Using my telescope

Last Edited By Krjb Donovan
Last Updated: Mar 11, 2014 07:56 PM GMT

Question

Hey Tom,

Can you please direct me as to how to line up my telescope to view the moon? I got it as a Christmas present and have tried to view the moon several times but either only get a light blur or nothing but a solid color. I'm not even sure if it's adjusted or needs to be or what... I followed the instructions to set it up and used the short guide provided with it to attempt to use it. it came with a 10mm and 20mm lens, don't know which to use, and at the end of the tube there is a small middle section you can remove and a larger round plastic section that fits around the smaller inner middle section...i also don't know if i should remove both or just the smaller. thanks alot in advance, i'm a first timer and major noob when it comes to this stuff so please feel free to talk to me like i have no idea what i'm doing, because i don't. but i'd really like to be able to explore the night sky. It's been a hobby that's been too expensive for me to explore until now and i'd really like to atleast be able to look at the moon!

here is the link to my telescope: http://www.celestron.com/c3/product.php?CatID=62&ProdID=427


thanks, -Tim

Answer

Hi Tim, Unfortunately, later on, once you enter our great hobby the correct way, after you read our website which I'll give you later, you'll still need....a good working telescope. Not the one you have...a different one.

It's not the lining up on the moon, you obviously can do that.  It's the image....If the image is blurry, then the problem is that

it's not focused correctly. It's either the eyepiece is not at the focal point of the telescope, (move it in or out farther....put it on a bright star and bring the star down to a small pinpoint.... OR it's out of collimation (the optical axis, the mirrors and eyepiece, are not aligned properly)- so collimate it first. That's usually the main problem. Shipping will usually bump and tilt the secondary mirror out of collimation....you have to first learn how to collimate a telescope, as we all did. (Oh, and BTW, the moon is not a good 'test' for a scope, it's too close and too big...try splitting a close double star (Mizar in the Dipper handle will do, initially, with Polaris next).

Next are the eyepieces; always use your lowest power eyepiece first...if sharp focus (high resolution) cannot be obtained at low power, it only gets worse at higher powers. Perhaps you need an eyepiece extender to get the eyepiece out farther from the tube...this is best done in the daytime on a distant telephone pole or stop sign.....to find the correct focal point. Lastly, quality of grind or figure on the mirror might be worse than 1/4 wave, so all the light is not coming to a common focus. This is a major problem with very inexpensive telescopes (typically scopes worth less than $500)....that's why you see them in garage sales and flea markets for a fraction of their new price because.... they just flat don't work, except on terrestial objects, which don't have the very high requirement for exquisite optics, as does astronomy.....it's called - resolution; of separating 2 energy sources or objects, very close together. That's why we use close double stars as our real testing. Oh, one other problem...you aren't looking thru a plate glass window are you? They certainly aren't ground to 1/4 wavelength of light, or looking from a warm room out into the night sky, OR did you allow the scope to cool down outside at least 30 minutes prior so that all the optics are at or perhaps only 1 or 2 degrees above the outside ambient air temperature. ALL scopes have to meet that requirement before fine observing can be obtained, as we are dealing with millionths of an inch here....scopes are super-sensitive to changing temperatures, so that has to be eliminated! (I think you see that this hobby requires a little more work and knowledge than what you were prepared for, now).

WHAT you have missed in your studies of astronomy, is that EQUIPMENT (scopes) come LAST in our great hobby, not first. Knowledge (as you are finding the hard way) comes first. Plus, did you inform the giver of the gift what your main specialty will be? Lunar/Planetary details, deep sky objects, comet hunting, variable star work, asteroid hunting, nova hunting, etc? There is a scope out there that maximizes each of these objects and that's the one you want once you decide. (Otherwise, we'd all have the same type scope, wouldn't we? But we don't...there are different scopes for different folks. Telescopes are like airplanes, all airplanes fly, but you don't send a bomber to do a fighter's job. Scopes are exactly the same way.

Suggest you take a minute to read, "Tom Whiting's sound advice for the Novice Observer" at http://www.velocity.net/~bwhiting and then, let's try some more questions on Novice astronomy. And BTW. we call them "eyepieces" not lenses....to differentiate between the front lens of a refractor type telescope...which IS a lens. Hope this helps, Clear Skies, Tom Whiting Erie, PA

Advertisement

©2021 eLuminary LLC. All rights reserved.