1. Telescope basics that are useful to know

   Some of the terms here are referred to in the following instructions.
   • There are two main components to your system - the mount and the telescope. The mount supports the telescope. The mount may sit on a tripod. The telescope, in most cases, is the big tube with a mirror at one end. This type of telescope is known as a reflector.
   • The telescope will usually come with two or more eyepieces and sometimes a Barlow lens. These are discussed later.
   • The telescope has some kind of spotter system. This may be a little telescope on the side of the main one, or it may be a device that projects a laser spot or ring (also on the side of the telescope tube). The spotter helps you find things with the telescope, but you need to align it first. This is discussed later.
   • Coordinates of celestial objects (things in the sky - stars, planets, etc.) are quoted in coordinates of right ascension (RA) and declination (Dec). These are similar to longitude and latitude on land.
   • Once you have an object in the eyepiece of your telescope, it won't stay there by itself unless you have a motor-driven equatorial mount or an electronic mount that will automatically track the stars. Remember how the Sun rises in the east and sets in the west? This is due to the spin of the Earth. The stars do the same thing at night and, without tracking, they will move out of the field of view of the eyepiece.
   • The best observing site is a dark site away from street lights or other artificial lighting. Your eyes become dark-adapted after about twenty minutes in dark conditions. You will see more detail at the eyepiece if your eyes are fully dark-adapted.
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2. Assorted tips

   • You will probably want to run through the whole setting-up process in the lounge room before you take the telescope outside at night. It's much easier to see how it all works with the lights on or in the daytime. It is also easier to align the spotter scope in the daytime. However, before you can align the spotter, you need to be able to set up the telescope on its mount. For this reason, aligning the spotter is discussed later.
   • If you do have it all set up in the lounge room and it is light-weight enough to carry it all outside fully assembled (telescope and mount/tripod) you can do so. The instructions below describe setting up the mount/tripod outside first and then installing the telescope on the mount. This is a better method for larger/heavier telescopes.
   • It's not a bad idea to lay out a light-coloured bedsheet on the ground under the telescope. That way if you drop screws, knobs, eyepieces, lens caps, anything at all, they won't be lost in the grass and are easier to see in the dark against the light background.
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3. Accessories

   • Have a small torch covered with red cellophane. The torch is for looking at bits of the telescope or mount, and for reading the planisphere. The red cellophane is used to preserve your dark-adaptation.
   • You will need a planisphere. The planisphere tells you which constellations are visible, which gives you a clue as to where to find interesting targets. It also names the bright stars which you may need for electronic alignment. You can use a commercial planisphere, but these are sometimes confusing. You can download a free one here which only shows the brighter stars.
   • You will want to know which targets are worth looking at with your telescope, which ones are easy to find and how to find them.
   • There is a Beginner's Target List here.
   • I also recommend Collins Gem Stars which is inexpensive, only shows objects visible in small telescopes and genuinely fits in your pocket. It has charts of the constellations indicating where the interesting objects are. It also has descriptions of the most popular objects.
   • To locate planets, you can search the web or buy a yearbook of some sort, such as the one available from Quasar Publishing.
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4. What kind of telescope/mount do you have?

   There are three popular systems:
   • Reflecting telescopes that come with equatorial tripods;
   • Reflecting telescopes that come on Dobsonian mounts;
   • Schmidt-Cassegrain telescopes with mounts that are fully electronic.
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   Telescopes with equatorial tripods

   More stuff to know about equatorial tripods:
   The mount will have quick-release controls for the RA and Dec axes. You release these when you want to move the telescope to a new position.
   It will also have slow-motion controls, often on long stalks. These are used to make small adjustments to centre the object in the spotter, to centre the object in the eyepiece and to track the object as it drifts out of the field of view.

   Step 1 - Get the tripod assembled

   Assemble the tripod according to the manufacturer's instructions or just make it look like the picture on the box. The elevation of the mount on the tripod head needs to be set so that the angle on the scale reads the same as your latitude. e.g. The latitude of Sydney is about 34 degrees south. In the Sydney area, set the angle on the mount to 34 degrees. This setting on a Super Polaris mount is pictured.

   Step 2 - Position the tripod outside

   • For night time observing, the axis of the mount (refer picture next section) should be aimed at the south celestial pole. This doesn't have to be particularly accurate if you are only using the telescope to look at things (as opposed to doing photography). The advantage, if you get it reasonably close, is that you can track an object as it moves across the sky by winding just the RA slow-motion control. If you get it wrong, you will need to wind both the RA and Dec slow-motion controls to keep the object in the eyepiece. You can find the south celestial pole using your planisphere to identify the Southern Cross (Crux) and Pointers (alpha and beta Centauri). Imagine a line drawn through the long axis of the Southern Cross intersecting with a line between the Pointers. The point of intersection is the south celestial pole.
   • An equatorial tripod should be placed on the ground so that the tripod sits level. This may require an adjustment to the legs if you have put it on uneven ground.
   • Before placing the telescope onto the mount, ensure the quick-release controls are locked so that the whole thing won't swing when you try to put the telescope onto the mount.
   • Install the counterweights, but at this point don't worry too much about where they should sit.

   Step 3 - Place the telescope into the mount

   The telescope should be placed in the cradle and the straps gently secured.
   Then you should check the balance:

   With the telescope at right angles to the mount, release the quick-release control for Dec. The telescope should not want to swivel around on the axis that runs through the counterweight shaft (refer arrow "a" in the picture). If you push it gently to one position, it should stay there. If it keeps tipping in one direction, you need to loosen off the straps on the cradle and slide the telescope tube towards the "high" or "light" end so that it is balanced in this axis. This is best done with the eyepiece in place as the weight of the eyepiece influences the balance point of the system. Once you are happy with the position of the telescope tube in the cradle, make sure the cradle straps are secured and then mark a couple of lines on the tube so you'll know where to sit it in the cradle next time. Tighten up the quick-release Dec control. Again with the telescope at right-angles to the mount, release the RA quick-release control. You should be able to swing the telescope to any position and it should stay there, balanced by the counterweights (refer arrow "b" in the picture). If it doesn't stay where you put it, adjust the positions of the counterweights up or down until the system seems well balanced in this axis.

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   Telescopes on Dobsonian mounts

   These don't do anything fancy. They are generally supplied assembled so there is no adjustment for balance.

   Step 1 - Plonk the mount on the ground

   Pick somewhere fairly level, but it doesn't have to be dead level.

   Step 2 - Place the telescope tube into the cradle

   The mount should revolve freely in azimuth (round and round) and the telescope should swing easily in altitude (up and down). The telescope should be balanced well enough to stop wherever you position it. If it is slightly out of balance, there should be enough friction in the system that it won't be a problem. There are ways of fiddling with more or less friction and also adjusting the balance. Email me for specific advice if you need it.
    
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   Telescopes with Electronic Mounts

   Generally these can be set up following the manufacturer's instructions. The tripod should be set approximately level, usually aimed roughly north. The telescope is attached and I recommend a two-star alignment if that option is available. The system will do a reasonably good job of finding the first alignment star. It is helpful to have a star chart or planisphere so you can identify the bright stars and make sure you are centring on the correct one. You will need to have the spotter aligned to get the alignment star centred in the eyepiece. If you successfully centre the two alignment stars, the telescope will then be able to find any target for you that is above the horizon. It won't understand trees and buildings being in the way!
    
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5. Setting up the telescope

   Step 1 - Remove lens caps

   Once you have the telescope tube installed on the mount, check that you have removed all the black caps: lens caps on the spotter scope; the cap where the eyepiece fits; the whole main cap of the telescope. With a reflector, the hole at the front of the telescope should be slightly larger than the diameter of the main mirror you can see at the base of the telescope.

   Step 2 - Insert an eyepiece

   Different eyepieces will yield different magnifications and the Barlow magnifies even more. High magnification just makes it harder to find things so beginners should leave the Barlow in the box and start with the eyepiece with the biggest number written on it.
   e.g. If you have a 25mm eyepiece and a 9mm eyepiece, choose the 25mm.
   The larger number provides the lower magnification, which is the best way to start. Read more about magnification, light gathering and resolution here.
   
   The eyepiece is inserted into the eyepiece holder and is secured with a little grub screw. Grub screws should be checked from time to time through the night as contraction with cold means that they can become loose without you noticing.
   
   Eyepieces themselves shouldn't rattle. If you have one that does, just screw the silver cylindrical bit clockwise back into the black head of the eyepiece and it should stop rattling. Don't ever pull your eyepieces apart.
    
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6. Aligning the spotter

   This is the most important step in setting up your telescope. If the spotter is not aligned, you have no hope of finding anything smaller than the Moon in the main telescope. Aligning the spotter is something that can be done in the daytime, though final adjustment is best done on a point source like a star.

   Step 1 - Decide on a suitable target by eye

   Position the telescope where it will be able to see something small and distinctive on the horizon in the distance. The telescope can be inside or outside, but the target should be more than two blocks away, the further the better. The target should be something you can see with your naked eye against the horizon. It could be the top of a light pole or mast, the pointy tip of a tree if it's not too windy, the corner of a building or a distinctive light at night. The telescope has to be able to see it too, so bend down to the height of the telescope and make sure your target doesn't disappear behind a fence!

   Step 2 - Locate the horizon in the telescope

   With an eyepiece inserted, look through the eyepiece and move the telescope so that it swings up and down, above and below the horizon. If you are on a tripod, you will need to release the quick-release controls so that you can move the telescope easily in any direction. Even without focus you should be able to tell by the difference in colour and brightness when you are on sky and when you are below the horizon. The daytime sky is bright blue and buildings and trees are darker browns and greens. The night-time sky is dark and below the horizon there will be lights and illuminated buildings and roads.
   
   Once you have located the horizon in the eyepiece, aim at anything just below the horizon and lock off the quick-release controls.

   Step 3 - Focus the eyepiece

   There will be a focus knob somewhere, usually just below the eyepiece. Turn it in either direction whilst looking through the eyepiece. If everything is still blurry, turn it the other way. Persist until you can get objects near the horizon into sharp focus. About now you might notice that the objects appear upside-down in the eyepiece. This is normal for an astronomical telescope. Everything is upside-down and back-to-front.

   Step 4 - Get your target in the telescope eyepiece

   Quick-release again and now pan along the horizon until that distinctive post, tree, building or light sweeps through your eyepiece. Centre on it as best you can, then lock off the quick-release controls. At this point the telescope may "sag" and the target may not stay in the eyepiece. If this happens, just use the slow-motion controls to fish around until you get the target nicely centred in the eyepiece again.

   Step 5 - Align the spotter to the main telescope

   Now comes the tricky bit. You have a target in the main telescope eyepiece and have locked off your tripod. If you have a Dobsonian, it's important in this next step to make sure you don't accidentally move the telescope off the target (keep checking!).
    

   1. What you're seeing

      • Look through the spotter scope. It is unlikely that the spotter will be looking at the target you have in your telescope eyepiece.
      • You will be adjusting the spotter so that it DOES look at the same object as your eyepiece. In other words, what you are seeing through the eyepiece will be nicely centred in the spotter.
      • If your spotter is a laser type, sometimes called a "Red Dot Finder", make sure it is switched on. You may have trouble in the daytime because it's hard to see the laser spot in daylight. Try again at dusk or at night. And don't forget to turn it off after use to conserve the battery life.
      • If you have a regular spotter with lenses, you should see a cross-hairs (like a gun-sight) when you look through the spotter.
   
   

   2. Methods of adjustment

      Different spotters have different methods of adjustment.
      • The laser spotters have two grub screws, one for up-and-down, one for side-to-side. These are fairly easy to adjust.
      • If you have only two grub screws to work with but the spotter is a lens-type sitting in a ring, the spotter is spring-loaded and you'll probably manage just by fiddling with the two grub screws one at a time. These are also fairly easy to adjust.
      • If you have three grub screws on the ring around the spotter, you may need to loosen all three, then position the spotter by hand and finally tighten the grub screws back onto the spotter carefully.
      • Sometimes they don't even give you grub screws and you have to use a screwdriver.
      In all cases, make sure you don't loosen the grub screws so far that they fall out (and if they do, let's hope you remembered to put that sheet on the ground!).
   
   

   3. Alignment technique

      So how are you supposed to get the spotter to aim at the right spot? You can't look through the eyepiece and the spotter simultaneously. But you did choose a target you could see with your naked eye. Here's how I do it:
      • Keep both eyes open.
      • Look through the spotter with one eye, and look directly at the target with the other eye. At the same time, fiddle with the grub screws thus wiggling the spotter around until the target is centred in the spotter. If it's a laser spotter or a spring-loaded one, that's all you need to do.
      • For a spotter mounted with three grub screws, it's a little harder to adjust and it's a matter of carefully backing off and tightening all the grub screws as needed so that the target stays centred. What will tend to happen is as soon as one of the grub screws tightens on the spotter, it will push the target off-centre, so back-off the grub screw just a fraction. Then tighten one of the other grub screws until the same thing happens. Keep working around the three grub screws until they are all tight and the target is still in the centre.
      • Then double-check in the eyepiece to make sure the target is still in the eyepiece as well. If it has moved, you need to re-centre it in the eyepiece first, and then go back to the spotter and try again. This is particularly a problem with Dobsonians. It helps to have a second person monitoring the eyepiece while you're fiddling and they can tell you if you've moved off-target.

   Step 6 - Final adjustment

   Once you have the spotter aligned, you should be able to aim the spotter at any other object (tree, light post, window) and be able to see it straight away in the eyepiece (which may need refocusing if the new target is at a different distance). For celestial objects, though, you need to line up the spotter on a bright star, check in the eyepiece where it should be visible, and then centre it properly in the eyepiece. You then may need to make any very small adjustments necessary to get that star right on the cross-hairs (or laser spot) when it is properly centred in the eyepiece. Note, however, that the stars will be moving due to the spin of the Earth while you are trying to do this, so make small adjustments only, and keep checking in the eyepiece frequently.
   
   The good news is that you shouldn't have to do this every time you use your telescope. The spotter alignment does go off slightly with expansion and contraction, but this is generally only a small adjustment. Driving it around in the car, however, is a different story. So after any trips check all the screws (on the whole telescope and tripod) and make sure nothing is loose or missing. This is the most likely time that the spotter will need re-aligning, but have a look at how good or bad it is before commencing any adjustments.
   
   The bad news is that some telescope spotters are so badly mounted that it is almost impossible to align the spotter properly. I have sometimes had to jam a piece of plastic (strips of plastic from the lid of an ice-cream container are suitable) inside the ring holding the spotter to take up the space where the grub screws ran out of length, but the spotter needed to be pushed still further over to one side of the ring. If even this doesn't work, take the whole thing back to the shop and complain.
    
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7. Finding objects in the sky

   Now that your spotter is properly aligned, you're ready to hunt down the Moon, planets, double stars, clusters and faint fuzzies. Try some of the objects on this Beginner's Target List.
   
   The procedure if using an equatorial tripod is:
   • Quick-release.
   • Slew the telescope whilst peering through the spotter scope with both eyes open until the target you're aiming for with your naked eye is centred in the spotter.
   • Tighten the quick-release controls.
   • Make any slow-motion adjustments to bring the target right into the centre of the spotter field.
   • Look through the eyepiece, adjust the focus and enjoy the view.
   • Start with the Moon so that you and any other observers with you can practice focusing and slow-motion tracking on something that is not going to rapidly drift out of the field of view. You also know for sure you're seeing the right thing if you can see craters and mountains. If all you're getting is a big bright featureless glow, you've probably lost your target and need to re-acquire it with the spotter.
   • To stay on the target, use the RA slow-motion control as often as needed to bring the target back to the centre of the eyepiece field.
   
   For a Dobsonian, just push it to where you want to look, using the spotter first and then looking in the eyepiece. To stay on target, just grab hold of the front of the tube and push it gently in the appropriate direction whilst looking through the eyepiece. If you push too hard, you may lose it and need to re-acquire the target in the spotter.
   
   For an electronic system, you should be able to key in targets or select them from menus. You may need to press "Enter" to select the target and then "Go To" to get the telescope to slew. If the alignment is a little off, you may need to make small adjustments to the position of the telescope using the hand-controller on its slowest speed setting to get the target properly centred. Once centred, the telescope should track automatically, staying on that object until you decide to move to a new target.
    
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8. About focus

   The focus adjustment is critical and it is important to remember that everyone's eyes are different. Partners and children will need to set their own focus and you will need to adjust it back for your eyes. Here are some tips:
   • It's best to wind through focus till it is out of focus on either side of correct focus and that way you can home in on the best focus position.
   • People with no experience may try to make the image bigger. The big image you may see when looking at a star that is badly out of focus is in fact a reflection of the primary mirror (large bright-filled circle) with a black spot in the middle (reflection of the shadow of the secondary mirror) and little black radiating lines (reflections of the shadows of the supports for the secondary mirror).
   • What you really need to do is to make the image as small as possible. As you get closer to focus, that big fuzzy bright circle will shrink down and down until eventually the star comes sharply into focus as a bright point of light.
   • You will never see a star "magnified". Stars only ever look like points of light because they are so very far away.
   • Planets can be resolved into disks when properly focused, so you can observe features like the rings of Saturn, dark belts across Jupiter, and phases of Venus and Mercury.
    
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Last Updated: 8 January 2024