ICEINSPACE
Moon Phase
CURRENT MOON
Full Moon 100%
|
|
22-11-2009, 06:23 PM
|
Registered User
|
|
Join Date: Nov 2009
Location: western victoria
Posts: 5
|
|
Zero knowledge needing help
Hello all,
I have only just begun looking into purchasing a telescope for my husband who has indicated he would like one for Xmas. We have NO knowledge at all of telescopes and which one would be the correct one to buy. He will mainly use it for terrestrial use but may in the future be interested in looking to the moon and stars etc. He would not be using it for photography, and would not be needing to transport it, and budget would be up to $400 or so. Viewing will be in small coastal city.
I have some questions, (though i fear they may sound silly).
Would a 80mm be the starter size,
Is it right that this size refers to aperture and bigger is better?
are the ones you buy at department stores hopeless,
is a refractor model better than reflector or are they useful for varying things, and which would we need?
what are these dobs that you all say are great, is this the same as dobsonian, and would we need this type?
If you buy a telescope to look at the stars , what you see is upside down isn't it?, if so, how do you get to view things right side up, for looking at land or out to sea for example? Is there some lens or 'thing' to make it right side up?
Thank you for any help. I may have more questions but i think this will do for a start,
Cheers Jenni
|
22-11-2009, 07:02 PM
|
|
Registered User
|
|
Join Date: Feb 2005
Location: Launceston Tasmania
Posts: 9,019
|
|
Jenni, I would buy an 8 inch Dobsonian. You should find one for close to your $400 target.
They're easy to use, and with a reasonable aperture they will perform very well.
Astro scopes aren't that useful for terrestrial, they are usually too powerful, better off with a cheap pair of binoculars for that.
Bintel or York Optical in Melbourne would be good places to start, their prices are good and service is excellent. York optical also offers discounts to IIS members.
|
22-11-2009, 07:04 PM
|
|
Registered User
|
|
Join Date: Feb 2007
Location: Perth WA
Posts: 2,297
|
|
Quote:
Originally Posted by 726jenni
Hello all,
I have only just begun looking into purchasing a telescope for my husband who has indicated he would like one for Xmas. We have NO knowledge at all of telescopes and which one would be the correct one to buy. He will mainly use it for terrestrial use but may in the future be interested in looking to the moon and stars etc. He would not be using it for photography, and would not be needing to transport it, and budget would be up to $400 or so. Viewing will be in small coastal city.
I have some questions, (though i fear they may sound silly).
Would a 80mm be the starter size,
Is it right that this size refers to aperture and bigger is better?
are the ones you buy at department stores hopeless,
is a refractor model better than reflector or are they useful for varying things, and which would we need?
what are these dobs that you all say are great, is this the same as dobsonian, and would we need this type?
If you buy a telescope to look at the stars , what you see is upside down isn't it?, if so, how do you get to view things right side up, for looking at land or out to sea for example? Is there some lens or 'thing' to make it right side up?
Thank you for any help. I may have more questions but i think this will do for a start,
Cheers Jenni
|
Wow Jenni ,
such a lot of questions. to IIS
Main use land observing, - 80mm is ok (binocs would be better !)
The 80mm does indeed refer to the aperture of the main lens (front of a refractor, but rear of a reflector). Size is everything here since you're trying to capture as much light as possible.
Department store scopes, bypass, - yes they are hopeless.
Refractor and reflector - both have their uses, but we all have to start somewhere. When you start, you want to see as much as possible. This means, by inference, that you want as big an aperture as possible. This means by inference that a dob is the way to go !
A dob (its a reflector mounted on a dobsonian mount) is a great thing to buy for astronomy, since you are getting a lot of aperture for your money. The mount is very simple, so you aren't paying much for that. This means most of your moey goes into the optics, which is good. You'll get a 6" dob for $400 ish. Look at www.bintelshop.com.au and search on dob.
Astronomical scopes do see things upside down and left to right swapped too. But it doesn't matter. A land scope will have what's called an erecting eyepiece included. If you buy and astronomical scope and want to look at terrestrial stuff, you will have to buy one of these separately.
Hope that answers your questions Jenni
Cheers
|
22-11-2009, 07:25 PM
|
|
Retired, damn no pension
|
|
Join Date: Nov 2004
Location: Obi Obi, Qld
Posts: 18,778
|
|
Well I'm going to go against the grain here. If the predominant use is terrestrial viewing then a dob it going to be very awkward for looking at birds and other interesting things in a beach scene. Also they are not really what one would call "grab and go". My suggestion would be for an 80mm refractor with erecting eyepiece on an Alt/Az mount. Very portable and still giving very useful views of the heavens.
Skywatcher 102 x 500 AZ3 on this page fits the bill, but the mount may be a bit of an issue in its stability.
Or this would be my pick on this site. SkyWatcher 80mm Refractor AZ4 mount
Refractors suitable for terrestrial use (need erecting eyepiece for some)
|
22-11-2009, 07:52 PM
|
Registered User
|
|
Join Date: Nov 2009
Location: western victoria
Posts: 5
|
|
Thanks to you all for info,
Could someone tell me the difference between AZ3 and AZ4 mount please
Jenni
|
22-11-2009, 08:10 PM
|
|
Retired, damn no pension
|
|
Join Date: Nov 2004
Location: Obi Obi, Qld
Posts: 18,778
|
|
Basically the AZ4 will carry a bigger scope and will most likely be more stable. Other than that they operate the same way, up and down, left and right. If you are checking out other scopes on the site you will come across equatorial mounts. Not really recommended for Terrestrial viewing. They are designed for astronomy
|
22-11-2009, 08:40 PM
|
Registered User
|
|
Join Date: Nov 2009
Location: western victoria
Posts: 5
|
|
Thanks Paul, that sorts that out.
jenni
|
22-11-2009, 10:09 PM
|
Registered User
|
|
Join Date: Nov 2009
Location: Perth
Posts: 26
|
|
I managed to pick up a second hand but mint cond 8" dob a couple of weeks ago from these forums for $400.00 so you should be able to get something similar
|
23-11-2009, 03:45 PM
|
|
1¼" ñì®våñá
|
|
Join Date: Nov 2006
Location: Sydney
Posts: 1,845
|
|
Quote:
Originally Posted by 726jenni
Would a 80mm be the starter size,
|
80mm aperture is a good starter size. The first scope I bought for my dad was an 80mm achromat refractor, and my first scope was 90mm. While you won't be out there hunting faint galaxies, you will still have a plethora of targets to explore on your starting journey into the night sky.
Quote:
Is it right that this size refers to aperture and bigger is better?
|
yes, correct. With astronomy, we don't use telescopes for their magnification, we use telescopes because they capture alot of light, and astronomy targets are generally very dim, so more aperture, the more things you can see with a telescope.
Quote:
are the ones you buy at department stores hopeless,
|
in a simple word, yes
Quote:
is a refractor model better than reflector or are they useful for varying things, and which would we need?
|
They are useful for varying things. For your needs, which include both terrestrial and astronomy, I would suggest a refractor.
Quote:
what are these dobs that you all say are great, is this the same as dobsonian, and would we need this type?
|
a dob is a short name for a dobsonian. Dobsonian is actually the name for the mount type. The dobsonian telescope is a reflecting (mirror) telescope on a simple push/pull mount type which sits on the ground. The advantage of a dob is that you spend little on the mount, and more on the optics. It allows you to get large aperture for a low price. If your husband was wanting a telescope for astronomy only, with no terrestrial, I would suggest a dob.
Quote:
If you buy a telescope to look at the stars , what you see is upside down isn't it?, if so, how do you get to view things right side up, for looking at land or out to sea for example? Is there some lens or 'thing' to make it right side up?
|
for a refractor you can use a 45 degree prism which will give you the correctly oriented view for terrestrial. For astronomy (when you are viewing things up high) a 90 degree mirror diagonal is better.
|
23-11-2009, 05:36 PM
|
|
daniel
|
|
Join Date: Sep 2007
Location: Macedon shire, Australia
Posts: 3,426
|
|
can i go agaonst most of the posts here and suggest if terrestrial is to be the main use then an upright & correct image will be of high importance..i think there are two good options
1. high powered binos, something like 15x70 or 20x80
2. a spotting scope, goto andrews http://www.andrewscom.com.au/site-section-10.htm then the long perng section.. they have a 80mm spotting scope which is waterproof & has adjustable zoom.
the only thing left to do in either case is get a decent tripod, andrews have generic chinese ones which are pretty good - stick with a known brand as cheap ones will falll over / wobble
|
23-11-2009, 09:53 PM
|
Registered User
|
|
Join Date: Nov 2009
Location: western victoria
Posts: 5
|
|
Thank you all
there is so much knowledge out there and i appreciate the time you have taken to help me. it's invaluable
another question or two
do we need a zoom to look at land objects. do you use zoom to look at the night sky?
re the thing that we need to buy so objects can be seen up the right way, (can't remember what it's called) what do we ask for and are there different types and how much will it cost, will we be able to install it?
cheers
jenni
|
23-11-2009, 10:50 PM
|
|
1¼" ñì®våñá
|
|
Join Date: Nov 2006
Location: Sydney
Posts: 1,845
|
|
Quote:
Originally Posted by 726jenni
Thank you all
there is so much knowledge out there and i appreciate the time you have taken to help me. it's invaluable
another question or two
do we need a zoom to look at land objects. do you use zoom to look at the night sky?
re the thing that we need to buy so objects can be seen up the right way, (can't remember what it's called) what do we ask for and are there different types and how much will it cost, will we be able to install it?
cheers
jenni
|
With telescopes you change magnification by changing the eyepiece. All telescopes have eyepieces that you can change (only cheap toy ones don't). An eyepiece with a 10mm focal length will give twice as much magnification as one with 20mm. You can get zoom eyepieces as well if you like.
A 45 degree correct image diagonal will set you back about $50. This is what they look like: https://www.bintelshop.com.au/Product.aspx?ID=6338
|
24-11-2009, 06:06 PM
|
Registered User
|
|
Join Date: Nov 2009
Location: western victoria
Posts: 5
|
|
thanks, great info.
we are now planning a trip down to melb to bintel store armed with at least a basic amount of info.
jenni
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT +10. The time is now 01:46 PM.
|
|