telescope Buying Guide   Eagle Optics
Telescope Buyer's Guide  Prairie Astronomy Club
Telescope Reviews   Todd Gross
Telescope & Eyepiece Reviews   Ed Ting
How Telescopes and Binoculars Work  TeleVue
Choosing Your Telescope's Magnification  TeleVue
Telescope Formulas  TeleVue
Cleaning Eyepiece and Telescope Optics  TeleVue
A Guide to Telescopes   Dan's Camera City
How to Choose the Right Telescope  Optics Planet

Selected Telescope Manufacturers and Dealers
CCAS Useful Links - Hardware & Accessories
Anacortes Telescope & Wild Bird     scopes, mounts, eyepieces
Celestron Telescopes   refractors, reflectors, Schmidt-Cassegrain
Meade Telescopes   refractors, reflectors, Schmidt-Cassegrain
Oceanside Photo & Telescope 
Orion Telescopes   all things astronomical, a storehouse of great astro stuff
Starsplitter Telescopes   Dobsonian scopes
Telescopes.com  

Support Resources
CCAS Useful Links - Books, Magazines, Posters, Products
Astronomy Software   Sky & Telescope

Overview
Even though the telescope itself is the major portion of the astronomical equipment, it is the eyepiece that make or breaks a telescope's capabilities.  Eyepieces are not cheap and should not be purchased a real cheap prices.  They should be treated with the utmost care and handling, just like a precision camera lens.  The primary components of an eyepiece are the eye lens nearest the eye and the field lens which is farthest from the observer's eye.  Most serious amateur telescopes use two basic sizes, or diameter, of 1.25-inch and 2-inch.  Magnification is a key term when speaking of a telescope and eyepiece.  In general, for celestial targets such as star clusters and nebulae, lower power is called for.  For good views of planets or smaller deep-sky objects (like planetary nebulae and small galaxies), higher power is called for.  An eyepiece must be determined for a specific telescope as one eyepiece will work well on some scopes and not on others due to the particular design of the telescope.  Another important factor in eyepiece selection is the size of the eyepiece exit pupil.  It must be very close to just a little smaller than the dilated eye pupil size of the astronomer (which is generally around 7mm or smaller).  If the eyepiece exit pupil size is too large or too small, the resulting image of a celestial object may be unsatisfactory.  When in doubt about eyepiece selection, check with a manufacturer or an experienced astronomer.

Eyepiece and Optics Websites
Astronomical Telescope Eyepieces: A Discussion for the Beginner   Jay Reynolds Freeman
Choosing Your Telescope's Magnification   TeleVue
Selecting an Eyepiece   Don Ware
Eyepiece Calculator  Frank Nowling
Eyepiece Calculator  David Paul Green 
Reviews: Nagler Eyepieces   Todd Gross
Telescope & Eyepiece Reviews   Ed Ting
Telescope Mounts   Telescopes.com
Cleaning Eyepiece and Telescope Optics  TeleVue

Eyepiece Dealers
Anacortes Telescope & Wild Bird    scopes, mounts, eyepieces
Eagle Optics   Meade, Celestron, TeleVue
Orion Telescopes  all things astronomical, a storehouse of great astro stuff
Optics Planet

Overview
Given today's high-quality telescopes and eyepieces, filters are becoming an invaluable accessory to improve image quality.  The human eye has difficulty in dealing with certain viewing conditions and light wavelengths.  Viewing of celestial objects is improved with the appropriate filters.  There are filters for viewing our Moon, the Sun and different types of deep-space objects.  Many filters screw inside the field-end of an eyepiece.  Here are the primary filter types and factors dealing with filters:

Light-Pollution Reduction (LPR) Filters - these filters are designed to block certain undesirable wavelengths of light.  They are also commonly referred to as Nebula Filters.  They come in three types:
  broadband filters
    pass a wide range of the visible spectrum, wavelengths from about 430nm to 550nm.
  narrowband filters
    pass wavelengths of light from about 480nm to 520nm.
  line filters
    very narrow wavelength range allowing only one or two specific wavelengths.

Lunar and Planetary Filters - these color filters enhance the view of our Moon and of the planets.  For beginning astronomers, typical filters are Deep Yellow (No.15), Orange (No.21), Red (No.23), Green (No.58) and Blue (No.80A).

Solar Filters - These are EXTREMELY important for any astronomer who wants to view the Sun. When looking at the Sun, NEVER point the telescope at the Sun until the solar filter has been installed on the field-end of the telescope.  And NEVER look through a telescope, finder scope or binoculars without using a commercially designed solar filter.  The only solar filter to use is the style that fits on the front end of the telescope.  NEVER use the style that is designed to fit inside the field-end of the eyepiece.  If unfiltered sunlight is permitted to enter the telescope, it can severely damage the telescope and create a viewing danger for the astronomer.  Using a properly designed filter on the front of the telescope prevents the extremely intense unfiltered sunlight from entering the telescope.  There are also very expensive specialty solar filters that block all of the light from the Sun except for a narrow band of light that allows the observer to view solar prominences and flares.  Some popular manufacturers of high-quality solar filters are provided below.   Thousand Oaks Optical solar filters

Filter Styles - There are two basic styles of solar filters, those that are full-aperture (fully allowing light through the front of the telescope and off-axis which has a smaller circle of filter material that is off-center in the solid-black material filling the remaining portion of the filter frame.  For viewing the Sun, it is actually better to use the off-axis filters which cuts down the sunlight entering the telescope which can overpower the observer's view.

Filter Safety - Check your solar filter for any cracks or pinholes.  You must not risk using a damaged filter because if it seriously fails while you are using it, you can severely damage your eye.  Pinholes can be easily fixed by dabbing a tiny dot of flat paint or fingernail polish using a toothpick.  If their are cracks, etc., then the filter must be discarded.

Filter Websites
Available Light Pollution and Narrow Band Filters   Prairie Astronomy Club
Use of filters in Visual Astronomy   Astronomy for Everyone

Solar Filters
Thousand Oaks Solar Filters

Filter Manufacturers & Suppliers
Anacortes Telescope & Wild Bird     scopes, mounts, eyepieces
Analytical Scientific overview of Celestron eyepiece filters
Hutech Astronomical Products
Lumicon Eyepieces and Filters
Meade Eyepiece Filters:
     Meade Lunar and Planetary Filters 
     Meade Deep-space Filters  
Orion Telescopes 
Thousand Oaks Solar Filters

In order for a telescope to work as it was designed, the scope's optics must be precisely aligned.  Fine telescopes have adjustment mechanisms to insure that your scope's optical components (mirrors and lenses) are precisely and correctly adjusted so that your view through the scope is not distorted and fuzzy.  Without correct optical alignment, your viewing will be compromised and will be very discouraging.  Once your telescope's optics are in proper alignment, take great care not to disturb your telescope.  Treat it very carefully and never jar your telescope.  Always insure your scope is stored safely in your home and when you are on the road to a viewing location.

Another very important factor in enjoyable viewing of the cosmos is insuring your telescope is properly aligned with the stars.  Most good telescopes have mechanisms and adjustments allowing you to train the telescope on a particular celestial object and have the scope manually or automatically follow that object, always keeping the object in the telescope's field of view.  Most fine telescopes have some type of electrically powered automatic mechanism to do this work for you called a motor-drive.  And some scopes have a manually operated mechanism having a knob you turn to easily move the scope to the current position of the object from the last viewing position in the past several minutes.  Keeping your telescope trained on the object with little or no work on your part is called "tracking".  In order for the tracking to work properly, during setup of the telescope for a stargazing session you will need to precisely align your scope with Polaris (the North Star).  Doing so will allow the telescope to track the object in direct synchronization with the Earth's rotation.

A few words of caution about tracking mechanisms, especially electrically powered automatic units ... treat them very, very carefully and never force the mechanism as there are many very fine gears that can easily be damaged by improper use.   Also, when using automatic tracking, be sure to periodically check to insure that you don't have any power cords wrapped around your telescope as eventually the automatic mechanism could wrap the cord tight, damaging your telescope's operation.  This is a definite concern for astronomers who set up long-exposure photographic sessions.

Polar Align Your Telescope, Here's How   Craig Hill
Polar Alignment   Astronomical League
Polar Alignment   Celestron
Polar Alignment   Tucson Amateur Astronomy Association
Polar Alignment   Telescopes.com
Polar Alignment in the Field  Astronomical League Astro Note 1
Polar Alignment using an Equatorial Mount   Lucian Kemble

A telescope does not work very well if the optical components are dirty.  The links below provide some insight into clearing your objective lens, mirrors and eyepieces.  Be sure you use the finest-quality optical cleaning tissues and solutions on your telescope's optics.  NEVER use Kleenex, normal tissue paper or toilet paper.  A common misjudgment by beginning astronomers is thinking that their optics must be squeaky clean all of the time.  This is not the case.  Optics should only occasionally be cleaned, once a year or so, if then, unless, of course, you have managed to get rain and dirt on your lenses, eyepieces and mirrors.  In general, you will notice a small buildup of fine dust on your lens or mirror.  This fine layer is of no concern and will cause little problem for your viewing.  Don't over-clean your optics and when you do clean them, go to great lengths to be very careful and soft in your work.  Please use many, many tissues in a cleaning job as they essentially cost nothing compared to replacing a lens or a mirror because you have scratched it from so many cleanings and using dirty tissues.   Also be sure to keep lens and eyepiece covers on your telescope at all times.  Watch out for clouds of dust from passing cars on dirt roads, covering your scope immediately.

How to Clean Optics on $500 or Less    Company Seven
Caring for Your Optics  Sky & Telescope
Cleaning Eyepiece and Telescope Optics  TeleVue
Cleaning Optics  Astro-Tom.com
Cleaning a Corrector Plate   Yasuyuki Kinoshita
Cleaning your SCT Corrector Plate   SCT website
Cleaning a Corrector Plate   Univ. of Phoenix   scroll down to Maintenance
Cleaning the Mirror of your Telescope 
Cleaning a Dirty Telescope Mirror  Delaware Valley Amateur Astronomers
Cleaning your Meade LX200   Meade

This is one of the most common pains-in-the-rear for astronomers.  It can easily catch you by surprise if you are not planning ahead.  You will need to be prepared to keep dew from forming on your telescope's optical components, fogging your view beyond use.  Once dew forms on the optics, it is time to close up shop or use an electric hair dryer to dry your components.  NEVER use your shirt sleeve, jacket, rags or cloth to keep wiping dew from your optics as there is dust in that dew that will slowly scratch the surfaces.  Some people use dew shields which are hoods that are placed on the field-end (front) of the telescope.  This works fairly well.  On refractor and Schmidt-Cassegrain (SCT) telescopes, some people use electric powered dew zappers which are placed around the telescope's front lens ring to keep the lens just warm enough to prevent dew from forming.  It is powered by a portable 12 Volt battery or directly from your automobile's battery.  Dobsonian and Newtonian scopes can also have powered dew zapping
components for their primary mirror.

A pointer about keeping dew from forming ... store your telescope in a cool, dry area in your home, possibly in your unheated garage, in a dust-free location (or case).  Insure that your telescope has a cover for the telescope tube and always keep dust covers in place.  Moving your telescope from inside a warm house or automobile to the cold outside quickly causes dew to form.  The key is to acclimate your telescope to the viewing conditions for at least several hours prior to viewing, keeping your lens cover in place until viewing time.  Having your telescope and eyepieces sit outside for at least an hour or two will greatly help reduce formation of dew.  Also get your dew zapper running about an hour prior to viewing so that it has time to warm the telescope's front end lens area (for refractors and SCTs).   Something to be aware of is that for many days following a rainy period, the ground can be saturated which can easily result in telescope dewing on what looks to be a wonderful night for viewing.

Dealing with Dew   Sky & Telescope
Dealing with Dew  Jeff Polston
Dealing with Dew  Stephen Tonkin
Kendrick Dew Remover
Insulated Dew Shield
Astrozap Dew Shields 
Celestron Dew Shields   Telescopes.com
Dew Shields and Dust Covers   B&H
Oceanside Photo & Telescope Dew Shields 
Homemade Dew Shield 
Homemade Dew Shield 
Dew Heaters  Astronomics
Dew Heaters  SmartAstronomy
Dew-Not Dew Removers  ScopeStuff 

Directories of Amateur Observatories & Piers
Amateur Astronomical Observatories   SEDS

Piers
Advanced Telescope System Piers
Anacortes Telescope Piers
Andrew Cooper & William Lofquist's Concrete Pier 
Arnet's Temporary Telescope Pier  Bill Arnet 
Building a Concrete Telescope Pier  photo gallery
Astro Pier   commercial site of semi-permanent mounting piers
Choi's Telescope Pier  Sunny Choi
Dan's Pier-Top Plates
Pier-Tech Telescope Piers
Smith's Permanent Telescope Pier  David Smith

Home Observatories
Sky & Telescope:  A Simple Backyard Observatory  
Bill Arnet's List of Amateur Observatories   SEDS
Bruce Johnston's Roll-off Roof Observatory
Steven Lee's Roll-off Roof Observatory
DARKlight Telescope Pier and Observatory
Fred Bruenjes' Moonglow Observatory 
Tom Smith's Roll-off Roof Observatory 
Glenn Elliott's Roll-off Roof Observatory 
Carsten Arnholm's Roll-off Roof Observatory 
All About Astro Roll-off Roof Observatory 

Your back will be very pleased if you have some form of seat to sit on while using your telescope.  It is also nice to have a comfortable seat to use around the viewing area.  Doing a lot of bending over to view the stars gets very old, very fast.  You can make your own chair from plans you can find in books and on the Internet (links below) or you can purchase commercial chairs costing upwards of $150 or more.  Try to have a seat that has a backrest as this is wonderful for a sore back after many hours of viewing.  Chairs designed for telescope use will have a number of adjustments to make the chair lower or higher.

Check out this article on observing chairs by Joel Frazer with Shenandoah Valley Stargazers.

Commercial Chairs
SCT - Observing Chairs  
CATSPERCH Observing Chair   a high-quality chair having a tall height setting
Camera Concepts Observing Chairs 
Cosmo Comfort Observing Chair   Telescopes.com
Kendrick Astro Instruments: Observing Chair  nice construction with with some limitations 
    also see Anacortes Telescope & Wild Bird for the Kendrick chair
Orion Telescopes  select Accessories / Observing Aids 
Starbound Observing Chair  Anacortes Telescope
Starbound Observing Chair  Company Seven
StarStep Observing Chair  from Starmaster Telescopes    interesting design

Home-Built Chairs
Denver Observer's Seat  nice little chair, but has some limitations
Shenandoah Valley Stargazers Observing Chair Construction 
Jim Crombie's Observing Chair 
Cloudy Nights Telescope Reviews - Walt's Observing Chairs  PDF file

At some point you (and possibly your family and friends) will start attending star parties having multiple scopes, astronomers and stargazers.  The most important rules to follow are to be extremely careful when moving around the very dark viewing area and do not use any white lights in the area (only red colored lights).  You can find more detailed information on star party etiquette at the CCAS Star Parties web page.

Bring your enthusiasm and a willingness to mingle in the darkness with astronomers and non-astronomers alike.  Move from scope to scope, taking care to first ask the telescope owner if you may take a peak and how to safely do so, asking as many questions as you wish and hopefully there will be an experienced astronomer in attendance.  But keep in mind that there are also many beginner astronomers like yourself.  We are all learning together.  It is a never ending job that astronomers love.