cheap decent telescope

[davecambo (Dave)]

I started a thread about getting a telescope for beginning out, and was given good advise by a few people to get an 8" dob.

HOWEVER, if this is deemed too expensive by my wife for a start out telescope (around 4-500 are the prices on the links on this site for that telescope) is there a telescope for around say the 200 to 300 dollar mark that will allow me to see planet rings and satelites, moons and nebula etc? without being crap, if thats possible. obviously i understand the cheaper you go the more crap they get, but can you get something good enough for a beginner without being too basic to have to upgrade very soon.

thanks again in advance.

dave.

[picklesrules (Nicholas)]

a 6 " dob

[davecambo (Dave)]

seriously? would that be better than most others for that money?

[Blue Skies (Jacquie)]

Yes! Its a bigger aperture than most wobbly plastic refractors (Aperture rules! - in resolution as well as light gathering capability) and the dob will be a much sturdier base. 6" dobs aren't that big, at least I think so. I can tuck the tube under my arm and grab the base in the other - can't do that with my 8".

[picklesrules (Nicholas)]

your best bet is to giver andrews com a call or go there if your near and have a look at the 6" GSO Dobs there a respected brand and for 300 ull probley buy some rubbish 60mm refractor . So best option is the 6" Dob i wish i had found this forum before i bought my first scope id have a 12" dob rite now if i did

[stephenb (Stephen)]

Dave, I agree with all the above. Aperture is the key word. The bigger the mirror or lens, the more "light gathering power" you will have. A GSO 6" Dob from BinTel or Andrews Communications is the way to go, if that's your budget.

[rmcpb (Rob)]

Not so long ago a 6" dob was considered a big scope for a backyard observer. Brands like GSO have changed all that but a 6" is a worthy scope.

Cheers

[davecambo (Dave)]

thanks for the advice! they are more within my range. ill look at getting one in the next few days after speaking to them. i will have to ship it though.

[astro744]

A 6" f8 is an excellent choice that will last a lifetime.

You're only a couple of hours away from Sydney, why not make a day trip out of it and visit a couple of stores or at least the one you intend on buying from. Phone first to make sure they have the 'scope on display too.

Yes the petrol will cost more than the freight but at least you'll see what you are getting and you can bring the 'baby' home yourself.

If you're in no hurry wait for another reason to go to Sydney and make a detour to an astro shop on the way. Bintel are in the city near the fish markets and Andrews is out west off the M7 before the M4.

May I suggest a Telrad when you can afford it (extra $80) as one of your first accessories to give you head up display pointing ability. Don't worry about laser pointers as these are a real problem with aircraft especially if you're under a flight path. A 6" f8 will have a 1.25" focuser so you will never have to worry about expensive 2" eyepieces (unless you upgrade your focuser which will involve some cutting).

Your 6" f8 will either come with a 25mm and 10mm or 9mm eyepiece depending on where you buy. These will give you the following powers and true fields:

f.l. = 1200mm, assuming 50 deg apparent field eyepieces.

25mm gives 48x and 1 deg True Field Of View.
10mm gives 120x and 0.4 deg TFOV.
9mm gives 133x and 0.37 deg TFOV.

For a bit more TFOV you could add a 32mm or 40mm Plossl at a later date if you wish or add a mid power say 12 to 15mm Plossl. I highly recommend the Tele Vue Plossls but the Meade 4000 series Plossls are very well priced and perform very well too.

You can also add a quality 2x or 3x (or both) Barlows that double and triple the power of any eyepiece.

Planets are best bewteen 120x and 200x depending on seeing (sometimes a bit more). A quality 20mm Plossl and 2x & 3x quality Barlow will give you 60x, 120x & 180x which is just about all you need for Planets (120x & 180x) and clusters (60x). Add a 15mm Plossl and you also get 80x, 160x & 240x, (the latter two with the Barlows).

I know it is a lot to think about and more money too but it doesn't all have to happen immediately. Get the 'scope first and just use what comes with it. It doesn't matter what you have as long as you are enjoying it.

[dhumpie]

I agree wholeheartedly with what everyone has said. A 6" f/8 dob will be forgiving on collimation and will give you spectacular views of the planets and resolve some globulars such as Omega Centauri, 47 Tucana, The Ara and Pavo Globs!!!!

Darren

[Bobbyoutback]

If they both don't have a clue about collimation a reflector may not be suitable , maybe start with a 80mm Achromatic refractor

Bobby.

[davecambo (Dave)]

and for around 100 dollars less, what is something like this like

http://cgi.ebay.com.au/Celestron-Ast...item3ca7071fd1

[Bobbyoutback]

Originally Posted by davecambo

and for around 100 dollars less, what is something like this like

http://cgi.ebay.com.au/Celestron-Ast...item3ca7071fd1

Dave thats a horrible joke type scope , someone will give you a link to why its such crap .
Please forgive me for being so heated with my rhetoric .

Cheers Bobby

[bmitchell82 (Brendan)]

i wouldn't suggest a 80mm achro for visual! unless your going to spend some really good dollars aka 600-1k. collmination is not hard it is a little confusing because people are scared that they are going to break something! plus theres more knowledge here on how to collminate a reflector than you could poke a pointy stick at. plus don't worry about any celestron scope untill you get to the bigger ones but in which case your paying 2.5k ...

6" dob and bigger for a beginner will foster your love for the hobby and make it enjoyable for everybody around you! the more aperature you can afford the more you will see and better resolution you will see thats as simple as it gets.!

[rmcpb (Rob)]

Collimation of a 6" f8 only really needs a film canister with a hole in it, easy. The hard part these days is to find the film canister

[davecambo (Dave)]

6" dob it is then!

[bmitchell82 (Brendan)]

Good luck dave just remember to ask any questions you want we are all here to give you a guiding hand!

[barx1963 (Malcolm)]

Good choice! You'll love it, just don't be surprised when you come down with a serious case of aperture fever in a few months!

[PCH (Paul)]

... or weeks .... or days even

[astro744]

Originally Posted by barx1963

Good choice! You'll love it, just don't be surprised when you come down with a serious case of aperture fever in a few months!

If you never look through a bigger 'scope you may not catch that dreaded aperture fever but here are some numbers to tease you.

An object through a 6" is 1.78x brighter at the same magnification to that in a 4.5" (6x6/4.5x4.5).

An object through a 8" is 1.78x brighter at the same magnification to that in a 6" (8x8/6x6).

An object through a 10" is 1.56x brighter at the same magnification to that in a 8" (10x10/8x8).

An object through a 12.5" is 1.56x brighter at the same magnification to that in a 10" (12.5x12.5/10x10).

Note a 12.5" is now rare and 12" is the norm. An object through a 12" is 1.44x brighter at the same magnification to that in a 10" (12x12/10x10).

An object through a 16" is 1.78x brighter at the same magnification to that in a 12" (16x16/12x12).

An object through a 20" is 1.56x brighter at the same magnification to that in a 16" (20x20/16x16).

Note a 6" f8 and 8" f6 are the same length but alas the 8" is $200 more expensive. However the 8" would come standard with a 2" focuser and your maximum true field would increase from 1.3 deg (27mm field stop eyepiece) to 2.2 degrees (46mm field stop eyepiece). 1200mm focal length used in calcs even though it may be closer to 1220mm (48").

There are countless objects withing grasp of the 6" Newtonian and I'm sure you will enjoy hunting them down. Some are easy and bright and others are faint and barely detectable. Quasar 3C 273 is just visible in a 6" given a dark sky, good seeing, good eye sight and a little experience. Pluto too is detectable but very difficult. Omega Centauri is just woinderful as is Eta Carina Nebula and Orion Nebula. Hundreds of galaxies are detectible, some being quite easy once a little experience is gained. The Sombrero and NGC 253 are just beautiful!

The planets too are just beautiful and can be observed in all their glory. Mars is approaching opposition and although not at its closest it will nonetheless exhibit a shrinking polar ice cap and countless dark features rotating almost in sync with the Earth. Mars is the only planet which we can get a good look at its solid surface with Venus being cloud covered, Mercury too small and the others all gas giants. The Moon too is wonderful and you will be hunting down small craters (few km dia) near the Apollo landing sights or just watching the Sun rise on the lunar terminator and see peaks illuminate in very short time or over hours depending on the lunar topography.

Have fun!