Biggest amature scope?

Hemiduty · #1 17-01-2007, 08:01 PM

So who here has the biggest scope?

Any wild custom built monsters out there?

Striker (Tony) · #2 17-01-2007, 08:05 PM

at the moment my biggest scope is a wopping 50mm finder scope....does that count......lol

leon · #3 17-01-2007, 08:09 PM

Ah Big isnt everything, it's how you use it that counts, but i'm sure there are some monsters out there.
Cheers leon

[1ponders] (Paul) · #4 17-01-2007, 08:25 PM

http://www.sdmtelescopes.com.au/

Now these are telescopes to drool over.

Gama · #5 17-01-2007, 08:39 PM

No reason to drool, in fact there is no gain except for imaging where a large aperature scope is going to benifit you in a suburben sky.
I had a 20" Obssession and a 10" LX200 and for visual, really didnt do anything much. I now have a 22" and still, only benefit is imaging, unless you can go to a dark site.
Plus you also have the problems of coma which will waste most light as it spreads its focus over a large area. You then need to spend money on coma correctors on top of this.
A 16" is about the limit for a good scope for suburben skies, anything else is really benefiting imaging.
I once also wished for a large scope, now that i have it, i use my 14" 10 to 1 more times over the 22".
Leon got it right, "Its how you use it that counts", and thats spot on.

Starkler (Geoff) · #6 17-01-2007, 09:22 PM

42" truss dob

Rodstar (Rod) · #7 17-01-2007, 09:29 PM

Hemiduty,

Welcome to IIS!

The biggest amateur scopes that I know about are at the 30" mark. As Paul has indicated, two of these were manufactured by SDM telescopes, with the owners of both SDM #1 and SDM #2 members of the forum.

OMI Torus, a US mirror making company, has just installed a 30" mirror grinding set-up because this size is beginning to grow in popularity. There is probably less than half a dozen scopes of this size in Australia. There is probably another 30 or so amateur-owned scopes in the 20"-25" size in Australia, mostly made by Obsession Telescopes of Winsconsin USA.

The various scope sizes have their ups and downs. Some 6" refractors give the most beautifully pin-point star images you could hope for, which would be great for imaging, but could cost 15x as much as a 10" reflector which gathers more light is therefore better for tracking down faint fuzzies.

I have studiously avoided catching the imaging bug to date. I am particularly interested in visual observation of faint galaxies. In my experience you really need 18 plus inches to see any major detail in most of the well-known galaxies. I have enjoyed the best views of my observing life in a 20 inch Obsession style dobsonian reflector. It totally blows the views of a 10" scope out of the water. Whilst I have avoided catching the imaging bug, I have caught a fatal case of aperture fever, and am awaiting delivery of a 20" SDM scope.

There can be a great deal of variation in the quality of mirrors, and collimation can make a big difference. One 18" scope that I know of has a very poor mirror, and for that reason I would compare the views from it to a good quality 10 - 12" mirror.

grl570810 (Graham) · #8 18-01-2007, 10:34 AM

Someone turned up at the ASNSW SPSP two or three years back with a (from memory) 36" Nasmyth design.

He had hired a furniture removal truck to get it there! That's the biggest thing I've heard about / seen in Australia - I got to look through it for about 30 seconds 'cos the queue was so big, then spent the rest of the night having much more fun comparing views through an 18" Obsession (that had fortuitously set up next to me) with those through my 4" Synta. The 4" wasn't so badly done by as you might expect - you'd be suprised what you can see through one of those with a bit of experience and some serious dark adaptation.....

Others may recall the monster scope and be able to supply more details.

sejanus (Gavin) · #9 18-01-2007, 10:38 AM

HOLY ****E!

Quote:

Originally Posted by Starkler

42" truss dob

Argonavis (William) · #10 22-01-2007, 01:26 PM

A rumour is told about a 36 inch located near Alice Springs which is kept mothballed, except for a few weeks a year when the owner travels from the UK to use it.

g__day (Matthew) · #11 23-01-2007, 02:15 AM

I just came back from 2 days spent at Darby Falls (home to a 40cm and 50 cm dob) and then Magellan Observatory (60 cm dob F3.7 using Argo Navis in a 4 metre fibreglass observatory amongst 6 other great scopes and a few high end GE mounts and S-BIG ccd's).

It's not just raw size, its clearly focus, tracking, collimination, f-ratio and a few other very important things that matter; I've sent a detailed review of these two observatories and their respective hosts to Mike in case he wishes to display my views on each.

Bottom line - Magellan wins by a clear country mile on multiple fronts, performance, visuals, focusing, tracking and go to, facilities, hospitality, range of high end scopes / mounts / ccds, value for money - its a walkover!

Orion · #12 23-01-2007, 04:35 AM

A bloke I know is building a 48" he is working on the mirror at the moment but the telescope is finished.
You walk into his back yard and you see that it is enormous.

NewToStars (Jase) · #13 23-01-2007, 10:59 AM

orion - the people demand pictures

Hemiduty · #14 25-01-2007, 01:28 AM

Wow some serious scopes amongst that lot!

Sure does look like a lot of work though, once you go over 12"-18". Still the views would be great.

Thanks for the replies.