im considering upgrading my telescope, but i don't know whether to go for large aperature or portabillity. i often go camping in places with very dark skies, infact i spend most weekends on a large property in central victoria.
i was thinking of a bintel 10" dobsonian to take advantage of the dark skies, but it will be a little harder to transport (we ussually travel with a trailer or caravan, but would that be a safe place for a telescope at 100kmh ?)
i currently own a 127mm EQ reflector of very low quility, so i started by just looking for a good quality replacement (125/130mm), but since a good replacement will cost around $600-$700, i thought it would be better to buy a dobsonian or something, but i really can't decide.
i can spend up to $700, but less would be better. i live in geelong, so any recomendations would need to be available in melbourne.
I was stuck with the same dilema, and decided after consideration how often I would get the oportunity to travel with my setup, as opposed to how often I would use it and not have to travel, I went the whole hog on a permenant set up mainly because I live a million miles from anywhere that is ever likely to have a gathering requiring portability. In your case you have dark skies where you are, "no need to travel" Go with the big Dob,,, My 2 cents...
I agree with Rob... go the dob. You will work out how the transport it, either across the backseat of the car, or on the bed in the van. You won't regret the extra aperture.
Location: Tucson, before that Wisconsin, before...
Posts: 231
power or portability?
I'll add another vote for the dob. A bintel (GSO) dob is fairly robust, and riding on cushion in a caravan would be fine. This gives you clearly the most bang for the buck in terms of seeing whats up there.
Did you know about the "dob night" event at macedon ranges observatory this saturday night? I've never been there and am new to the country, but could be a way to inspect several different brands up close and personal and test drive some...Last I heard (20 min ago via email) they had openings. http://www.darksky.net.au/
Scott
Quote:
Originally Posted by Jarrod
hi everyone,
im considering upgrading my telescope, but i don't know whether to go for large aperature or portabillity. i often go camping in places with very dark skies, infact i spend most weekends on a large property in central victoria.
i was thinking of a bintel 10" dobsonian to take advantage of the dark skies, but it will be a little harder to transport (we ussually travel with a trailer or caravan, but would that be a safe place for a telescope at 100kmh ?)
i currently own a 127mm EQ reflector of very low quility, so i started by just looking for a good quality replacement (125/130mm), but since a good replacement will cost around $600-$700, i thought it would be better to buy a dobsonian or something, but i really can't decide.
i can spend up to $700, but less would be better. i live in geelong, so any recomendations would need to be available in melbourne.
i think i'll go for the dobsonian. i won't be able to get to the macedon ranges observatory this weekend, but i'll proberly go to the astro' society in geelong.
i thought it might be worth getting (or making) a second mount, one to leave up at the farm (central vic) and one to have at home (geelong). that way i would just have to transport the OTA.
thanks, jarrod.
BTW, when i said in the thread "caravan or trailer", i really meant one or the other. we have a trailer that we use just to take stuff up to the farm (we have a house up there to stay in, so no need for a caravan). we use the caravan (the type with a fold-down top section) to go camping.
after seeing some dobs at the geelong astro society, ive now got i real sense of how big these things are (they look smaller in pics!!). after some looking around the internet i thought it might be easier to go for something more portable then the 10" GSO, and thought maybe an 8" or 10" meade lightbridge. id still like a 10" scope, but $1100 is a bit more then $700 . the 8" is more toward my price range at $900.
so i need peoples opinions on the views through an 8" compared to a 10", i know the view through a 10" would be far better, but would an 8" still give a nice view? i could proberly manage to pay for the 10", but id have less money left over for other bits n' pieces like extra eyepieces.
thanks, jarrod.
BTW, i know someone will ask this, so i'll say know: i would like too be able to see lots of bright and dim DSO. also planets, and the moon, but id rather have a go at viewing (and trying to find) DSO. so the light gathering power is a very important factor.
The 8 inch is a nice size but the 10 inch will see "more" (fainter/detail) because it has a bigger mirror...So if it is faint fuzzies that you want to see get the biggest aperture that you can afford.
I am not sure that I see the advantage of an 8 inch truss dob (like the Lightbridge). space for mirror box/base truss poles and secondary I don't think the foot print would be that much smaller...it might be a better utilizer of space though.
If I was going to go with 8 inches for budget reasons the GSO is hard to pass up in my opinion.
I started with an 8 inch GSO and still use it...it is a nice all around scope for the money. You will be able to spend a life time finding new things even with an 8 inch. Heck, 10- 15 years ago an 8 inch scope would have been considered "big" by many.
The 8 inch is a nice size but the 10 inch will see "more" (fainter/detail) because it has a bigger mirror...So if it is faint fuzzies that you want to see get the biggest aperture that you can afford.
I am not sure that I see the advantage of an 8 inch truss dob (like the Lightbridge). space for mirror box/base truss poles and secondary I don't think the foot print would be that much smaller...it might be a better utilizer of space though...
your right about the size differance of the 8" and 10" lightbridges, they are on almost the same sized mount!
i was actually going to go for the 10" bintel (GSO) dob at first. the 8" sounds like a nice scope, but the portabilty of a truss tube dob means i'll proberly travel with it more. i thought it would be worth paying a bit more for the extra use i'll get out of it.
i was just on the bintel site and the lightbridges have gone on special, the 10" is now $950 . (although the 8" is now only $800).
one concern i have with the lightbridge is collimation: will it be way out of collimation every time i re-assemble it? i read that the lightbridges are pretty good at staying collimated if they are re-assembled with the support poles arranged in the same order every time.
thanks, jarrod.
Last edited by Jarrod; 20-06-2007 at 07:48 PM.
Reason: correcting names
Jarrod, the Lightbridge, along with any truss type, will require a re-collimation after setting up. Nature of the beast.
Just buy a combination Cheshire. You may find it advantageous at a later date, to buy a laser collimator & using it with a Barlow to collimate a truss type.
For your question re; which 'size' will see more, fainter objects, see my first response but see also > http://www.twcac.org/Tutorials/limit...tude_table.htm
& you'll see that there's only 'bout 1 Mag between your 'scopes of choice'. (eg; 8" n 10").
It all comes down to price, storage, portability etc etc.
It's your choice.
HTH. L.
Location: Tucson, before that Wisconsin, before...
Posts: 231
Dobification Pontifications
That's a great price for a 10" LB. My 12" GSO dob was $899 on sale at the time. Don't know why it was, and why it's more now on the website...maybe was a MEL-based rationale to move stock. I'd bet if you talked to the right person, you could maybe talk them down a bit on their posted price on the GSO scopes...
But the LB is a splendid scope and yes, that truss design sure has it's benefits in terms of packing away nice. Then again, for a 12", which I can handle and fit in my car, I like the solid tube MORE, because it takes less time to set up. For a ripped and muscular bloke like me (shhh, lemme have my delusions) the benefits of a truss only come into play over 12" aperture...
You should NOT depend on a truss dob consistently holding collimation, even with the techniques you mention. Even the solid tube dobs like my GSO, which remains close most of the time, still benefit from a tweak now and again, and the f5 means it's not SUPER forgiving of miscollimation. Better than a f4 for sure, but not as loosey-goosey as the 8" f6. The importance of good collimation goes up by the third power of focal ratio.
But, really, I would say do NOT let the tendency to need more or less collimation adjustment be a factor. Ignore that. You can learn collimation easily. With a piece of paper, a sighttube and chesire (or laser), and a glass of beer, one of us could, in 20 minutes or so, leave you totally trained at collimation. Wait....sorry, the glass of beer is part of a different process.....what was I talking about?....
In fact it's better if you do have to make an adjustment regularly, because then you'll stay skilled at it. And any dob may need it, even the solid tube versions, especially if you travel a lot or knock the tube a lot. Even if you don't. Just, buy the scope you can afford and which you can USE (transport, carry, set up, etc) easily and comfortably. (You'll need some EPs, and a few items too, so factor that in. A scope sans EPs isn't much fun...) If a 12" solid tube is going to be a grunting endeavor that exhausts you just thinking about going out some night, then get the truss or a smaller scope.
Cheers
Scott
Quote:
Originally Posted by Jarrod
your right about the size differance of the 8" and 10" lightbridges, they are on almost the same sized mount!
i was actually going to go for the 10" bintel (GSO) dob at first. the 8" sounds like a nice scope, but the portabilty of a truss tube dob means i'll proberly travel with it more. i thought it would be worth paying a bit more for the extra use i'll get out of it.
i was just on the bintel site and the lightbridges have gone on special, the 10" is now $950 . (although the 8" is now only $800).
one concern i have with the lightbridge is collimation: will it be way out of collimation every time i re-assemble it? i read that the lightbridges are pretty good at staying collimated if they are re-assembled with the support poles arranged in the same order every time.
L.
. the 8" is more toward my price range at $900. 
. (although the 8" is now only $800). 
