Questions tagged [refractor-telescope]

Questions about telescopes with lenses as their main optical component.

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40 views

Verifying refractor lens about scratches

I found an used Skywatcher 70mm telescope for buying, but its lenses are a little suspect about harming. In one photo, it looks clearly a scratch, but in the another, it is not visible. Could it be an ...
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0answers
30 views

Methods for testing a refracting telescope lens

I have an old (nearly 50 years old)alt-azimuth three-inch (7.6cm) refracting telescope that someone else made. They ground the lens, created the cylindrical body and added a rack and pinion style ...
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1answer
54 views

How can I determine if a typical low-end telescope is a refractor or reflector?

Is there a way to distinguish (with no manual, product info etc)?
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1answer
74 views

What are the benefits of a large refracting telescope?

Currently, refractor telescopes are limited in aperture because gravity will deform the main lens over time. According to Wikipedia the largest practical refracting telescope is 1m. If we were to ...
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3answers
1k views

Chromatic aberration in lens

Is there a way to prevent chromatic aberration without using an achromatic lens in refracting telescopes or in any other instruments...?
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2answers
202 views

Second Telescope: Maksutov Cassegrain vs Refractor

I bought my first telescope, a 3-inch refractor a few weeks ago. It has been a wonderful experience seeing the Moon, Jupiter, Saturn magnified and Andromeda, M33, M81 and much more for the first time. ...
2
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1answer
101 views

Seeing a line rather than a dot when looking through refracting telescope

I bought an amateur(and rather cheap) refracting telescope and while I can see moon quite clear and crispy I am having difficulties in observing some larger stars. All stars appear as lines rather ...
3
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3answers
177 views

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

I am planning on buying my first telescope. I am getting an 80mm refractor and a 114mm reflector for the same price range. Which would be a better option? Further, would a Barlow lens solve the ...
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0answers
71 views

Can I couple (connect) a Reflector telescope and a refractor telescopes together?

I know it sounds crazy, but is it possible to connect a reflector telescope and a refractor telescopes (like monocular for bird watching) together to build a better telescope?
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1answer
396 views

Replacing Meade ETX with computerized mount

I've been using a Meade ETX 90 for a few years now. Since it doesn't have the new computerized mount (with goto), I am looking into buying one to swap out. Where might I find this and is there a more ...
2
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0answers
33 views

Equipment question

I'm looking to get some optical equipment that will be used for both terrestrial and astronomical viewing (ratio 70/30). It will also have to be portable to a degree although I realise that with a ...
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2answers
70 views

Stabilizers/dampers for refractor telescope

I have a basic refractor telescope. It's pretty light and so it catches vibrations and they never really settle down. Can I attach some dampers on it to cushion these?
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3answers
909 views

Question about Telescopes , observations and explanations of the observations

Though I am active on Physics, I am new to Astronomy. I am an amateur astronomer, actually even worse than amateur. I have just started it. I have a 60 mm objective 700mm focal length refractor which ...
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2answers
73 views

Capability of observing transits with terrestrial telescopes of various sizes?

I have access to my university's telescope, Dearborn Observatory, an 18.5 inch refractor on the shore of Lake Michigan, just north of Chicago (yes, it's an atrocious location, but the telescope still ...
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2answers
19k views

How to make a telescope for viewing planets, moon and DSOs using a convex lens of aperture 100 mm and focal length 200 mm and other lenses at home?

I wanted to make a telescope with DIY things lying around in home. I read up that the aperture was a very important aspect and thus bought a convex lens with 100mm aperture and 200mm focal length, to ...
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3answers
1k views

Astronomical telescope making

I am thinking about making a telescope. I have a 100cm focal length lens which I can use as objective lens in my telescope. So which is the best focal length I can use as eyepiece in my astronomical ...
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1answer
3k views

Are Barlow lenses stackable for bright objects?

I'm back to the refractor that I own, and I want to maximize the zoom capacity. I realized today that I own more than one barlow lens, and I was wondering if I could stack them together for looking at ...
11
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1answer
122 views

Does the Reflection Method for Looking at the Sun Work For Refractors?

I own a newtonian reflector and occasionally use it (using the reflection method with paper) for looking at the sun. I happen to also own a refractor, but I'm not exactly sure if the reflection method ...
14
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1answer
1k views

How Does a Refractor Telescope Work?

As I understand it, the difference between a reflector and a refractor is that a reflector uses mirrors on the back to reflect the light to the secondary mirror then the secondary mirror reflects the ...