I want to buy a telescope, but I'm clueless...

[ferrari_chris]

I'm looking to buy a telescope in the near future, but I have no idea about anything to do with them.

Well, I have two ideas so far.

Firstly, I want to look at stars in the sky rather than ships in the ocean, so I think I need a short, fat style telescope rather than a long thin one.

And secondly, I think that basically 'the bigger, the better' rule applies. I think that the larger apeture it has (6inch vs. 8inch) the further it can see and the better it will be? Also, I think the apeture rating (size?) is the same as the diameter of the internal mirror?

If you know some things about telescopes, and what makes a good one and a poor one, can you correct me if I'm wrong above and leave some good points for me to check when looking to buy one in the next few weeks?

For example, is something like this likely to be any good for an entry level, or is it just a piece of plastic junk?: http://www.trademe.co.nz/Electronic...s-telescopes/Telescopes/auction-139241500.htm This is around the budget I have.

Thanks for any help and advice. I don't think I've ever bought something that I have so little idea about before.

 

[Famine]

Looks quite like mine...

Go for it.

 

[Alfaholic]

I don't know much about them, except that the short fat ones with a mirror at one end and the viewing lens on the side are reflector telescopes, and long tubular ones where you look in one end of the tube and point the other end are refractors. Refractors are better for looking at things on Earth, reflectors are better for looking at things in space. I can't give you much more clue except the quality of the mirror is important, and the magnification has a lot to do with the viewing lenses you select, so budget for a nice, good quality collection of those too. Also a moon filter is handy if you plan on studying the moon (which looks amazing!!!)

 

[Wenders]

We have a telescope, we rarely use it. My dad brought it with him when he came to visit once and left it here. Used to be able to connect it to the computer but I lost the software on a reformat. Can't remember the specs, something like 1.5m focal length.
My Dad is right into them, he even has an observatory in his backyard.

He has a bit on info about telescopes on his website that may help you. He has also done a lot of work on some computer planetarium program called Stellrium.

 

[TB]

He has also done a lot of work on some computer planetarium program called Stellrium.

Stellarium is an outstanding piece of software to know what exactly it is you're looking at. Thank him for me. :tup:

I purchased a reflector telescope a few years ago and had to bring it back. If I was outside in anything more than a few mph wind, my mirror bounced around so much I couldn't see anything. If you're going to keep it inside and use it through a window, or at least sheltered, it should do just fine.

 

[Azuremen]

I used a reflector for years with no issues. TB, your wind story just sounds like the mirror and tripod wasn't very secure...

Reflectors are ideal for novices and intermediates. They are the cheapest for the aperture you can get, but they do have some draw back. First is at high levels of magnification, you will notice the eye-piece mirror casts a shadow... though this is rarely noticeable unless you have the main mirror a little off. The other major issues is dust - since the end is open, dust can collect on the mirror over time with use. Cleaning the mirror is a big hassle, so always keep the telescope cap on when not in use.

When buying, try to get the largest aperture you can afford, unless the weight/size of the array would make it difficult for you transport. The gains of doubling the aperture are 4 times more light to work with for each doubling of it... so a 4 inch will get 4 times as much light as a 2 inch, and an 8 inch will get 4 times as much light as the 4 inch and 16 times as much as the 2 inch. More light means the brighter the image and the greater magnification lens you can use.

Computer guided telescopes are neat, but I feel part of the fun is finding stuff on your own. Pick up a good book for star charts and find a place to see magnitude 5 stars (the dimmest that people can see with the naked eye). Viewing near any major population is horrible due to light pollution, though at the same time it can be helpful if you are just looking for major constellations.

You do have some neat thing to observe, being so far south. Stuff I've only gotten to see on my trip to the cook islands... all the good stuff is in the southern hemisphere, except for maybe the Pleides. And Andromeda... the southern cross is wonderful, and so it the black area.

 

[ferrari_chris]

Looks quite like mine...

Go for it.

Yeah, they do look pretty similar. You're happy with the performance of your one? Any problems with it?

... I can't give you much more clue except the quality of the mirror is important, and the magnification has a lot to do with the viewing lenses you select, so budget for a nice, good quality collection of those too. ...

Are there any numbers or specifications I can look for that sets a good quality mirror apart from a poor quality one? And is it the viewing lens that gives the maginfication (which I'm assuming is the scope [think gun] like piece that you actually look into) rather than the telescope itself?

... Can't remember the specs, something like 1.5m focal length. ...

Is that awesome, about average or towards the lower end of things?

Stellarium is an outstanding piece of software to know what exactly it is you're looking at. ...

It looks awesome! I'm downloading it right now. Thanks.

... I purchased a reflector telescope a few years ago and had to bring it back. If I was outside in anything more than a few mph wind, my mirror bounced around so much I couldn't see anything. If you're going to keep it inside and use it through a window, or at least sheltered, it should do just fine.

Is this a common problem?

... First is at high levels of magnification, you will notice the eye-piece mirror casts a shadow... though this is rarely noticeable unless you have the main mirror a little off. ...

Is the main mirror hard to adjust to the precision level needed? And does it need adjustment constantly?

... When buying, try to get the largest aperture you can afford, unless the weight/size of the array would make it difficult for you transport. The gains of doubling the aperture are 4 times more light to work with for each doubling of it ... More light means the brighter the image and the greater magnification lens you can use.

Excellent. Thank you.

... Computer guided telescopes are neat, but I feel part of the fun is finding stuff on your own. Pick up a good book for star charts and find a place to see magnitude 5 stars (the dimmest that people can see with the naked eye). Viewing near any major population is horrible due to light pollution, though at the same time it can be helpful if you are just looking for major constellations. ...

I think tracking down what I want to view will be the third challenge, after actually buying a telescope I want, then setting it up. I can get to unpolluted sky (light or smog) within a short drive of my house, so that's covered.

Thanks everyone for your help so far. Keep the advice coming please. 👍

 

[Alfaholic]

Are there any numbers or specifications I can look for that sets a good quality mirror apart from a poor quality one? And is it the viewing lens that gives the maginfication (which I'm assuming is the scope [think gun] like piece that you actually look into) rather than the telescope itself?

Can't help you with specs, don't know enough about them. I believe the metal coating on the mirror is important, but can't remember what to look for I haven't acquired one since I was a teenager, which was a long, long time ago. I think my reflector, which was 4.5in or 5.5in or something, had an aluminium coated mirror or something. It was susceptible to corrosion apparently, and whatever it was, it was a cheap mirror, though I must say I used the scope for many years and it still picked out the cloud bands around Saturn, never mind the rings and moons, with beautiful clarity 15 years after I got it.

The lens fits into a small tube that sticks out of the side of the telescope, at right angles to the bigger tube. So if you were using the scope to look north, for instance, the big tube would be pointing north, at whatever you're looking at, but you yourself would be facing east or west. The scope I think you are referring to, which runs parallel to the main tube, is a sighting scope. You use this to align the telescope only.

If you don't get the answers you need here, then perhaps it's best to browse some telescope of astronomer forums to get a better feel for lens magnifications and quality, and what mirrors are best, and so on.

 

[ferrari_chris]

...

The lens fits into a small tube that sticks out of the side of the telescope, at right angles to the bigger tube. So if you were using the scope to look north, for instance, the big tube would be pointing north, at whatever you're looking at, but you yourself would be facing east or west. The scope I think you are referring to, which runs parallel to the main tube, is a sighting scope. You use this to align the telescope only.

If you don't get the answers you need here, then perhaps it's best to browse some telescope of astronomer forums to get a better feel for lens magnifications and quality, and what mirrors are best, and so on.

Thanks for that.

And I'm getting some questions and stuff together before I go an pester the dude at the camera shop later in the week (they sell telescopes too).

 

[ferrari_chris]

OK, so I went to the shop in town and chatted to the guy. Nice man he was too.

I think I'm going to go with this model:

http://www.tasco.com.au/Default.aspx?tabid=82&ProductID=1367&cid=209

Hopefully it's in my price range - I'm going to see him on Monday to get prices.

Now, this telescope comes with a 225x lens. I asked the guy what this will let me see - will I be able to see the rings of Saturn and the Jupiter spot? He answered: "That's a good question..."

So, does anyone here know about what magnification will let me see what? I have a better understanding about what makes a good telescope and important things to look for now, so that's good. Also, I learnt that reflector telescopes (which this is) display an image that is mirrored and inverted.

I think I'm off to find other Internet people knowledgeable on such matters.

 

[Alfaholic]

I dunno. It comes with three lenses and 3 Barlow lenses (which if I remember double the magnification but at the expense of focus). The most powerful lense is the 225x, and 4mm. I don't know what magnification I had but I am pretty sure that my best lens was a 6mm, and that was good enough to show me the cloud bands (and red spot) on Jupiter, and the rings and bands of Saturn. You can see Jupiter's major moons with binoculars so I am pretty sure that most telescopes will pick them out easily, but they will just look like small stars so don't get too excited about them. I would double check the lens with someone who knows better, but I'm 90% sure you're good to go with that one.

This one comes with a moon filter too, which is nice, as the moon is pretty bright, esp. through a telescope. It sounds like a good package to me....

You won't notice that the image is inverted until you a) fine tune the alignment while observing some object and notice that the image scoots off in the opposite direction to what you expected, or b) you use it to look at something on Earth.

 

[ferrari_chris]

...

You won't notice that the image is inverted until you a) fine tune the alignment while observing some object and notice that the image scoots off in the opposite direction to what you expected, or b) you use it to look at something on Earth.

Yeah, that's cool. It doesn't bother me, not that I could do anything about it anyway.

From another forum I asked on, I got these tidbits of advice:



About whether I could see the rings of Saturn:

I started with a meade 6 inch newtonian. It was great for the moon and I could make out the planets but could not see the rings of saturn. I recently purchased a 12 inch meade light bridge with a focal length of 1524mm. It came with a 26mm wide angle lens, but I still could not make out the rings. I have sinced purchased a 2x barlow and a 15mm lens and now I can see the rings, it even shows me the dark spaces between the rings and the planet. I am not familar with the model you are considering. I was at 119.4 magnification before I saw the rings.

On my choice in general:

I did a brief Google search for the scope you are planning to buy and came up with a price of about $380? For that price, in my opinion, you can get a telescope with much better optics and better build quality than the Tasco. Check out offerings from Celestron, Meade, Orion, and Zhumell in the same price range before you commit. Maximum magnification possible for a 4 inch scope, under perfect sky conditions (which is rare), will be between 225x and 270x. So the 4mm eyepiece will only be useable on rare occasions, and the 3x barlow that comes with the scope will only be useable with the 25mm eyepiece. The mount shown in the photo of the scope looks very light which could cause a problem with holding the views steady.

Does this sound accurate?

 

[ferrari_chris]

After some more opinions from the Internet, and reading some reviews I've decided to put my telescope purchase on hold.

The more I read the more I realise it's intensely complicated and I have no clue what I'm doing.

I think I'm going to head to my local observatory when I get a chance and have a chat to the people there, and try and get to a local astronomy club meeting and 'try out' some telescopes.

I'm just frustrated by the whole thing really.

 

[Azuremen]

Probably for the best, at the moment.

Pick up a book on astronomy and get some okay binoculars. You'll be able to familar yourself with the sky a bit and still see some neat things with the binoculars.

 

[ferrari_chris]

I think I'll need a tripod with binoculars though, no? I've tried simple binoculars vs. the moon before and my shaky hands got a white streak, at best.

 

[Azuremen]

Try leaning against something then. Its amazing how much just leaning on something can help I've found.

 

[Touring Mars]

Just did a search and found this thread....

Did you get anywhere with your fledgling hobby, Chris?

I am toying with the idea of getting a telescope, too, but am in the same position as you (except I have the added complication of living in Scotland, where the night sky is usually obscured by clouds!)...

I was thinking about building my own, but that is probably stupid, given that a) decent lenses/optics are likely to set me back alot more than a decent amateur telescope would anyway, and b) I'm technically inept and c) I'm lazy as anything...

Similar to you, I'd like to have a go with a decent telescope first before deciding how much to invest in one (esp. given the frequency of use I'd get out of one...), but I am a tad reluctant to get involved with a club or a society, since all I want to do really is fart around...

Having a bit of disposable cash these days, I'd be willing to consider a telescope up to about £400, but haven't really got a clue for what to go for... but with winter approaching, it is a good time here in Scotland for long, dark nights!

edit: BTW, Azuremen's advice about leaning on something is bang on the money! Also, I currently use a monocular, as opposed to binoculars, which is far easier to hold still, and is also easier to use generally since using one eye instead of two is much better for focusing on hard to see objects... even with my we monocular, I can just about resolve a moon or two of Jupiter, although I only know it's Jupiter from it's location in the sky, and cannot make out any detail of the planet itself...

 

[ferrari_chris]

I abandoned the idea before parting with any money for two reasons:

The higher quality the telelscope is, the harder it is to set up. I recall reading that even when set up, some telescopes will need be readjusted as the night wears on. This is an extremely delicate process too.

And secondly: I don't know anything about the night sky, and initally was keen to just look at whatever I could see - however tracking down interesting objects by name/location was like learning a foreign language. Most stars are referenced by other stars, and if you can't find the 'landmark', there's little hope of finding what you're looking for.

At the end of my investigations it all seemed too technical for me to have the sort of fun I wanted to have, so I abandoned the idea at the research phase.

For you I'd recommend:

Find a club and attend a night they'll have (all astronomy clubs have gatherings, etc.) and looking through their telescopes and talking to the people about their experiences, etc.

Buy a cheaper telescope to get you started - I imagine you could pick up a decent starter for less than the $UK400 you mentioned.

Learning about the night sky so you understand the terminology and can locate important stars with your bare eyes - that will make tracking down other stars/comets/planets possible.

Let me know how you get on.

 

[Touring Mars]

I abandoned the idea before parting with any money for two reasons:

The higher quality the telelscope is, the harder it is to set up. I recall reading that even when set up, some telescopes will need be readjusted as the night wears on. This is an extremely delicate process too.

And secondly: I don't know anything about the night sky, and initally was keen to just look at whatever I could see - however tracking down interesting objects by name/location was like learning a foreign language. Most stars are referenced by other stars, and if you can't find the 'landmark', there's little hope of finding what you're looking for.

At the end of my investigations it all seemed too technical for me to have the sort of fun I wanted to have, so I abandoned the idea at the research phase.

That's a shame, but maybe it's something you'll do later - like myself, I gave up on the idea of forking out alot of cash on a telescope some years ago, but now my circumstances have changed and it makes alot more sense to buy something now... ironically, I have found that these PC apps (which are amazing) leave me somewhat underwhelmed... I really want to be able to see these things for real!

Saying that, I have to remind myself that I need to start somewhere and not get my usual "big ideas" - ideally, I'd like to have something like Wenders posted above (that would be so great ) but a) I am not that practically inclined and b) I don't even own my own house, let alone have somewhere to make an observatory (unless I can persuade my sister to let me break a hole in the roof of her house 💡 )

For you I'd recommend:

Find a club and attend a night they'll have (all astronomy clubs have gatherings, etc.) and looking through their telescopes and talking to the people about their experiences, etc.

I think this is the best thing to do 👍 Although I am quite like you in the regard that I really want to be able to do stuff in my own time, and for fun rather than taking it too seriously, and a field-full of geeky astronomers sounds a bit... well, I shouldn't knock it until I've tried it I suppose!!

Learning about the night sky so you understand the terminology and can locate important stars with your bare eyes - that will make tracking down other stars/comets/planets possible.

I have a good head-start on this, since I've always been interested in the night sky and know my way about pretty well. I have a couple of small but excellent guide books (Collins Gem "The Night Sky" is perfect) and I also had this , which is very handy (albeit a bit out-dated, but it saves you from taking a laptop out into the garden!)

Let me know how you get on.

Will do 👍

 

[Touring Mars]

Got my telescope today and assembled it here at work, and have just spent about an hour trying to figure out how to use it! Without properly setting it up, it took me the best part of half an hour just to be able to see Venus, which given that it's the brightest object in the sky right now is pretty lame! However I managed it eventually and could see the crescent of the disc pretty clearly. I've got a 6" reflector, so wasn't expecting it to be too great, but a promising start nevertheless...

... my top floor vantage point here at work gives me a pretty good view of the sky, but it is going to be too bright to do anything too serious unfortunately. The night skies are alot darker out at my Mum's place in Edinburgh, so I think it might need to journey east soon, but I think the only way I will get really good viewing done with it is out in the country.

Anyway, it set me back £200 and I'm starting to see why people fork out for the 'extras' that I didn't think I would need - but for a starter scope, I'm pretty happy with it already 👍

 

[ferrari_chris]

Good to hear you got it working.

As you've no doubt figured out they can be quite tricky to set up, but from what I understand, once they're set up even a 6inch can be quite powerful.

Enjoy.

 

[Touring Mars]

I got my first look at Saturn at the weekend

I got the sharpest view through the normal lens (about x50 magnification, I think) and the disc of the planet appeared about this size: --> At this mag, the rings look like a straight line through the disc, making the whole thing about the length of my thumbnail... I could also see what looked like about 4 moons, although I couldn't say for sure that they were all Saturn's moons and not faint stars in the background...

So far, I'm only getting to use the telescope every now and then - i.e. when I am staying at my Mum's house and when the skies are clear, in other words, approximately once every 4-6 weeks I'm pretty limited to the length of time I can use it as well, and so far have only had about 6-8 hours of viewing time in total, but I already feel like I have had "good use" out of it, with plenty more to come hopefully... I'm happy with the price tag of just over £200 for this level of use though...

Next stop, Jupiter... am about to check where (and when) I can expect to see it... it should look alot bigger using the same mag, since it is physically larger than Saturn, and twice as close (only 700 million km away!!)

 

[Sureboss]

Should be easier once summer starts, which for Glasgow is for about 3 days in August!

 

[Famine]

What lenses do you have for it?

I'm looking to get some more lenses for mine as when I was looking at Jupiter all I could see was a pinky-orange smear the size of a gnat's chuff.

 

[Touring Mars]

What lenses do you have for it?

I'm looking to get some more lenses for mine as when I was looking at Jupiter all I could see was a pinky-orange smear the size of a gnat's chuff.

I've got two eyepieces, 25 mm and 10 mm eyepieces, and a 2x Barlow to double the mag of either eyepiece. (I'm also using a 6" reflector)

I haven't worked it out yet, but the 10 mm lens (higher mag) should give me a mag of about x75 - increasing to x150 with the Barlow... however, the Barlow makes it slightly blurred and increases the chromatic aberration (producing a blurry, coloured edge). Without the Barlow the object is smaller but much sharper...

It sounds odd that you are seeing a small, blurred object... I'd maybe expect to see something similar if I used the 25 mm (lower mag) eyepiece with a Barlow, but I could still see Saturn clearly even with the lower mag eyepiece, and without the Barlow (i.e. the lowest possible mag I can use, which is about x30 I think)..

 

[ferrari_chris]

Good to hear you're having the experiences I wanted to have.

Keep it up mate.

Now you just need to figure out to hook your camera up to it to get some snaps.

 

[Touring Mars]

Good to hear you're having the experiences I wanted to have.

Keep it up mate.

👍

Now you just need to figure out to hook your camera up to it to get some snaps.

I was thinking about that, but there is one major problem (aside from my inability to operate my digital camera!) and that is that you'd need a telescope with a motorized tripod to be able to take long exposures of objects through a telescope... Due to the Earth's rotation, objects viewed through a static telescope appear to move - the higher the magnification you use, the worse the problem is... Using the highest magnification I have, objects appear to be constantly moving and cross the whole field of view in under 30 seconds! This means that I'd have to manually track the object precisely (which is practically impossible) for even short exposure times, otherwise I'd get a blurry streak instead of a sharp image... it's not so much a problem when just looking through the scope, because it is relatively easy to keep an object within the field of view and your brain isn't too fussy about small changes in position, but it makes all the difference if you want to take a photo.

That said, I'd like to try some photography using low magnifications and see what I can get - it would help if I knew the first thing about my camera though

edit: By the way, I recommend this piece of free software: http://www.hnsky.org/software.htm It's really easy to use and has alot of very useful features - I just discovered a tool that shows you how dark the night sky is going to be in your location for the next 2 months... sadly for me, the window of dark sky is getting smaller and smaller

 

[Famine]

I've got two eyepieces, 25 mm and 10 mm eyepieces, and a 2x Barlow to double the mag of either eyepiece. (I'm also using a 6" reflector)

I haven't worked it out yet, but the 10 mm lens (higher mag) should give me a mag of about x75 - increasing to x150 with the Barlow... however, the Barlow makes it slightly blurred and increases the chromatic aberration (producing a blurry, coloured edge). Without the Barlow the object is smaller but much sharper...

It sounds odd that you are seeing a small, blurred object... I'd maybe expect to see something similar if I used the 25 mm (lower mag) eyepiece with a Barlow, but I could still see Saturn clearly even with the lower mag eyepiece, and without the Barlow (i.e. the lowest possible mag I can use, which is about x30 I think)..

My lenses are marked "Super10" and "Super25" (and 2x Barlow). What magnification this corresponds to... I know not.

 

[Touring Mars]

You've got the same as me... apparently, to find out the magnification each will produce, simply divide the focal length of your scope (in my case, 1200mm) by the focal length of the eyepiece... so in my case, the 10 mm eyepiece gives me 120x magnification (240x with the 2x Barlow) and the 25 mm eyepiece gives 48x magnification (96x with the 2x Barlow)

[/calculator]

 

[ferrari_chris]

... Due to the Earth's rotation, objects viewed through a static telescope appear to move - the higher the magnification you use, the worse the problem is... Using the highest magnification I have, objects appear to be constantly moving and cross the whole field of view in under 30 seconds! ...

Wow. I had no idea the "viewing window" would be so short.

And I now totally understand the issue with taking photos.