Buying their first telescope, an optical time machine to explore the universe, amateur astronomers have different goals. Some aspire to discover comets or someday publish astro photography, others just want to enjoy views of the moon and planets from time to time. Whatever your goals, one thing is for sure: start with the basics by learning how to use your telescope.
What is this?
A telescope is a device designed to observe distant objects. The term usually refers to optical instruments, but telescopes exist for most of the electromagnetic spectrum and for other types of signals. An optical telescope magnifies the apparent size of distant objects.
Telescopes work by using one or more curved optical elements - lenses or mirrors - to collect light or other electromagnetic radiation and focus that light or radiation there,where the image can be observed, photographed or studied.
The device is assembled in accordance with the instructions for the telescope purchased by the user. But there are some tips that can make this job easier:
- Assemble the telescope in a room where there is a lot of light.
- Have enough space and patience and all the tools required for assembly before starting.
- After assembly is complete, take some time to learn a little about how to use the telescope and its functions before taking it outside for the first time.
What is it made of?
Let's study the structure of the telescope:
- The optical tube is the part that most people think of as a telescope. It has a lens at the front (refractor) or a mirror at the back (reflector) that is used to collect light. Some optical tubes have both lenses and mirrors. These are the so-called catadioptric telescopes. The most common are the Schmidt-Cassegrain (SCT) and Maksutov-Cassegrain (MCT) telescopes.
- The mount (mount) is what holds the optical tube. It comes in several types: equatorial, alt-azimuth, computerized GoTo or manual. The Alt-Azimuth mount allows you to move the telescope in straight lines - up, down, right and left. The equatorial mount was designed to track stars as they arc across the sky. It can be adjusted tocompensate for location by latitude. Equatorial mounts can be very simple or have a wide range of features and components, from simple motors on one or both axles to a complete computerized system that can operate with the observatory's telescopes.
- The eyepiece is the part of the telescope system that actually provides magnification. The optical tube collects light and the eyepiece magnifies the image. Most starter kits will include one to three eyepieces, each providing a different level of magnification. The higher the number on the eyepiece, the lower the magnification. So a 25mm eyepiece will provide less power or less magnification than a 10mm eyepiece.
- A Barlow lens is a device that goes between the eyepiece and the focuser. It multiplies the magnification of the eyepiece by a specified amount, usually a factor of 2 or 3. The advantage of this lens is that it gives you more magnification with fewer eyepieces.
- Diagonal. SKT and MST refractors usually have diagonals. No more kneeling down to look through a telescope that points to the stars - the diagonal bends the light into a more comfortable viewing position. The main thing to know is that the 90 degree diagonal, also called the star diagonal, is optimized for astronomy. The 45 degree diagonals are optimized for daytime use as observation areas, not for astronomy.
- The focuser is a moving device thatused to focus the image.
- The Red Dot Finder (RDF) is a targeting tool, like a scope on a weapon. It is used to point the telescope at the target.
How the telescope moves
You should practice moving your telescope in the comfort of a well-lit home. Regardless of the type of attachment, positional adjustments are made in the same way.
In the case of non-computerized telescope mounts:
- Start by loosening the lock knobs at altitude and azimuth (for alt-azimuth mounts) or on the forward lift and tilt axes (for equatorial mounts).
- Grip the optical tube, push or pull it in the desired direction.
- Lock the telescope so it doesn't move by itself.
This method is used for large, wide movements across the sky. For more incremental movements, manual fasteners should have one or two cables or "slow control" handles.
In the case of a computerized telescope mount Go To:
- Use the supplied hand controller to move the telescope.
- Select the slew rate depending on how far you want to move the telescope across the sky. Higher speeds are used to move from one object to another, while slower speeds are used to center the object or keep it in the eyepiece. Take some time to experience these speedsexperiment with the direction buttons on the hand controller and learn how to use this type of telescope.
Alignment and use of the finder
Now you should understand how to properly adjust the telescope and viewfinder.
Finders are an important accessory because without them the user will spend most of their time trying to find objects instead of looking at them.
Normally a telescope has one of two types of finder scope: red dot finder or optical finder:
- The optical viewfinder is a small device that is held on top of the main telescope with the viewfinder bracket. It offers a view of the sky at low magnification, typically anywhere from 6X to 10X, and a crosshair is visible through the eyepiece to help center the subject in the finder's field of view.
- The red dot finder displays a wide field of sky at zero magnification. Instead of looking through the eyepiece, the user looks at a glass or plastic screen that reflects a red dot. Such a finderscope is usually attached to the telescope using a raised bracket.
Both types of telescope finders work well, but they must be aligned with the telescope or they will be useless.
- Install the finder arm and the finder itself on the telescope as indicated in the instruction manual.
- Select the eyepiece with the lowest magnification and place it in the focuser.
- Withintake the telescope outside and place it in a place where you can see a stationary object that is at a great distance. Stop sign, lamp post, or high voltage insulator on an electrical pole.
- Manually aim the telescope as accurately as possible at the target, and then look through the eyepiece. The object should be in the field of view, but if it is not, use the slow motion controls or the dial on the telescope mount to adjust until the target is in the center of the eyepiece.
- Tighten the clamps on the telescope so that it does not move.
- Now when looking through the finder, use the adjusting knobs on the viewfinder or finder arm to center the target in the finder's field of view as accurately as possible.
- When the telescope is locked, carefully change the eyepiece to the next highest magnification.
- When the target is in the center of the viewfinder and eyepiece at the maximum magnification available, the viewfinder is level.
How to use a refractor telescope
Such telescopes use glass lenses in a metal tube to collect light from distant objects such as the moon, planets, star clusters and nebulae. When used in conjunction with interchangeable magnifying eyepieces, the refractor allows these astronomical objects to be studied in extraordinary detail. An example of this type of device is the Sky-Watcher BK 705AZ2 telescope:
- Select an observation site away from light sources.
- Place the tripod on the ground. Extend each tripod leg to the same length, and then tighten the screws on each leg to secure it in place. Place the tripod vertically. Loosen the thumbscrews on the tripod mount bracket. Insert the telescope into the tripod mount bracket, and then tighten the fixing screws.
- Loosen the telescopic screw. Insert the viewfinder area into the mount and tighten the fixing screw.
- Point the telescope at an astronomical target. Choose a bright object such as the moon or star. Raise or lower the tube and move it from side to side to point the telescope in the direction of the target.
- View in the search field. Adjust telescope orientation to center object in viewfinder area.
- Insert a low power eyepiece - one with a magnification of 75X or less - into the focuser of the telescope.
- Tighten the fixing screw to secure it in place. Look through the eyepiece and make sure the object is in the field of view. If not, look at the search area and re-center the object. Adjust the focus knob until the subject is sharp in the eyepiece.
- Insert a high power eyepiece into the telescope's focuser to examine the object in more detail.
- Adjust the focuser to sharpen the object in the eyepiece.
How to use a reflecting telescope
Galaxy viewing methods with this device allow you to study objects from the most elementary to the extremely complex.Once the user has successfully mastered the control of the random survey unit, the transition to a more accurate and complex view should be relatively easy. An example of this type of device would be the Celestron AstroMaster 76 EQ:
- Read the user manual of the device.
- Determine the eyepiece mount and practice changing and removing different eyepieces. Each telescope manufacturer uses different types of eyepiece locks.
- Find a finder scope to be used to set up the telescope just before using it. Pay attention to the location of the screws that should surround the viewfinder area. These are the screws that will need to be used for alignment.
- Study star charts.
- Find a dark open clearing where the moon is visible to adjust the telescope.
- Install the telescope, point it at the sky and remove the lens cap.
- Place the lowest magnification eyepiece in the holder and rotate the telescope until the moon appears. Make small adjustments to the position of the telescope until the moon is in the center of the field of view.
- View in the search field. If necessary, adjust the screws surrounding the viewfinder area until the moon is perfectly centered on the crosshairs in the center of the area.
Now you can explore space by referring to star charts as needed.