Hello, I know that question sounds stupid, but let me explain first. I know how to use telescopes fairly well and have been for years, but last year I was given a small 4.5" reflector scope that a friend didn't use any more, and I can't seem to get a crisp image with it at all. When looking at stars or planets I can never get it to focus sharp. where it should be sharp it has a fuzzy halo around the star/planet and you just see a blob of fuzz. It's so bad that I can't see the rings of Saturn or the cloud belts on Jupiter. I've checked and cleaned all the mirrors and eye pieces and they seem to all be in good condition. No scratches or anything that I can see. Any ideas on what's causing this or what I might be able to do to remedy this would be greatly appreciated. Thanks for your time and help.
2007-12-15 13:26:27 · 10 answers · asked by dragon_slayer79 2 in Science & Mathematics ➔ Astronomy & Space
I should clear this up when I said "when it should be in focus it's fuzzy and has a halo around it" I'm referring to attempting to focus using the eyepiece focus.
2007-12-15 13:34:34 · update #1
Also is it worth messing with or is it going to be cheaper to replace than to repair? Thanks.
2007-12-15 13:37:00 · update #2
The scope is a Celestron 4.5" Newtonian 1000mm f/L No model number is specified on the scope.
2007-12-15 13:54:58 · update #3
Cleaning was only done with a dry micro-fiber cloth wiping in one direction to avoid grinding any dust/debris into the surface.
2007-12-15 13:56:59 · update #4
Reflector telescopes require precise alignment of the primary and secondary mirrors.
Over time, through normal jostling and moving the scope those mirrors can become slightly misaligned resulting in poor or out-of-focus images.
They need to be periodically adjusted (called "collimation") to keep that precise alignment.
You can do it yourself - you need a collimator and instructions (a good telescope store can sell you both).
2007-12-15 13:36:32 · answer #1 · answered by Anonymous · 2⤊ 0⤋
The question is not stupid. You did not mention the make of the scope. My suspicion is:
1. It is so far out of collimation that it is almost trying to look sideways out through the tube.
2. The eyepiece is so poor that you cannot see through it.
You may want to set it up in daylight hours and try to focus on a distant object. If you cannot, then I would try collimating the scope. There are many sources available on how to do this. If the eyepiece is cheap junk, you should probably consider throwing the scope away and starting over.
2007-12-15 13:42:18 · answer #2 · answered by Larry454 7 · 1⤊ 0⤋
As several people have mentioned, an old Newtonian is almost certain to need collimation. Also, some cheap telescopes have very poor optics. If collimation doesn't fix it, try a better eyepiece. If that doesn't work, one or both of the scope's mirrors is crap, and the best you can do is see what parts you can salvage to build a working telescope.
2007-12-15 16:02:47 · answer #3 · answered by injanier 7 · 0⤊ 0⤋
I'm a bit alarmed by reading that you've cleaned the optical surfaces. This should only be done with special solutions, and very carefully. You can take the coatings off the glass if you use other detergents or chemicals.
I'd agree, though, with the collimation being out. Are you at low power to begin with? And the quality of the scope may also be questionable. What make and model is it?
2007-12-15 13:51:32 · answer #4 · answered by Anonymous · 2⤊ 0⤋
It sounds like you need to colluminate your telescope. If you read the instruction manual you will find detailed instructions on how to do that. You will need to purchase or borrow a special LED accessory to do that.
Also, once colluminated (spelling ???) you will need to adjust the focuser knob very slowly as you approach best focus, pass thru best focus, and then come back to just right.
This telescope is a beginners model (4.5 Inch Mirror) and fairly light weight. So it is easy to move around = portable.
Being small and light weight, it is easy to knock out of alignment. so you need to learn how to align it. This is done very carefully with all of the right tools, or you will ruin a possibly nice little scope.
2007-12-15 15:09:11 · answer #5 · answered by zahbudar 6 · 0⤊ 0⤋
Oh, but they do. Telescopes need to be focused for the person looking through them. Stars are pinpoints of light, so the focus may not have to be as exact as with binoculars, but if you're looking at a nebula or the moon or such, you must focus the telescope. I used to teach astronomy, and each student would need to focus when we were looking at a planet or nebula. Stars are never more than pinpoints, but you still want a clear pinpoint!
2016-04-09 05:50:58 · answer #6 · answered by ? 4 · 0⤊ 0⤋
i could tell you... but then you would hate me.
so, instead I will suggest trying to contact a local Amatuer Astronomy group in your area or check out any local observatories that might have an Open Viewing Night. Those guys not only can tell you what's going on, but help you fix it faster than you can say "Halliburton".
2007-12-15 13:32:46 · answer #7 · answered by Faesson 7 · 2⤊ 0⤋
You should be able to focus by moving the eyepiece back and forth.
2007-12-15 13:32:00 · answer #8 · answered by Anonymous · 0⤊ 0⤋
It sounds to me like you desperately need to collimate your scope.
2007-12-15 14:14:15 · answer #9 · answered by B. 7 · 2⤊ 0⤋
I'm betting that the mirror(s) have been wacked out of alignment.
2007-12-15 13:35:32 · answer #10 · answered by Chug-a-Lug 7 · 2⤊ 1⤋