hotnews - 16 inch GS dob coming soon

[h0ughy]

Just had a very interesting talk with Andrews Communications (Lee) this afternoon:D . It seems as though he will be getting very shortly a new product to sell. A 16" GS F4.8 dobsonian with BK7 glass with Crayford focuser and it will retail between $2000-$2500:cool: .

This should be available inthe next 3 to 6 months. Just in time for christmas for me, santa will have some trouble stuffing that one down the chimney!:eyepop:

But don't ring him now, he is going to china tomorrow for a few weeks on holiday.:abduct:

[ving]

er... like I say to every other thread displaying new wares...

buy me one plz! :D

16 incher hey? well well!

[ausastronomer]

Hi Houghy,

I assume you are talking about the 16" tubed version here ??? I know of someone currently working with Jim Sheng (from GSO) on a 16" truss scope but that is still on the drawing board and very early days.

I would be counting on the 16" scope for Xmas 2006 and not 2005. Experience tells me the likely timeframe will be more like 12 months if the release of the 16" scopes follows a similar path to the release of the 12" scopes. The 12" scopes actually appeared in the marketplace at least 12 mths after the 1st prototypes were run, and 12 mths after Lee's estimated availability schedule, may have even been longer than 12 mths actually. The early prototypes for the 12" scope were for a 2 piece tube and this caused some major design issues with the scope ultimately being released as a single tube design. I can see this again being an issue with the 16" scope and getting the 2 piece design right may take some time, unless GSO are happy to release the 16" scope as a single tube with the non existent portability of the 16" Meade Starfinder, which I doubt. The other issue that delayed the availability of the 12" scopes was sourcing the blanks for the primary mirrors. GSO had a lot of difficulty sourcing 12" mirror blanks at the time the 12" scopes were due to be released and could not source Asian made 12" blanks. I believe all of the early production scopes used American sourced Pyrex blanks as opposed to Asian sourced BK7 blanks. I am not sure what the sourcing of the 16" blanks will be and whether any issues will present.

Not trying to put a dampener on things but merely to give people some thoughts as to what may be a realistic timeframe for the release of these scopes.

CS-John Bambury

[slice of heaven]

Lee mentioned the 16" to me in early March. At the time he gave me the impression the release date was more along the lines of
Aus' post.
The 4" jump doesnt get me excited though. A 20" would be better.

Slice

[Starkler]

For me a 16 inch truss dob would be ideal and about as big as I would want to set up and use single handedly. F4.8 is going to require a step for viewing at zenith methinks.

[ausastronomer]

Geoff,

Yup, eyepiece height at the zenith of about 6' 4" without an equ table.

CS-John B

[slice of heaven]

Starkler
The jump from a 10" to a 16" would be great.
I've had my eye stuck in a 12" for so long I need a bigger than 16" ap to get that WOW factor to justify the step up.
I was being conservative in stating a 20" by the way. That still falls way short of what I really desire.

Slice

[h0ughy]

John,

I was just reiterating what discussion took place. Ultimately it is the manufacturer that controls everything. But it is great to dream that you can get a scope that size for around that price. Whether is comes this year or early next year doesn't matter. What does matter is that it is going to happen (sooner would be great, later is ok)! But i don't think that Lee andrews would drop such a big news item like this for nothing. there must be some substance in it, after all it will mean more orders for him and more $$$. Given Celestrons "demise" and meade's market share i would say the "new kid on the block " is looking to get more of the current market. What better way than a cheap quality light bucket. Just add an argo narvis and everything is sweet! its a pushto!:clap:

[MiG]

Is there any point using BK7 over plate glass (thermal characteristics are very similar)? At that size Pyrex would be getting pretty useful wouldn't it?

BTW, don't forget that the 4" increase results in 1.78x more light gathering area, though I suppose that isn't that much of a jump either. Still, it's more responsible to build up the product line rather than making an enormous leap in size.

[h0ughy]

MiG

if you can get to sydney in a 1972 datsun (plate glass), or you can get there in a well for arguement sake lets say a GMH 2005 monaro(BK7), what woud you take. ( no sentimental the datsun would be an experience answers accepted!)

[slice of heaven]

Cheap 'quality' light bucket , Houghy.
'Cheaper'..maybe...quality..I doubt it.
Quality means; straight out of the box ,no major improvements necessary.
gs have yet to bring out a scope like that.

Slice

[h0ughy]

Slice

GS or synta? if you only had a few dollars which would you choose?

[slice of heaven]

If I only had a few dollars (and sometimes that's the case) I'd hire a good DVD and watch it with the Kids.
If your talking TWO AND A HALF THOUSAND dollars I'd be looking around the buy and sell marts and see what comes up.
There are absolute bargains to be found for those who have patience and search.
I've done it twice. One of my scopes I purchased for less than a cheap ep. The other I purchased for less than a 2x Powermate.
Both TOP quality OT's.
IF gs and Synta were the "only" lens/mirror manufacturers available I would choose Synta for the lenses and gs for the mirrors. IF that was the case I'd surely hope they'd both improve on their standards for their 'completed' products.
But seeing as other brands of optics ARE still available, a larger mirrored scope of mine would have optics sourced from a better
company.
But that's the same difference as you stated before
A $50 72 datto or a $50,000 s/hand Monaro.
You (hopefully) get what you pay for.

Slice

[h0ughy]

Very true. But for those who seek bang for bucks, it seems like good value for me. I'm nowhere near the handyman type so for me my choice was easy, a meade 12" LX200. But once i finally get it set up in that imaginary observatory I keep telling myself about, I will need a scope to attend star parties and school visits. To get something like this would be a bonus. I do agree you get exactly what you pay for, but occasionaly you can get a rose amoungst the thorns! :)

[slice of heaven]

Your observatory is in the research stage Houghy, its not imaginary. As is my larger scope. We're not dead yet so we can still say "One day".

Slice

[RAJAH235]

I wish you guys would take it easy on US, that's us, Datsun owners. I have a '78 200B wagon.(cost me $270 back in '93). Does me O.K. I can fix almost everything on it. But it never breaks down. Just gotta keep chasing the %#%^&&*$# RUST!
As for the larger DOBs, one member had a Meade 16", but he had a 1 ton table-top at the time, so he didn't have any transport probs.(Company stuffed him tho., they gave him a car. Had to sell the 1 ton & the 16").
Ended up with an 8" Celestron.
Will be interesting to see the 'new' DOB when it is released, & the actual optics they pick. Surely they would have to use 'PYREX' for that size! :D :P L.

[iceman]

Interesting! 16" sure is some light gathering power.. in my opinion it would make a significant difference when viewing faint fuzzies..

A tube for a 16" dob is going to be hell to transport though.. they'd surely need to make it in 2 pieces like the Meade 16"ers.

I can't see it being released soon but it's an interesting prospect for those with aperture fever.

[h0ughy]

maybe it could be a truss design as John said. It would make it more portable.

[ballaratdragons]

At $2500 I would rather get Goto on an EQ for my 12".

[Starkler]

What does $2500 normally buy you ?

Half of an LX200 10 incher?
Two thirds of a C8 ?

If you can get 16 inches of good quality aperture for $2500 its a damn good buy. If the mechanicals are otherwise ok it could even be worth getting Mr Suchting to resurface the mirror to make it a premium job.
If you import an obsession dob of this size I think they run about $7000AU

[ausastronomer]

Thats exactly what I would have thought.

BK7 (Borosilicate Crown) is an optical glass that was originally designed for making refractive light transmitting elements, not front surface reflective optics. In terms of Newtonian mirrors it is way better than plate glass but certainly not quite as good as pyrex or the more exotic materials in terms of its thermal expansion co-efficient. In smaller mirrors up to 12" it does a very good job and GSO have produced some outstanding BK7 mirrors considering they are mass produced. When you get to a 16" mirror the thermal properties of the glass become a lot more critical than they do in smaller mirrors, this also applies to grinding the mirror as well as observing with it. On the basis that GSO would be ordering a large number of these 16" mirror blanks I would have thought the minimal additional cost of going to pyrex instead of BK7 with mirrors of this size would be well worth it.

I am not sure whether or not the 16" truss scope will ever happen, truss scopes is an area GSO have never gone before, but I would like to think that it can happen. I do know that an Aussie, very experienced in designing and building truss scopes is currently providing them with a lot of design input for such a scope.

CS-John B

[Rodstar]

16 inches......sounds good to me, HOughy!

I'm just trying to think of what explanation I can give to The Other Half about why I need to buy ANOTHER scope.

Wouldn't it be nice to have the option of a stand-by 16" light bucket, just in case you have trouble seeing something at the limits of your ordinary scope??!! Would my dear wife swallow that line? (Methinks NOT).

GS have produced some pleasant surprises with some of their other products (especially EPs). Maybe this scope will carry on that fine tradition. I for one am very interested to learn more.

[MiG]

Since what matters is coefficient of thermal expansion and heat diffusivity, it's more like a comparison between a 1972 Datsun and a 1978 Datsun with a flashy paintjob. BK7 isn't much better for mirrors than plate glass.
So it comes down to the price difference. If they're roughly the same price you take the slightly newer Datsun that looks nice. Otherwise you don't bother.

[gaa_ian]

Good call starkler ...
I will be watching this one with interest too ..
The upgrade from a 10 to a 12" is not inviting enough for me ... 16" of aperture though !
I can think of 100's of DSO's I would love to see through that size scope.
Beam me up scotty ... the universe awaits :abduct:

[h0ughy]

nice to see a bit of passion from the dato' owners out there. Personally the 1600 with all the trimmings was a goal of mine when I was way younger.

Personally I started with a 80mm tacso refractor when I was 18, then went to a 8" celestron (no dec motor) when our first child came on board, went to a 10" meade (no dec motor), then bought a meade etx 90RA from a NZder, then won a meade 12" lx200 buzz click whirrr, then a celestron 4gt (i sold the etx), then for solar a PST ( really wanted to 90mm Coranado), now who says I suffer from aperture fever!!!!

But to get something reasonable like 16" for the price has got me hooked.

[dhumpie]

A cheap 16" fast newt. Oh that's going to be very tricky to pull off. At those fast focal lengths, you probably need hand figuring in addition to the general figuring they do with machines. I wonder how GS is going to pull that one off for a low price. And if they are going the way of the truss, I would think the price to be more along the lines of Discovery (maybe a little bit cheaper). Just my 2 cents.

Darren

[slice of heaven]

Yes Darren
I hope they've got something up their sleeve to pull off that trick.
I finally had the chance/time/energy to directly compare the gs12" to the Parks 12".
The Parks definately has the edge over the gs in contrast and sharpness but I have to admit the gs still gives a fantastic view. There is definitely nothing nasty about the gs optical performance.
The optics are the heart and soul of any scope. It's the one place you cant take shortcuts.

Slice

[ausastronomer]

Geoff,

20 years ago Parks and Cave scopes were at the top of the tree. For the mass produced 12" GS scope to even get close to a high grade scope like the Parks is praise in itself.

CS-John B

[slice of heaven]

Yes Aus I was surprised myself.
One thing I didn't mention was the Parks probably does need its mirrors recoated. But I cant tell how much this difference this would make until I actually have it done. The surfaces dont show any obvious major marks or blemishes but time has to take its toll on coatings. It maybe 20yrs old.
Regardless of that, the absence of anything 'nasty' that I could see has to give the gs scope it's strongpoint.

Slice

[bytor666]

Plate glass? pyrex? Bk7? I think for a nice cheap 16" light bucket the figure of the mirror itself matters much MORE than the substrate used .
If it is cheap, I'd lay down my money for a nice size scope like this because it would mainly be used for "deep sky" work anyways.

People need to not be so fussy about what the mirrors are made out of, heck even the older 100 inch mirrors were made out of PLATE GLASS with bubbles all inside of it and those were amazing telescopes.
------------------------------
Mark
12" gso scope

[Orion]

I agree. We spent some considerable time figuring my mirror and it is an 18" f4.5 (30mm plate glass) If I would have brought a Pyrex blank I wouldn't have had the money to build the telescope.

[MiG]

But the Hooker telescope is kept in an insulated dome so that there is little temperature variation. This is slightly impractical for us. Stargazers don't want to have a two hour cooldown time after bringing the scope from indoors. Pyrex will still have a long cooldown time, but the strains during that time are less than half of plate glass so the distortion won't be as bad.
Of course, once equilibrium is achieved the figure is what matters.

[slice of heaven]

Spot on MiG
The figuring of the mirror is the greatest concern.
At the moment the current sized gs mirrors are well made and affordable and that's their strongpoint on these scopes.
Up the price and reduce the quality of the optics and that would be the downfall of a larger mirrored gs scope. Regardless of how bad/good their ot and base design is, if the optics dont cut it, they'll only be bought by the desperates or unwary.

slice

[h0ughy]

Slice

are you call'n me desperate or unwary????

Damn, I hate when the truth comes out.

[Starkler]

Too right, and if cool down is an issue, add some fans to scrub the thermal boundary layer.

[slice of heaven]

Sorry to let the cat out of the bag Houghy. lol

That was 'if' the optics dont cut it. Hopefully they wont take a shortcut in that area.

The substrate stated originally in the first post was bk7.

Then you still have to worry about the ot assembly and base.
They dont have a good track record in those areas.
By the way. I've noticed a few upgrade packages available in the states for their bases. Side braces...cross supports....thicker base plates...to remove the shakes and wobbles.

Slice

[h0ughy]

will have to just wait and see

[h0ughy]

I have just had another discussion with Andrew's, the 16's were due for delivery in September of this year, but he doesn't expect them until christmas of this year.

Now I am busily collecting aluminium cans for $crap, robbing pensioners:P, slealing the tuck shop money from the kids and saving for this expected delivery date!:cool:

[MiG]

People might also need to save up for the station wagon or ute to carry the scope :)

[h0ughy]

But it would be worth it. I think it would fit in the subaru with the seat laid down. The car is pretty full with the LX200 stuff, so the 16 inch will be ok

[Starkler]

I wanna know more about this !

Any updates ? Google hasnt helped

[asimov]

I can see exactly what would happen to a newbie soon. The 8" dob 'starter-kit' as a recommendation will be obselete. Why bother with an 8" when there's a 90% chance of getting the 'fever'? Just go straight for the 16"! At that price, I'll get TWO! :evil:

[ballaratdragons]

Anyone heard any more about the 16" yet?

[davidpretorius]

more important, will it fit mike's eq6 or will three chops sticks and a rubber band do the job?

how long will this sucker be?

[gaa_ian]

I was wondering too Ken ... I'm ready to trade up & want to go bigger than a 12" ...more, more, gimme more :einstein: :stargaze:

[asimov]

Still small enough to fit in a station wagon lol.

[asimov]

for sale....12.5" newt! NO MOUNT!! A 16" is going on that baby!!:thumbsup:

[ballaratdragons]

Need an old Hearse to carry it. The Carpetlayer here in Snake Valley uses one (Hearse that is).

[asimov]

I would imagine it would be F/5....or possibly shorter? I'll have to do the sums on that to get the length...:confuse3:

[ballaratdragons]

Can't remember exactly but I think Geoff? (Starkler) said it was f4.5 :confused:

[RAJAH235]

It's prob. around 6'6" to 7' high. Sounds similar to the Meade 16" f4.5 (Sonotube).You'll definitely need a set of kitchen steps/ladder to view anywhere above 60 degs. (depending on your height, of course)! :D L.

[Starkler]

Wasnt me Ken , But i recall f4.7 or 4.8 being mentioned

[ving]

ok guys, one of the people in my astro group has been talking to lee...
16" f4.6 truss
being trus i guess you can take it apart?
available early next year (for my birthday)
@ a bit over $2k.

as much as i know...
but its a definite.

[Starkler]

I want photos ! specifications !
I want.... i want ..... :D

[iceman]

16" for $2k! Bargain!

[ving]

I have just gotta save my money!:prey:

[h0ughy]

Don't hold him to that, I spoke to him as well about two weeks ago. Price and availability are not known, although an expected delivery target date of around May was suggested. :D

[ballaratdragons]

That's roughly $125 per inch. That makes it a lot dearer than other GS sizes per inch but it's still very cheap!

[h0ughy]

ahh yes but the gain in magnitudes is logarithmic ken.....................

[ballaratdragons]

Is that all you could come up with Houghy?

I was waiting for all the mathemetician type members to jump in and say "but consider the area per dollar as the increase cannot be measured by inches of diameter. Dollar-wise we must consider the size of area of a 16" over the 12", 10", 8" and 6"." :D

[ballaratdragons]

I'll play the mathematician!

This is the Area of each size:

6" - 28.274"
8" - 50.265"
10' - 78.54"
12" - 113.1"


But the 16" area is - 201.06" :scared2:

Pretty cool huh! Almost twice that of a 12" Dobbie!!!!!!!!!!!!!!!

Which equates down to $9.95 per square inch for the 16" compared to $10.60 per Sq inch for a 12" etc.

[xstream]

I want........Pity it wont be here before SPSP 2006
I wonder if we can hurry them up?

[ballaratdragons]

John, a quick trip to Taiwan and pick one up at the factory? Maybe one of the demo models. Offer them $500 cash.

[cometcatcher]

I made a 16" f5.4 dob for $1200. Took a few short cuts though like using PVC pipe for a focuser.

[ballaratdragons]

Excellent Kevin.

Peter Read has booked into the Snake Valley Star Camp and will be doing a presentation on building an obsession truss-dob! Sounds good!!

[xstream]

$500 you reckon Ken! :confuse3:

"Trip to Taiwan", now you've got me thinking. :rofl:

[ballaratdragons]

Quick John, only 36 sleeps till the Camp. You will need it for that!

[xstream]

Just a minute........Hey Anna, do you think it will be okay for me to go to............. :scared3:

[anna]

Off you go. But there's just a small problem.
What about that camera you said you had to have that's
still on layby.

[ballaratdragons]

Family tiffs. Oh dear! Hi Anna, he won't be gone for more than 24 hours! It's only a 16" scope, real cheap!! LOL!

[ballaratdragons]

You can look through it too at the Camp. John will let you, won't you John, . . John . . .

He's already on the plane to Taiwan, WOW!

[ving]

lol!

[anna]

Sorry Ken, he can't hear you. I've locked him up in the grandkids bedroom.

[ballaratdragons]

Ah hah! He is sneaking out the window Anna! Looks like he won't get to work on time tonight! Not unless there is a plane arriving back from Taiwan before 2 am. LOL!!

[h0ughy]

That's why you are here Ken, your the sharpest one here mate :poke: :poke: :scared2:

[TidaLpHasE]

:confuse3:I wonder if they will check the mirrors before delivery:poke:

[ballaratdragons]

LOL!!!!! hey Trevor, there will be no excuses. They are truss-dobs. Just open the lid of the box and look in. The mirror will be there to see. (that's if he opens the lid! :confused: )

[ballaratdragons]

Hehehe! as a bowling ball. :doh:

[slice of heaven]

So by upgrading from a 12" to the 16" you'll gain roughly 1 mag, and whatever in resolution (I'm too googled out from the quiz to look) for those $$$$.
Are they going to bring out a larger size in the future to make it worthwhile for the 12" brigade to upgrade ?
A 20" or 24" would be nice :)

[ballaratdragons]

I can't justify the upgrade either Slick. If I was an 8"er or even a 10"er it would be worth it. But I don't think it will draw in many 12"ers. They do sound cheap though.

A good cheap bargain for newbies :rofl:

[janoskiss]

One mag gain is a lot! Consider mag 4.5 vs mag 5.5 skies. Check out the attached xephem simulated images of M11. The first one is with a visibility limit of mag 13, the second one with mag 14.

[gaa_ian]

Yep ... I still want one !
I believe Bintel will be getting them too, but May 2006 delivery, sooner i hope :rolleyes:
I want one for Xmas :xmas: :tasdevil:

[ballaratdragons]

It would be a great step-up for you Ian and Steve. OK, you can have one each! But only if you behave yourselves!! If not, you will have to give them to Ving.

[Starkler]

The other factor obviously is that a truss dob breaks down into smaller pieces.
A 12 inch tube dob isnt transportable in the average family sedan. :whistle:

[ballaratdragons]

I do hope the instructions for it are written clearly.

Think you for purchasing your 16" russ Dobsonian Telescope
AssembleInstructions:
Please place the truss the number 1 into sacket 'A'. Proceed to turn the frame around to other side and followed the step 1.
Once the installed part comply it, placing the next truss number 2 into the sock 'B'.
The truss frame must reproduce around all sides. On complete of this part, putting all truss into the basis and lock click onto place using the clocks supplied.
Attach all truss and base onto main base stand and to looking angle is good and align using the aligner screws.
Please to turn the focuser housing unit device section to suitable be placed for your comfort viewing and lock unto place.
We hope you enjoy your the telescoper.

[slice of heaven]

Nice comparison Steve, can you post a comparison of mag15 and mag16 skies?

[janoskiss]

Xephem downloads the faint stars on the fly, so I only have up to mag 6 actually stored on the computer.

Slice, Do you realise how many mag 16 stars there are up there? :P The database must be around 100GB or maybe bigger. The one I normally use goes to mag 14. I'll see if I can find one that goes deeper. :D

[slice of heaven]

:lol: Thanks Steve
I didnt realize that, sorry

[janoskiss]

Never mind Slice, I got them! M11 at mag 15 & 16 attached. Narrower field of view to keep the downloads manageable (around 1/4 degree here vs around 1.3 in the earlier pics). It tells a similar story though as the mag 13-14 comparison.

[slice of heaven]

Thats pretty snazzy seeing them like that, Thanks Steve.
There's a definite difference for sure, but maybe not enough for me to have a 'eyegasm' and warrant that jump. Still I could imagine the feeling jumping from an 8 to a 16.

[gaa_ian]

Ken ... so you have a new job !
Writing manuals for GS & Synta, well done :thumbsup:
Your much happines felling be certan :D

[ballaratdragons]

LOL! I am not racist one bit, but be honest, how many instructions manuals read like that! A lot!

I even seen written on a very expensive Video game machine in a Games Arcade "Place coin slot into opening to the play the game" and it wasn't written by the proprietor. It was Etch printed on the factory's steel plate on the coin entry slot!
:shrug: Don't they have anyone to proof read?

[janoskiss]

They don't NEED anyone to proofread! We all buy the products anyway.

But it is getting better as China is putting its foot down on the globe. Soon enough, there will be Aussie engineers eager to go work for Chinese companies, and basic spoken and written Chinese will be taught as part of their engineering degrees. Just try to keep up! :thumbsup:

[Astroman]

I am sort of leaning towards it now, I considered jumping to a 16" because I already have the 8" and started off with a 4" so I have to keep doubling my viewing pleasure. BUT! I also wanted tracking for photography. I think I will wait until the bugs are sorted out first

[iceman]

hmm it would be very tempting as a next scope to satisfy some aperture fever.. the fact that it's truss and would be easier to transport, as Geoff says.

But at > $2k it would mean the DSLR would have to wait :)

Oh and also this is all before telling the wife, "honey, I need a bigger telescope".

[xstream]

Yeah look at me. Locked in the grandkids bedroom. :rofl: :rofl:

[ving]

really?
sir you are blind. theres a huge difference to me there :)
how bout this... you buy the 16" and give me your 12" ;) :poke:

[janoskiss]

I wonder if you'll be able to buy just the mirror and for how much... The 12" mirrors are just $399 ea. I'm seriously considering getting one, but 16" would be an even better excuse to start an ATM project. :D
I'm eager to see the difference between 8" & 12" with my eyes at Star Camp. :jump2:

[slice of heaven]

Your probably right Ving, the old eyes aren't what they used to be.
But I was also taking into account I can go deeper with the 12.5" Parks than the gs 12" and the pics are only a simulation.

How about you buying the 16", send it to me and I'll compare it to the 12", if it's worthwhile keeping I'll buy it off you for half price cause it'll be second hand then :)

[ving]

lol, its a deal
/me runs away :scared3:

[miketheobscure]

Who's selling the GS mirrors for ATMers?

I'm too Googled out by the quiz too, my search skills are Schott (boom boom).

Regards, Mike

[janoskiss]

Andrews has been advertising them in AS&T.

[miketheobscure]

Ah, got it ta.

Stuck in under the Dob pic, I'd seen that add several times without noticing it.:ashamed: Well spotted.

Regards, Mike

[Starkler]

Thats a bargain considering they are normally $699 !

[h0ughy]

well to add to this endearing post - the meade 16" wont be available until around march if we are lucky, and the gso version wont be available until may/june. butthey are real and they are not vapourware. nearly two years will have passed where everyone got their hopes up...............and still waiting

[acropolite]

Bintel are offering 16 inch mirrors (https://www.bintelshop.com.au/Product.aspx?ID=7446) soon at $1699...

[h0ughy]

Umm just opened the link, the saw us coming and upped the price to $1799:whistle:

[acropolite]

OOPs better make that $1799. :lol2: