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13 votes
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What's the difference between a Newtonian telescope and a regular telescope

First off, I would not recommend any of these telescopes. Of the ones you listed, the 114EQ is the least bad choice. But, due to the poor quality of its mount, it's the better of the bunch. Ok, ...
J.M. Haynes's user avatar
  • 1,058
13 votes
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Could someone explain what is wrong with my telescope, and what should I be able to see with it?

Welcome to the wonderful world of visual astronomy! The first thing I would like to point out is that, when you are talking about “zooming in,” you’re actually adjusting focus—placing the eyepiece ...
Pierre Paquette's user avatar
11 votes

Could someone explain what is wrong with my telescope, and what should I be able to see with it?

I suggest you take your scope out during the day and look at the most distant object on land (or sea) that you can see: a building, tower, or tree. Start with the 25 mm eyepiece and turn the focus ...
JohnHoltz's user avatar
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9 votes
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Mars looks like a blur

There's another answer here claiming that an off-axis aperture mask will improve things. That is a fairly popular meme, but it's entirely incorrect, and makes misleading claims about the effects of ...
Florin Andrei's user avatar
9 votes
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Betelgeuse appears in a rainbow of colors through a Newtonian telescope

...pulsing bright rainbow of colors... Sounds like very bad astronomical seeing effects. Even a steady atmosphere acts like a weak prism and in fact all dielectrics tend to bend blue light more than ...
uhoh's user avatar
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6 votes
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Why are Cassegrain telescopes shorter than Newtonian reflecting telescopes?

Basically, the light has a longer way to go after hitting the secondary mirror in a Cassegrain than in a Newton telescope. In a Newton telescope (top image), the light hits the primary mirror and ...
usernumber's user avatar
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5 votes
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Under what situations can an aperture mask improve the resolution of a small/medium amateur telescope? Is this demonstrable mathematically?

The vast majority of people - almost everyone, really - should not rely on this on a daily basis. The chances are overwhelming that they will reduce the performance of their instruments. There are so ...
Florin Andrei's user avatar
5 votes
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I need help getting mars to look like a circle

I have made sure that the laser is straight by 1. spinning it in the eyepiece holder and the laser stayed in the same spot 2. zooming in and out and again the laser stayed in the same place. the ...
Florin Andrei's user avatar
5 votes
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Help stabilizing telescope

A "Celestron Powerseeker 114AZ" Google turns up old reviews at Amazon.com and .ca. Most are somewhat critical of the mount. In all honesty that is to be expected at this level. Many amateur ...
L d Bonnie's user avatar
5 votes

Could someone explain what is wrong with my telescope, and what should I be able to see with it?

Even if your telescope is correctly set up, its short focal length of 650mm is not ideal for observing details of the moon and planets. You should get one or two more eyepieces with a shorter focal ...
Thomas's user avatar
  • 3,494
5 votes
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How to locate M13, Ring Nebula?

The ring nebula (also called M57) is quite beautiful and relatively easy to find! It is located in the constellation Lyra---which will be easy to find since it has one of the brightest stars in the ...
Keyan Gootkin's user avatar
4 votes

How could a hobbyist astronomer determine apparent magnitude of a star?

There is a difficulty with measuring magnitude: the atmosphere! It is sometimes clear sometimes hazy and it can be very hard to know just how much light is being lost to a high layer of thin ...
James K's user avatar
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4 votes

Why are Cassegrain telescopes shorter than Newtonian reflecting telescopes?

The Focal Length is not really the distance the light travels from the objective. The Focal Length is the diameter of the aperture divided by the tangent of the angle at which light rays from the ...
antlersoft's user avatar
  • 3,455
4 votes

Is there a reflecting telescope like as a Newtonian telescope but with a negative lens before the diagonal mirror?

Yes! Those with a Coudé focus and others The following this answer to Why aren't reflector telescopes built with an offset secondary mirror? this answer to Do telescopes exist that reflect the ...
uhoh's user avatar
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3 votes

Best telescope for astronomy

"Galaxies and nebula" are faint and spread out, and for that very little matters as much as aperture! Back before light pollution was a a serious problem, 6 inches (150 mm) was generally acceptable, ...
tomc's user avatar
  • 463
3 votes
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Did Edmund Scientific 4¼ inch Newtonians have 90° prisms as secondary mirrors in the 1970's?

My Edmund F/10 4 1/4" was bought in 1975, and had a rectangular front-surface mirror as the diagonal, with a single arm support attached to the tube near the eyepiece holder. I believe the Astroscan ...
antlersoft's user avatar
  • 3,455
3 votes

Advice on first Telescope (refractor vs reflector), Barlow lens

Further would a Barlow lens solve the chromatic aberration issues with a f/5 refractor. I suppose in theory they could, but they would have to be designed to do so. In practice, they vary widely in ...
Alphecca's user avatar
  • 696
3 votes

How does diffraction occur in a reflecting telescope?

Diffraction has nothing to do with whether you are using a lens or a mirror in your telescope. Diffraction occurs for the same reason in reflecting telescopes as it does in refracting telescopes: it ...
usernumber's user avatar
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3 votes
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Newtonian reflector collimation question

Your scope is f/5. There will always be some coma aberration. Always, the image quality is worse as you get closer to the edge of the field of view (FOV). Personally, given that the fact that you will ...
astromath's user avatar
  • 316
3 votes

What's the difference between a Newtonian telescope and a regular telescope

A "Newtonian" reflector has a main mirror which is curved and focuses the light back up the tube. It then has a secondary flat mirror at an angle which reflects the image sideways. A Newtonian ...
James K's user avatar
  • 123k
3 votes
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Collimating with a home-made collimation cap

The Gary Seronik website that you cite is a good one - it's not leading you astray! There are a couple of important things to look at: Look straight down the main tube of your telescope at the ...
MartinV's user avatar
  • 644
3 votes
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Why does any planet look like a (not so) big white ball through my telescope?

It seems that you haven't align properly your finder (or) laser. You can align at day with a chimney, but at night you must start with the moon and after that you are sure that you are pointing ...
Antonio Baena Guerrero's user avatar
3 votes

Improving portability of truss Newtonian

I have two options, but the experts might not like them. The first is to replace the carbon fiber poles with telescopic tubing similar to that used for camera tripods, but maybe a bit more robust. The ...
Fred's user avatar
  • 2,169
3 votes

Is there any specific way to record observations on any celestial object while looking through a telescope?

There are several observational astronomy tasks that have traditionally had active amateur participation. The important things to note will vary depending on the task, but will include the precise ...
antlersoft's user avatar
  • 3,455
2 votes

Does making a ground based telescope larger always give you a better resolution?? why?? or why not?

The diffraction limit of telescope optics, for apertures large compared to the wavelength of light, is inversely proportional to the diameter of the aperture. See the relevant Wikipedia page. For ...
Conrad Turner's user avatar
2 votes

Are Barlow Lenses Good For Deep Sky Observing?

You can get a simple formula for making an aperture mask (just a circle with the diameter of your tube, but with a smaller circle cut into it--templates are available). This creates an "off axis&...
California Dobsonian Guy's user avatar
2 votes
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Retrofitting a DSLR camera to a super-cheap Tasco reflector telescope

The problem you have with many newtonian reflectors - especially smaller ones - is that to use them for prime focus photography (where you're effectively using the telescope like a big telephoto lens) ...
JerryTheC's user avatar
  • 654
2 votes

About bigger resolution of telescopes

It's a large reflecting telescope, which is more effective than the more familiar lens telescope. Also, in space, less stabilization is needed. As long as the rotation is very close to zero, ...
userLTK's user avatar
  • 24.1k
2 votes
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Using setting circle for Right Ascension

I think I mis-read your question before. Let me rephrase it to make sure I understand. In step D (moving the scope from Sirius to M42), that process took 5 minutes to complete. Or maybe it took 30 ...
JohnHoltz's user avatar
  • 8,032

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