Thinking out loud - big scopes

[sejanus]

just thought i'd toss this info in here to see what others think

I was planning on getting a 16" LB about 6 months ago but got busy with the building of the business so put it off. I figure I'll get a big scope in dec/jan, or at least order one then.

It doesn't need a computer but I will chuck a navis on later down the track.

The options seem to be - from cheapest to big bucks ;

- GSO 16" , $2400

- Lightbridge 16" , $2700

- Discovery 17.5" :eyepop: I have been emailing them, they seem very professional and have a very good reputation from what I see. The 17.5" f/4.1 is $3999 usd. Shipping/insurance is $525 usd.

I calculate that after customs (biggest ripoff ever :mad2: ) it'll end up costing $5700 AUD to my door.

it is this guy, scroll to the 17.5

http://www.discovery-telescopes.com/discovery/td.html

The 15" version is $1000 usd cheaper, though they reckon the 17.5"
is manageable by one person. I have a nice backyard for this, it'll stay in my garage which is like 3 metres from the observing point. I'll try and put her on wheels if I did it.

Now I reckon that $5700 would be about the limit of my budget and even that is a fair whack. I'd love to support a local aussie, meaning SDM - but he is a fair bit more expensive so I think that rules him out unless someone happens to sell one 2nd hand which i think is fairly unlikely.

So, any thoughts on these choices? I'd really like this scope to last a good few years - any consensus yet on if the lightbridge is built well enough for that, or is it worth the extra dollars for the discovery?

I think the question might also be what is better to use for the buck?

A $2700 16" with a couple of k of nice eyepieces or the discovery 17.5" with my existing televue/hyperion eyepieces.

this is just floating ideas, nothing will be done until late this year but I'm very keen to have a mega scope :thumbsup: I wish I'd pursued that avenue when I first bought all the electronic kit.

[Jarrod]

i personally wouldnt consider buying the 16" GSO dob just yet, id wait 'til they iron out all the bugs.

jarrod

[rmcpb]

If you are really looking at going up have you had tried to source local scope and mirror makers. I saw some really great instruments at the South Pacific Star Party, someone on this forum had a locally made 20" I think and was very happy.

[sejanus]

I suspect the guy you are referring to is Rod, and yes I've no doubt his 20" SDM is a work of art - but they are in a different price bracket to the stuff I am looking at, as much as I'd love one.

[wavelandscott]

I bought a second hand 12.5 inch Discovery Truss Dob reflector and I am pleased with it.

I have heard and read that the quality of the Discovery scopes is generally very good and my experience would support that.

However, I've also read that their delivery times are quite slow in the US...I can only imagine that tacking on a sea voyage after that might make things really really slow.

While I have looked through a 16 inch LB, I have not used it enough to comment on the overall quality and performance...but it does gather a lot of light! By the accounts I've read/heard it is a pretty good value for the money...

I'd wait and see what the GSO 16 inch looked like before "jumping in" and buying one. I have little doubt that eventually it will be a decent scope but I would not be game to be the first kid on the block to own one...

If you are thinking about the long haul, I'd consider the SDM scopes instead of going overseas for a Discovery...the SDM are outstanding quality from what I've seen. Yes, they are really expensive but if it is a once in a life time purchase...

Good Luck!

[sejanus]

thanks for that

the discovery guys said 60-90 days from date of order with 50% deposit, and 7 days once shipped.

I agree about the gso!

[GeoffW1]

Hi,

Do GSO make the 16" Lightbridge mirror anyway? Given GSO's experience, what could go wrong?

Are you thinking that there may be issues with the mount, like stiction in the the usual teflon pads on the alt bearing (az movement is on a roller bearing according to GSO)?

Actually, on a related note, I fancy there is a bit too much flex in the uprights of my Bintel 12" Dob, I think I will brace them a bit. Maybe that is the sort of thing to wait on.

Cheers

[GeoffW1]

Hi,

It would be too much of a financial pole-vault for me, to move that far up in price from a 16" of some sort. You can buy a lot of decent EPs for the difference, and that is half the fun, shopping for EPs.

I can now understand my wife spending the whole day in Myer. Her satellite tracking signal never moves out of ladies' wear.

Cheers

[acropolite]

If it were me, I would buy the 16 inch LB and an Argonavis & encoders, no risk in freight that way and a fair whack to spend on some decent EP's if $5.7K is the limit of your budget.

[norm]

I like the 15" f5 @$3000 US !!! But customs is the killer and a real deterrant.

My only concern would be shipping and any damage in transit, but if insurance covers that it might not be an issue.

Hmmm how can I justify that 15" with the other 1/2:whistle::prey:

Go the 17.5 - you only live once and its only money!!!

[ballaratdragons]

If you only have to move the scope a few metres from the shed, then you don't necessarily need a lightbridge (or any truss tube scope). The solid tube GS 16" would need less collimating. And spend the rest on the Argo Navis, and a couple of top shelf EP's like the Pentax's maybe.

Just my view.

[Jarrod]

id be worried that after a few months of regular use problems may start to arise that the manufacturer didnt anticipate, mainly regarding the mechanics of such a heavy OTA riding on the mount. but you are right, GSO are good at what they do, and the 16" may turn out to be a perfect scope from the very beggining.

jarrod

[astronut]

I agree with Phil, Go with the LB16, it's a good scope at a great price.
Even with the AN you're still under $4K delievered.
The G.S.O. made Lightbridge mirror is of very good quality, with spectacular views.
My 2 cents.:thumbsup:

[sejanus]

If anyone is curious, the shipping cost on a 18" obsession is $1726 USD :eyepop::eyepop::eyepop::eyepop:

[sejanus]

btw guys in regards to the GSO tube - although the scope will primarily be in my backyard I will want to chuck her in the car occasionally, so a truss is definitely the go, whether it be the light bridge or something with more build quality ala obsession styled

[GeoffW1]

Hi,

Yes, agreed, I occasionally put the 300mm Bintel dob in my Camry and go motoring somewhere. It isn't very easy, and once I get the OTA, base, a travel bag, and an esky in, there is no room for anyone else, and the Camry is not a tiny car. I look like a burglar making off with a hot water heater.

Cheers

[ngcles]

Hi Sejanus & All,

I have no direct experience with the GSO but based purely on the 10 and 12" versions I've used, they seem to have good optics, pretty well made and pleasant to use -- particularly considering the very cheap price.

I've had access to two 16" Lightbridges. It is a very good 'scope for the money. Not perfect, but it is serious aperture on a solid functional mount. Of the two I've star and null-ronchi tested, one had okay optics and the other was very good at least -- the seeing wouldn't let me refine it further than that. I don't think GSO makes the optics -- it is another company on the mainland from memory. The focuser is an excellent unit. The mirror cell is not up to the same standard.

I own a Discovery _mirror_ in my 18" Obsession-clone dob which has Argonavis and a servocat. I've had it since 2003. Discovery charged _exactly_ what they quoted up front. Because it had to fit an existing 'scope, I asked them to match the fl (within reason). They matched it to within 5mm -- can hardly ask for more than that. The quality of the mirror is simply superb. They initially promised a 120 day lead time. After a month they emailed me and refined this to 100 days. The mirror was delivered on day 101 from order. Discovery were very easy to deal with. Bill and Terry really do know what they are talking about. All the Discovery optics are made in house I believe.

I've never seen or used a Discovery made 'scope. Based purely on what I hear on other forums they are very good but not in the same league as Obsession, Starmaster etc in terms of build quality (or indeed price!). Most seem to regard them as a good step up from the Meade in build quality and function. They do seem to attract at least some complaints about late delivery on _complete telescopes_.

Yep, the G.S.T when she arrives is the killer and remember you have to calculate it based not only on the value of the 'scope in AUD but also add the shipping in AUD as well. Hope this was of some help. Good luck whichever way you go. There is no substitute for _quality_ raw aperture.
Best,

Les D
Contributing Editor
AS&T

[Rodstar]

....Rod here....One thing you might consider, to keep prices down a bit in going for the upper end of your range, is to get SDM to make you the scope shell (say to accommodate a 15 inches mirror), and then source a mirror second hand, or from GSO. If you check out the SDM website, you will see that approximately half of the SDM scope prices are for the mirror, because brand new premium mirrors are always used, such as from Mark Suchting, Galaxy, or OMI.

So, you could get a 15" scope shell from SDM for something like $3K or $4K, and then put in a seconds mirror for $1.5K or so. That way, you could then upgrade the mirror later on, if you want, to a premium one, but in the meantime have "a work of art" to enjoy! It sure does keep me enthusiastic about going out into the night to take a peek!

GSO do produce reliably good mirrors, and sometimes they turn out to be absolute crackers. You might never need to upgrade the mirror if you get lucky.

Whatever you decide to do, truly, aperture rules! :thumbsup:

[Rodstar]

PS, a 15" scope from SDM, with premium mirror, Feathertouch focuser, and all the bells and whistles, is currently listed on their website as being $7,700. Free delivery!

[sejanus]

Well, I got an offer on a 16" lightbridge at way below retail that i couldn't turn down so thats what I've ended up buying :thumbsup:

[Rodstar]

Gavin, enjoy the POWER that is a large Dobsonian!!!! Yeehaa!

[Starkler]

Thats nice to know :D

[sejanus]

I must have annoyed the cloud gods

scope arrived monday. absolutely crystal clear sky, was a perfect night for viewing. :stargaze:

Unfortunately the scope was missing a couple of screws so had to abandon it.

Last night I had the replacement screws, and assembled the scope fully - and of course it became quite cool & windy, and then clouds began to blow over

:mad2: :doh: :windy: