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[su_box title=”Executive Summary” style=”soft”]The sky is huge and your scope shows only a small portion. Since not all the portions are equally interesting, you need to be able to find fun objects through three steps – aligning your finder tool, aligning your telescope, and navigating the sky. To align your finder tool (red dot finder, bulls-eye finder, or finder scope):
- Centre your finder tool on a distant object on the horizon (you can even do this in daylight);
- Look in your eyepiece and centre the scope on the same object;
- Go back to the finder tool, and WITHOUT MOVING YOUR TELESCOPE, use the little adjustment knobs or screws on your finder tool to re-centre your object in your finder tool.
Test your alignment by using your finder tool to pick a new object on the horizon. Then confirm in the eyepiece that you can see the object.[/su_box]
Preparing to view the sky
After people have run the gauntlet of buying a telescope (Dobsonian vs. Refractors, Reflectors vs. SCTs, equatorial vs. alt-azimuth mounts, etc.), choosing some eyepieces, and managing to get all the parts together with no pieces left over, they’re often ready for a mental break. So, they can perhaps be forgiven for thinking the hard work is over and that they’re ready for the easy viewing stage.
Generally, most newbies think, “Well, I can look up and see the moon or constellations, so I just need to point the telescope there and look.” Easy peasy, lemon squeezy.
Except not every patch of sky has something equally interesting to look at in your scope. If you start off with a low power view, you can see a circle in your scope about 1 degree in size. If you were doing bad math, you could say it is 180 degrees from the northern to the southern horizon, multiplied by 180 degrees from the eastern to the western horizon, for a “square-shaped” area of 32,400 degrees. So, you would essentially be picking one of the 30K+ regions to start looking. (As I said, that’s not the way the math works, but people get the scale – the sky is huge and your telescope lets you see itty bitty pieces of it at a time.)
In order to find the interesting objects, you need to be able to do three things:
- Align your finder tool to your telescope (PWG-A0008);
- Align your telescope to the sky (PWG-A0009); and,
- Navigate the sky to various objects (PWG-A0010).
Each step has some sub-options, and there is no “one best way”. You will need to find what works well for you and your scope.
STEP 1: ALIGN YOUR FINDER TOOL TO YOUR TELESCOPE
Every scope comes with some sort of “finder” tool on the top to help you navigate the stars better – the finder tool helps you get roughly in the vicinity of an object (macro adjustments) and then you use the actual telescope and eyepiece to lock in on your target (micro adjustments). Here are some examples of finder tools:
- A red dot finder – you look through a small plastic tube that projects a red dot on a piece of plexiglass between you and the background of the sky, and you move the scope to point the red dot at various stars to get your telescope pointing in that general direction;
- A red circle finder – usually either a Rigel Quickfinder or a Telrad tool, this is like the red dot finder, except instead of projecting a single red dot on the plexiglass, it projects a small bulls-eye target; or,
- A small finder scope – unlike the plastic finders, these are mini-scopes like your full telescope except with usually fixed, low power.
Whichever one you have, the purpose of the finder tool is the same – you use the finder tool to get the scope pointing near enough to the object to be able to find it in your eye piece, and then you do fine adjustments to centre it in your view.
But in order for this to work, you need to first make sure your finder tool and your telescope are both pointing at the same place. If you’ve ever tried to point to something with your finger and had someone else try to look down your arm to see what you’re pointing at, you know the problem…your finger and eye might be pointing at the same thing, but their eyes are not. So, they look down your arm to “align” themselves to your arm and fingers…with a finder scope, you need to do the same – align the finder scope to your telescope.
First, you start with pointing the finder tool at something on the horizon, and can even be done during the day! Pick something small that you can see with your eye – a distant light, the top of a telephone pole, an interesting tree limb that stands out, a chimney on a building. Get your finder tool pointing at it, as close to center as you can make it. Got your object? Great, step one is complete.
Step two is the telescope view. When you first look through it, it will likely be way out of focus so adjust that first. Once focused, the light, top of the pole, tree limb, or chimney will likely NOT be centred in your field of view. It may not even BE in the field of view! But if you move the scope slightly one way or the other, left and right, up and down, you can centre it (or find it first and then centre it!). Great, now your telescope is looking directly at the object.
Step three takes you back to the finder tool. When you go back and look at it now, you’ll see that while your telescope is looking dead centre on the object, your red dot or your red bulls-eye or your view in the finder scope are NOT dead centre anymore. In other words, your finder tool is not looking at exactly the same place as your main scope. But finder tools all have small adjustment screws or knobs on them.
** For this next part, DO NOT MOVE YOUR TELESCOPE. It is locked on a target (the light / pole / tree / chimney), and you want it to stay there. **
But you can adjust the view of the finder tool using the little knobs or screws. Some finder tools have two knobs – one for slightly up/down, one for slightly left/right. Some other finder tools have three knobs – two diagonals and a vertical. It can be a bit finicky the first time you do it, but it is not hard. Adjust the view of your finder tool to be back on the same object as before.
When you’re done, what does this mean? It should mean that both your telescope are looking exactly at the same small object on the horizon (light, pole, tree, chimney) and so now when you point the finder tool at something, your telescope HAS to be pointing at the same thing.
Test it. Use your finder tool to pick out another object, centre it, and then look in your eyepiece on the telescope. It should be close to centre in your eyepiece. It has to be – you just aligned your friend’s eyes to your arm and finger! It points to the same place.
[su_box title=”Tips” style=”soft”]Do your first few alignments during the day. It is easier to see what you are doing with the fine adjustments. Later, when you are more experienced, you can do it at night on a bright star or distant light on the horizon.
Every time you use your telescope, you’ll need to test your alignment. It may be dead on each setup, but you are more likely to need a fine tuning each time. It just makes life easier … the more precise you are on this alignment, the more likely you are to find your objects on the first go rather than having to scan the region when you switch to the telescope view.
The smaller the object and the greater the distance, the better target it is. Centring on a building a block away is a huge margin of error; centring on a red light on the top of a tower three kilometers away is a much smaller margin of error. Remember – you’ll be targeting small stars in the sky, so precision is key.[/su_box]