Stargazing Planning to buy a first telescope? - Comments

davenn

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long time ago I had small telescope with max 40x magnification but I was not satisfied by it, mainly because it was very unstable where the least wind causes shaking and everything I see through it was very blurry including nearby planets like Mars and Venus.
well that is what happens with a cheap scope and mount

Quality cost money

again I aim you at the thread V50 posted where all this is discussed

https://www.physicsforums.com/threads/planning-to-buy-a-first-telescope.391086/


So, what sort of budget do you have ? and keep in mind that something stable is going to cost
~ US$500 and up. Buying something less that ~ US$500 is going to give you all the same problems
that you had with that first scope


Dave
 
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Drakkith

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So, what sort of budget do you have ? and keep in mind that something stable is going to cost
~ US$500 and up. Buying something less that ~ US$500 is going to give you all the same problems
that you had with that first scope
I'm not sure I agree that you need to spend upwards of US$500 to get a 'stable' scope. As long as you avoid the extremely low end of the price spectrum, under 100-150 USD, I think you can get a decent starter scope. Obviously it wont be nearly as stable in wind as my 8-inch reflector on my Orion Atlas mount and tripod, but it also doesn't weigh 70+ pounds and it doesn't need to be as stable anyways. I believe I spent somewhere between $150 and $250 to get a small computerized reflector on an alt-az mount that worked great for me. It was light enough to easily take outside, and sturdy enough to not be blown about by the slightest breeze.
 
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Thanks all for your valuable advices..

My budget is $600 max, so what technical specs should I aim for under this budget?

Also I would like to see some stars and galaxies I am not sure if that will be possible under this budget.
 
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davenn

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I'm not sure I agree that you need to spend upwards of US$500 to get a 'stable' scope.

That's why I said "around" … not overly familiar with American pricing without delving into it

My budget is $600 max, so what technical specs should I aim for under this budget?
OK I don't know what country you are in ? …. here at B&H as an example …..

This would be an excellent start

https://www.bhphotovideo.com/c/product/1248233-REG/celestron_22203_astro_fi_130mm_f_5.html

a good quality brand … I own a Celestron myself …. a bit bigger than that one :wink:

that one is well within your budget and I see it has ports on it for handheld controller and auto guider ( if you wanted to get into that at a later date

It is very important that the mount is solid else you will still be plagued with vibrations every time you touch it to do focussing etc


if you could push your budget a little bit more, you could aim for something like this …..

https://www.bhphotovideo.com/c/product/440825-REG/Celestron_11068_NexStar_6_SE_6_0_150mm.html


on the other hand, if you want to do away with all the drive abilities, you could go with a dobsonian like this

https://www.bhphotovideo.com/c/product/1141702-REG/sky_watcher_s11610_8_traditional_dobsonian.html

I have also owned similar in recent years


There's some thoughts for you

cheers
Dave
 

Chronos

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Nice list, Dave. The F! has enough aperture to actually see some interesting things. If computer control is not a 'must', the Meade Polaris is virtually the same scope on a much nicer mount at half the price.
 
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@davenn
I am comparing the The SkyWatcher with the Celestron NexStar.
The SkyWatcher seems better to me .. it has larger aperture of 8 inch (vs 6 inch for Celestron) and comes at half price $378 (vs 750$ for Celestron).

In general should I aim for the largest aperture when deciding which telescope to buy?
 

Drakkith

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In general should I aim for the largest aperture when deciding which telescope to buy?
If the additional weight isn't a problem, then yes. You should usually aim for a larger aperture over a smaller aperture for a general purpose telescope (one that you aren't using specifically for something like astrophotography or something).
 

Chronos

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As Drak said your priority should be as much aperture as you can manage. The purpose of a scope is to gather light and the more you can gather the better so long as you can manage to prepare it for a viewing session. There is no accessory at any price that can increase the amount of light your scope can collect. Personally, i prefer an equatorial mount, but, I am old and lazy - so only needing to move the thing in one direction [along a single axis] to keep something in view appeals to me. It also vastly simplifies finding a new target at the same declination or right ascension.
 

sophiecentaur

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on the other hand, if you want to do away with all the drive abilities, you could go with a dobsonian like this
A dobsonian has many advantages in that is a very simple arrangement. The mounts are often totally manual so you very rapidly find how to locate the objects you want to observe by 'star hopping'. (Starting with a well known star and then hopping between less well known stars, following the instructions you can find in books like "Turn Left at Orion") That's the way all amateur astronomers used to observe. If you buy a 'Go To' mount, that can take up most of a limited budget, before you even start paying for optics. Admittedly, you can be up and running quicker with a goto - but you still have to align the mount before you can point to most objects.
The first telescope I bought was an 8" Dobs and I was staggered by the view it gave. I compared it with smaller, go-to systems and I was more than pleased with my decision. You very quickly learn how to collimate a newtonian telescope and that's pretty much the limit of where a Dobs can go wrong. If your budget is limited, you will probably need to pay someone to sort out any problem with the mount and that could mean waiting till you have more money.
I got rid of my Dobs because my joints couldn't cope with the antics involved in kneeling on the ground and squinting through the finder scope. That's just a problem with age!!
I would agree with the comments about binoculars, though. Even a modest pair will reveal so many objects. You would need a fairly steady tripod, though, and binoculars with a thread for mounting to a tripod. Afaiaa, any decent bins (reasonable birding binoculars) will be suitable.
 
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Also I would like to see some stars and galaxies I am not sure if that will be possible under this budget.
I guess you are aware of that, but better to emphasize it: except the Sun, you won't be able to resolve any other individual star as "a disc". They all appear as a point-like sources in any amateur scope.

Regarding galaxies, the most important is to have dark sky - light pollution is a serious obstacle. And as mentioned in many posts above, bigger aperture is better, especially for deep-sky objects like galaxies. There are few galaxies you can see with a naked if the sky is dark enough, like M31 Andromeda.
 

Chronos

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A right angle finder scope is on my 'must have' list for a newt or dob..
 

sophiecentaur

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A right angle finder scope is on my 'must have' list for a newt or dob..
It's a 'must' - and it's something I bought PDQ, but you still need to 'sight' along the telescope barrel to get an initial pointing direction. No problem for a youngster without a 'bad' neck and back. I resorted to putting the scope on a firm table - then having to get up on a chair so that I could see through the scope (amusing to watch, I expect!!). But the views through my Dobs were really cracking at times. You can't beat a light bucket for low cost visual.
 
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A right angle finder scope is on my 'must have' list for a newt or dob..
Also Telrad finder on my dob is pretty useful, I like it a lot. Since I use it, I do spend less time finding the objects, and more time observing them. But indeed, it often requires some physical exercise, especially for the targets near zenit :smile:
 

sophiecentaur

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I acquired a Telrad for free, quite recently.It really does the job - especially when looking for nice bright alignment stars. You are viewing with no magnification so the brain needn't work quite so hard. The image is also the right way up! I think one should have two on a scope to reduce the Yoga aspect of Astronomy, though.
 

jim hardy

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A dobsonian has many advantages in that is a very simple arrangement.
And it lends itself to fabrication at home with just basic tools. One might buy a secondhand EDIT department department store scope for very litt;e and make himself a decent mount for it.

Another thought - i have a friend who's an avid shooter. His inexpensive spotting scope does a great job on Saturn's rings .
 
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sophiecentaur

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"department"? I couldn't think what work the spellcheck substituted in order to get department. :smile:
 

jim hardy

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"department"? I couldn't think what work the spellcheck substituted in order to get department. :smile:
OOPS i meant "Department Store" telescope.
Some actually have a decent mirror but they come with ridiculous eyepieces and flimsy tripods..
Since power sells they'll come with eyepieces having way too short focal length to be practical. Just try to hold a 400X 'scope still let alone find something with it.

One can take apart a thrown away "Point & Shoot" film camera and get a decent lens around 35 mm focal length. Such cameras bring just a couple bucks around here.
With some whittling and glue he can fashion a wood eyepiece from an old sewing spool,
and get surprising views of our and Jupiter's moons at 15 to 30X on a 'department store' scope. For probably under twenty bucks.

It's a cheap and fun way to get started.
And it might make a good finder for your serious 'big telescope' later on .

now i'll fix that post.. old jim

PS sorry for digression. Maybe i shoulda started one in the DIY thread.
 
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sophiecentaur

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Maybe i shoulda started one in the DIY thread.
That was a classic @jim hardy post and I enjoyed it. :wink:
Interestingly, (well, to me at least) I just purchased a half decent model (mini) lathe and the first real job I have done was to make a mount for some non-standard filters that @Andy Resnick sent me. Not a bad piece of lathe work, if I may say so, and it involved putting a 47mm X 0.75mm on the barrel. Thanks Andy - I have actually done something about that interesting package you sent me!! I will be doing more DIY astronomy construction shortly.

PS The problem with DIYing scopes is more to do with the focusser than an eyepiece, I think. It would be quite a challenge to mount a gash lens onto a Newtonian reflector though my lathe could help . . . . .
There are some very entertaining descriptions of building a Dobsonian to be found with a Google search.
 
Great article.

What kind of telescope to get depends upon what you want to do, as different telescopes may be good for different goals.

When trying to decide, keep in mind how different types of telescopes work, and you should become familiar with the ideas behind abberation, and the rules that dictate how abberation works.

For example, there is chromatic abberation, spherical abberation, curvature of field, coma, and astigmatism.

All abberations tend to be less toward the center of the image, and become more pronounced as you move toward the edge of the image.

All abberations tend to become less noticable as the focal length increases, and more noticable as the focal length decreases. This is usually given as an f-stop.

The focal length is usually indicated as an "f" number. An example might be an f-8 or an f-10.

The f-stop number usually means the focal length over the diameter of the mirror (or lens), also sometimes defined as the focal length over the aperature (opening) of the telescope. Since most telescopes (there are exceptions) don't have an adjustable opening, the f-stop is defined by the focal length over the mirror (or lens) diameter.

There are hybrid telescopes (called catadioptic) that use both lenses and mirrors.

An example is a Schmidt-Cassegrain telescope, which uses a special kind of lens at the aperature, and a Cassegrain focus telescope for the rest of the instrument.

Become familiar with the Cassegrain focus, Newtonian focus, Prime focus, and off-axis focus. There are other variations like the Gregorian focus, Hershelian focus, and so on . . . but are not as relevant to amatuer astronomers except as a historical intetest.

Catadioptic telescopes manipulate the light path to try and reach various compromises between the different limitations of the different designs.

A good Schmidt-Cassegrain telescope made by Celestron or Meade will provide excellent opportunities for astrophotography, and some come with computer-guided mounts that will precisely track a specific part of the sky (as the Earth rotates), and allow for long time exposures that will show the intricate and exquisite details of galaxies, nebulae, and so on that are invisible to the eye.

Another good design for amature astronomers is the Maksutov-Cassegrain, which uses a different kind of correcting lens at the aperature than a Schmidt-Cass, but still gives stellar (pun intended) results.

Get a subscription to Sky and Telescope, and follow the different things that are happening in the sky. You'll see charts that help you find and identify the 4 large moons of Jupiter, how many Messier objects you can spot at a specific time, and so on.

Some of the places where amatuer astronomers can make scientific contributions include comet hunting (actually best done with large binoculars on tripods) and observing the Moon for different phenomena (sometimes mysterious plumes are reported, which may be from pockets of gas or water), and so on.

Become familiar with the conventions for pinpointing objects in the sky . . . usually given as declination and right ascension. These intimidating-sounding technical terms are actually quite simple to understand, but beyond the scope (did you get the pun?) of a forum post. Look them up in a Google search.

In conclusion, a few safety issues with telescopes need to be brought up.

Observing the Sun requires specialized equipment and training. Trying to observe the sun in any telescope without the know-how and proper equipment may not only damage your instrument . . . but also your eyes. Note that Gallileo discovered sunspots, and lost a lot of his vision in the process.

Also, make sure your telescope is used in context. People have called the police and/or their burly, ape-like biker neighbors with baseball bats to take care of the pervert peeping Tom who likes to look in peoples' windows.

So, invite your neighbors and their children to share your interest in astronomy with pizza and beer (or maybe wine and cheese, or an ice cream party if there are kids). You may make some new friends, inspire young people to science, and--at the same time--avoid a trip to the hospital by sidestepping a dangerous misunderstanding that you're a pervert.
 

sophiecentaur

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What kind of telescope to get depends upon what you want to do, as different telescopes may be good for different goals.
Absolutely and you have given a useful and pretty comprehensive list of facts. Unfortunately, newbies will not know what they actually want to do. The only way to find out that is by using someone else's equipment at least once. Astro societies are usually very happy to arrange to give people a go and show them a thing or two.

Also, you miss out the one important thing for beginners. It is that what they will actually see in a home telescope (whatever you spend on it) will be nothing like the Hubble Pictures in magazines. That simple thing can make a first timer very disappointed. I don't know the size of amateur telescope that will give more than a hint of the colours that Astrophotography will produce.

OTOH, the first glimpse of Jupiter and moons, even in a cheapy scope, could be stunning IFFFFF the viewing conditions are half decent. And the Orion Nebula will be memorable (and easy to find too) :smile:
 
Absolutely and you have given a useful and pretty comprehensive list of facts. Unfortunately, newbies will not know what they actually want to do. The only way to find out that is by using someone else's equipment at least once. Astro societies are usually very happy to arrange to give people a go and show them a thing or two.

Also, you miss out the one important thing for beginners. It is that what they will actually see in a home telescope (whatever you spend on it) will be nothing like the Hubble Pictures in magazines. That simple thing can make a first timer very disappointed. I don't know the size of amateur telescope that will give more than a hint of the colours that Astrophotography will produce.

OTOH, the first glimpse of Jupiter and moons, even in a cheapy scope, could be stunning IFFFFF the viewing conditions are half decent. And the Orion Nebula will be memorable (and easy to find too) :smile:
I agree.

A favorite target for me are the Pleiades. They are beautiful in a small, home telescope and--to me--seem to resemble diamonds spread across black velvet.

Another good target are the stars in the handle of the Big Dipper (Ursa major). There, one can see a binary star in a low-power home telescope.
 

DaveC426913

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OTOH, the first glimpse of Jupiter and moons, even in a cheapy scope, could be stunning
This is what sucked me in.
Went to a local star party, and they had a pair of binocs pointed at Jupiter.
It looked like it was hovering over the buildings! And its moons were right there!
 
This is what sucked me in.
Went to a local star party, and they had a pair of binocs pointed at Jupiter.
It looked like it was hovering over the buildings! And its moons were right there!
I love looking at Jupiter's moons.

There is so much history behind those moons. Galileo was able to use observations of the 4 moons (which he discovered) to help prove that Earth isn't at the center of the Universe.

Also, the first realistic measurement of the speed of light (about 2/3 of the currently accepted value--but only because of faulty measurements of Jupiter's distance from the Earth. The mathematical reasoning was impeccable) came from studying Jupiter's 4 largest moons.

It makes me feel a sense of connectedness with all that history when I look at Jupiter's moons. It's probably silly to feel this way, but I do.
 

sophiecentaur

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I remember reading a short story about a boy who spent nights laying on the roof of his house, looking at the moon. He started to hallucinate that he was looking down at and was falling towards the moon. High magnification through a 'good' scope can make you think in terms of a 'landscape' and the features that you can discern may only be as big as a large city.
PS Never spend long looking at the Moon without a Neutral Density Filter or you will think you have gone blind in one eye when you look away. An ND filter should perhaps be the first filter you ever buy!
 

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