Friday, January 20, 2012

Checking a Telescope at a Store

So you see a telescope at a store and you want to check it out. What do you do?

You can only get the most basic idea of the optics while it's in a store, but you can check it out mechanically pretty well. The mount is actually more important than the optics for most starter scopes. So you can get a pretty good idea of a scope, even in the store.

commercial Dobsonian telescope


Mount Stability

Put the scope at different angles then see if it says where you put it. What does it take to make it move off-target? If it moves on its own, it may need balancing. Or it may be junk. If it moves when touched lightly, the same is true. If the mount seems like it might be stable, see if you can balance the scope. This will also tell you if the scope is built to be balanced against the effects of eyepieces or accessories of different weights.

Once balanced, it should be possible to get the scope to stay wherever you put it. If there are locking mechanisms that hold it in place, do they cause the telescope to move visibly when you engage them? If so, that's not good.

How does the scope react to being tapped? Does it stay on target? It should. How about light pressure? Stronger pressure? A thump, like an accidental bump with the arm?

Pretend to swap out eyepieces. Does it stay put as you remove and reinsert the eyepiece? You'll be doing this a lot. You find something at low powers, then swap in a higher power eyepiece. If the scope doesn't stay on target, you'll be frustrated whenever you try to increase magnification, since higher power eyepieces see a smaller area of the sky than lower powers. Which makes finding your subject more difficult if you have to do it with the high power eyepiece all over again.

Focuser Stability

When you adjust focus, does the eyepiece wobble at all or does it travel smoothly along its axis? Once its in a place, can it be jiggled--either in and out or side to side? If so, these are all signs of a poorly made focuser. Are the materials it's made of solid or a bit flexible? They should be rock solid.

Does it hold eyepieces securely, or loosely? You want secure.

Adjustability

If the scope's height is adjustable, can it be moved securely, and does it stay put? Some mounts are only supposed to be adjusted when the scope isn't on them. That's fine. But once it's in place does it stay put? Do any of the stand adjustments present a safety risk to the user? Does the mount allow the telescope to be put on safely? I've known people with high-end name brand telescopes who risk their scope every time they set it up or take it down. Eventually the dice roll against them, and the telescope gets dropped and broken. You may not be in a position to set up or take down the scope in the store, but you can ask. Or have them demonstrate it.

Look for places where you can't be sure of whether something is properly in place or not, or where you're not sure if something is engaged until you let go and see if it starts to fall. You don't want that.

Finder Scope

You should be able to use the finder at any angle from horizontal to straight up without undue strain. You should certainly be able to look through it without bumping your head into the telescope. It should be secure as well. and the adjustments to align it with the main telescope should be easy to use. It won't be any use if you can't line it up easily.

Overall construction

Overall, the scope and mount should use solid quality material. It should feel and function like a precision piece of machinery. Tubes made of plastic or heavy paper-type materials are OK, but they should not be at all floppy--they must support themselves and the optical components accurately and firmly. Any sag or wobbliness are trouble.

The scope should be soundly seated on or secured to the mount.

The mount should be stable and firm.

The optics should adjust smoothly, stay put when they're put in place (the eyepiece or focuser shouldn't creep or wobble).

Also, the scope shouldn't have parts that interfere with its proper use for the sake of cosmetic appearance. Like bulgy plastic dew shields or molded plastic part covers.
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Saturday, January 7, 2012

Learn to Use Your New Telescope!

Did you get a new telescope recently? This is the time when the most new telescope owners are made!

Using a telescope isn't entirely natural and easy, no matter what scope you have. In fact, the scopes with the most "ease of use" features are often the hardest to get started with.

A local astronomy club is a good way to find others who can help you learn more about how the get the most out of your telescope. They're using their own telescopes, they will know some good places to use them, vital accessories for them (very few telescopes are sold with everything they really need to be useful), and have tips. The club may have formal classes, or just give you the chance to meet up with others with like interests to yours, and more experience.

There's information available online, but having someone who can actually be there with you and your scope, even if just for a short observing session or daytime practice session, can be invaluable. They can see things in a moment that you won't know to mention online. They can tell you things just as quickly that would make for long murky postings online. The "personal touch" makes all the difference.

Also, don't beat yourself up while you're learning. Learning to see things through a telescope is something you have to do. It's not natural like looking with your eyes without an instrument. If you're experienced with using other optical instruments like binoculars or microscopes it'll help, but a telescope is still a different animal that takes getting used to.

Don't set yourself up for failure by expecting to see observatory photograph views of difficult objects. The Horsehead Nebula doesn't look like the pictures to eye, and it's very, very hard to see even with the correct telescope and accessories. Start by looking at things chosen from a naked-eye astronomy book or binocular astronomy book. Train yourself to find the objects, keep your scope on them, and see the detail in them.

Each scope behaves differently, and you will want to get experience seeing what your scope shows. It's a matter of experience, and you'll find there are several different levels you can achieve as your skills develop. Regular repetition with the right equipment is the key to developing. Each new level brings a new level of enjoyment. Things that didn't look like much before suddenly become far more interesting, even if the equipment hasn't changed at all. You learn to see an notice things that weren't apparent before.

Plus you'll need to learn to be patient and give your eye the time to see what you're looking at. Most beginners spend far too little time actually looking through the eyepiece and relaxing once they've got something to see in it. Your relaxed eye will see far more than an eye that is rushed through a quick "there it is!" look.

Keep your scope stored in a state and location where you can easily use it. Its size and type matter far less in its performance than whether it is simply taken out an used regularly.

If you seem to be hitting a wall, there may be something that needs to change with the equipment, or that you need to know about how to use it. Don't be discouraged, find an answer. Astronomy is not supposed to be difficult. If you find that it is, suspect that there's something else you could be doing other than what you are doing.

Don't be daunted by the fact that there are things to learn. The process of learning them is (or should be) a pleasure in itself. There are many ways to approach doing astronomy, none of the good ways require an overabundance of patience or muleheadedness or a giant egg-shaped head. All they take is normality, an interest, and the ability to ask questions and occasionally follow directions.
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Sunday, January 1, 2012

Good Time for Bargains, But Watch Out!

This is a good time to find bargains on telescopes. There are many used scopes for sale as folks seek to clear room for new acquisitions in their homes, or raise money to pay the holiday bills. Stores also receive many returns that are re-sold at low prices. Plus they may have overstock that they are looking to clear out.

One thing to watch out for, though, is the ever-present junk scopes, especially if it's a telescope being purchased for a youngster. These aren't bargains at any price. Find yourself a scope with a good price, but first and foremost, remember that it's a scope that should be quality.

A good mount is critical. Half your budget or more should go to ensuring that you can point your scope at what you want to see, and keep it on while you observe.

Many wishes for a happy new year of telescope use!
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