Telescope question

[BC]

Hi I'm new here,

I’m trying to figure out the best telescope for my requirements which will be suitable for a long time and I would value any advice you might be able to give. The moon and planets are certainly of some interest but I’m very interested in the deep sky as we live with dark skies on 40 acres at 900m altitude with a 360 degree view. I’ve been reading excessively about various characteristics of aperture, f ratios etc and have come to the conclusion that a good all-round size is the 200 x 1200mm reflector, as is often used in Dobsonian arrangements. The f 6 ratio sounds more forgiving in the optics and a good light gathering scope. Unfortunately, I’m not all that keen on the Dob mount as I can see the situation where I get it all set up for the kids to see and then the object has either moved out of view or they bump it slightly and we’re off a few million kms.

It seems that an excellent package would be a 200 x 1200mm reflector (with 2” Crayford focuser) on an EQ5 mount. No one seems to sell such specs. The longest seems to be 200 x 1000. Is the 1200mm too ungainly to work, or is it the strength of the mount that is the issue? Further to that, if the mount is the issue, is it the head or the legs? I’m more than happy to set a pier into the ground. Would the EQ5 head be adequate and can it be readily attached to a pier?

So many questions…

BC

[mch62 (Mark)]

Ok if your after a tracking mount for the long term and an 200x1200 Newtonian you would be better of with an HEQ5 or better still an EQ6 to this add the OTA that you want.
The EQ6 will handle up to 18-25kgs with OTA's to about 1500mm long and aperature to 254mm or 1200 x300mm.
Any longer than this and the torque becomes to much for the gear train.
With a 200x1200 OTa it will be just cruising and provide a very stable platform .
As far as the OTA the GSO's appears to be the pick over the Chinese conterparts.
Andrews inSydney have a GS680 Dobsonian (200x1200) that you could use the OTA from and mount on the EQ6 and yes the f6 will be more forgiving for a newbie as far as collimation and eyepieces go.
He also has the EQ6 at a good price as well.

This rig will allow for added accesories as well as the future OTA upgrade if required.
Also the EQ6 can be upgraded to Go-To as well.
The EQ6 is a popular mount with many after market add ons available.
The EQ5 would be pushing the limits for that size OTA.

Andrews has another brand of mount (SV2) for sale but have not been able to track down a lot of info on the them , no info on specs or reviews ect on the web.
He states there better the the Eq's but i don't like the uncertanty.
i have an Eq6 and for the mony there very good and with a little work are an excellent mount.

Mark

[atalas]

BC I hope you enjoy It here !

Mark has said what needs to be said about your choice of scope and mounting. Theres not much ells to ad to It.

Louie

[ving (David)]

Nothing to add to what mark has said really. the eq5 would be a little flimsy. go a 6

and most of all, welcome to the forum

[BC]

Thanks very much for such prompt replies. Whew.. EQ6 eh, I guess I'll have to look at things again. $400 for the 8" Dob, ~$2,000 for the same thing on a good mount. I was hoping to get set up for ~$1,000. The wheels of my brain keep turning.

BC

[ving (David)]

you could still go the dob but purchase some wide FOV EPs to go with it...

just a thought

[rmcpb (Rob)]

How about the dob with either a bought equatorial platform or, if you are a bit handy, make one yourself all for less than $1000.

If you buy the platform, just look at the savings on wide angle eyepieces

[slice of heaven]

Mick Pinner has an eq6 up for sale.$1000. Check the buy and sell forum.
Andrews had an 8" ota in their returns section on their website for $229.
http://www.andrewscom.com.au/site-co...10-surplus.htm
Thats pretty close to your price range and would make a good setup.

[ving (David)]

good find slice!

there you go matey! done for ya!

[stringscope (Ian)]

Hi BC.

I understand you might live near Canberra. Just in case you are not already a member of the Canberra Astronomical Society, we will be holding a deep sky night this Saturday. We usually get quite a number of different scopes to these events and it is a really good opportunity to look at and try out different scopes and "stuff". I would expect several GSO Dobs plus others right through to 1 or 2 Meade 14"LX200's and several large Dob's. Non members are welcome. if you are interested send me a PM and I can give you some contact details.

Cheers,

[Starkler (Geoff)]

As it appears that you are a newcommer to the scene I would suggest you dont dismiss the dobsonian mount without a good look.

Simplicity, stability, price and intuitive aiming are the strong points of the dobsonian mount. The eq mount is the opposite meaning you have to spend a lot of money to get a stable mount for a scope of decent size, and then its a heavy pig of a thing to move and more often than not , the eyepiece is at some awkward viewing angle necessitating rotating the tube.

After owning and using a dob , i bought myself a short tube refractor on an eq mount. I found it awkward and annoying to use. That eq is now an alt-az

[Starkler (Geoff)]

Slice I used to own one the saxon/skywatcher 200mm f5 dobs.
Whilst not a bad scope, its primary suffered from spherical abberations and the GS mirrors are definately a notch above.

Having said that, I have contemplated buying that OTA, making a base for it and using it as a portable travel dob

[acropolite (Phil)]

BC Said

we live with dark skies on 40 acres at 900m altitude with a 360 degree view.

Given that you have such a good site I would choose the largest aperture that you can afford even if at the expense of tracking.

[ausastronomer (John Bambury)]

Hi BC and Welcome to the Group,

I tend to agree with Geoff and Phil. I have owned both dobsonians and equatorially mounted scopes over many years and for visual observing much prefer a dob. If you want to take "top class" astrophotos then you need a tracking mount.

Given that your skies are good you are better off going for as much aperture as you can afford and given your budget, decent aperture will only come on a dobsonian mount. However just because dob mounts are cheap they aren't crappy, they are in fact more solid and vibration free than "most" equatorial mounts (some exceptions), as you correctly point out what they lack is the ability to track motorised in there simple format.

Don't be put off by faster F-Ratio scopes, anything slower than F5 is manageable for a beginner in terms of collimation and eyepieces, however there will be compromises. eg. $80 widefield eyepieces won't work well at F5 but they dont work well at F6 either so this shouldn't be a consideration. There are any number of top quality medium cost eyepieces that perform exceptionally well at F5 eg Uo orthos, Celestron Ultimas and televue Plossls all cost under $150 and provide superb image quality in an F5 scope. The downside of these eyepieces is a narrower FOV and short eye relief.

You are placing a major emphasis on difficulty tracking with a dob. You shouldn't its not hard, I can track with my 10" dob at over 500X on planets and my 8 yr old can track at 300X with it. What it takes is a little bit of practice and I mean a little bit, not a lot. Given lots of experience you can almost track with a dob like its a driven mount. I can have Jupiter in the FOV at 250X, leave the scope stationary for several minutes, come back to the scope and pull it straight back into the FOV without the finder 9/10 times (because I know where its moving) this comes with experience but there is nothing difficult with using a dob from day one. A dob can also be fitted easily with DSC's which are computerised aid in finding objects very easily.

I think you would be well served with a 10"/f5 GSO dob and you would have money left for some necessary accessories, like star charts a couple of good books, a planisphere and a red torch.

I suggest you take Strings advice and attend some star parties and spend some time using different types and sizes of scopes to see what you like to look through. Then I think you should attend the next star party and take careful note of all the guys "frigging around wasting precious time and experiencing all sorts of hassles" setting up their equatorially mounted scopes compared to how long it takes the guys to set up there 10" dobs. You will find the guys with 10" dobs start observing 20 minutes before the guys with eq mounts and when it comes time to pack up you will find the guys with 10" dobs home in bed asleep while the eq mount guys are still frigging around folding up their tripod legs.

I think eq mounts are great but they are definately more suited to a permanent observatory situation IMO. A medium sized dob in the 8" to 12" class is certainly a LOT more portable and convenient than an 8" eq mounted newt IMO.

BTW my advice is free and worth every penny

CS-John B

[Starkler (Geoff)]

Oh yes, a small extension to what John said about mounts....

A scope thats easy to use will get used more

[RAJAH235]

I'll say one thing, Rule #1 'APERTURE WINS'. Good luck with your choice. L.
ps. God, all that dark sky!!!!!
pps. Oh, & Welcome to the nuthouse, BC .

[slice of heaven]

BC, You mentioned you were willing to set up a pier. I presume you are looking for more of a permanent setup. If thats the case I'd go with the EQ6 mount. Stable with dual drives and easily upgradeable to goto as mhodson stated.
If you've truly dark skies thats worth a couple of inches or more of aperture in itself.

[iceman (Mike)]

Hi BC, to the forum! How did you hear about us?

I won't rehash the good advice everyone else has already said. But it really depends on a couple of things:

a) Your budget
b) Do you want to do astrophotography?

If you want to do astrophotography, then definitely a pier mounted EQ6 head, or an EQ6 tripod mounted is the way to go. But of course it costs more. If you live in dark skies with good views alround, it may be worth the extra expense to get a pier setup. However that can also be an option down the track, as you'll need to think about housing it (observatory?).

The quick and easy option is the dob mounted newt - just put it on a trolley and wheel it out to your location and you're ready to go in no time. Tracking is an issue, but not a major one. When i'm showing my kids, I set up the object in one edge of the FOV and let it drift through, so by the time the kids get their eye to the EP it should be in the center. But it also depends on the magnification you're using and what object you're looking at. At lower mags you have plenty of time to get the kids to the eyepiece.

An EQ platform is definitely an option, for less money than a tracking EQ mount - i've bought one that hopefully will arrive in the next 7 days. For around AU$650 it gives me tracking while still maintaining the convenience of the dob "push to".

Good luck and remember, keep asking questions if you're unsure!

[BC]

I'm overwhelmed by the the responses, thankyou all for your advice. To answer a few of the posts - I found links to this from er...um... on another forum where no one responded to my question. No, I don't have plans for astrophotography at this stage, my attraction to the EQ mount was more based on the fine control by hand. This is based on having never seen a Dob, let alone used one. I certainly plan a trip to Sydney to the shops soon. Stringscope, the info about the Canberra dark sky night is great, I'll contact you separately. It would be excellent to actually see the gear instead of reading about it. I can even compare the skies and see if I really have "dark sky". eg I can see with the naked eye that there was "something" at the bend in Scorpio's tail, which I could then see with my binoculars and identify as 6231. I have been enjoying immensely an old pair of Gerber 20 x 80 binoculars on a tripod I picked up 2nd hand. There's certainly plenty to see.

I really hadn't considered going to 10" as some have suggested. I also hadn't thought that an 8" on an EQ mount would be more heavy/awkward than a 10" Dob. I assume that I would be better off with a fan on a 10" due to our large daily temp differential. Add to that the nice Crayford focuser and suddenly I have a GS 10" premium Dob. See, I've been reading madly.

Your thoughts have been much appreciated

Thanks,
BC

[mch62 (Mark)]

An EQ6 with an 8"Newtonian on it is not a heavy awkward set up .

You don't move it as one piece but remove the OTA and weights.
It takes only a minute to reset the EQ6 mount up again.

I don't see Dob owners moving the whole lot as one piece when going to star parties, they come out of a car in 2 or more pieces
This depends on the size and design of coarse.
At home they use trollies of sorts to move the whole scope from storage.
You can do the same for an EQ mount if need be and i use to do just this with a simple wheely bars set up.

I use my EQ6 as my travel scope now for going to star parties and find that I am set up in only minutes , just as quick if not quicker than a Dob owner

As far as ease of tracking, if your only doing casual viewing no need to do a full polar align.
A compass and azimuth adjustment will take about a minute to do .
This will track good enough for visual and web caming and keep an object in the FOV for may be 10 minutes or more at high powers.

For a permanent pier set up a drift align will have it tracking for longer than this.

Dobs are great and have there place in astronomy but if your wanting to do more than what a Dob mount can do as you have stated don't be put off by the Dob owner who can't fathom the EQ mount.

It amazes me that every time some one states they want to track an object the Dob owners jump in and crucify the EQ mount as being too hard to use.
If you can't understand it don't knock it.


As far as the Go-to guys with the SCT setting up , that will depend on there experience level with there particular equipment and i have seen them set up in very short times as well .

Standard EQ mounts are not rocket science and have been around a lot longer than Dob mounts.
Sorry , I suppose the very first scope where on a sort of Dob mount (simple Alt Az mount)
Progress????

A Dob is just an economical way to get to view the heavens with the biggest aperture possible at the expense of a tracking mount.

Large Eq mounts do become very expensive and will cost a lot more than the OTA but the EQ6 gives the amateur an economical way to start to enjoy not having to continually push the OTA to keep objects centred .

I have been able to show many people more objects in a night due to not having to continually get back to the scope and re-center the object every time the next viewer lines up for a look . When i say many I mean at school nights like 30-40 viewers.
Now that would be fun having to re-center the object each time and hope they don't lean to much on the scope.

Have a quick search on the web for all the Eq Dob platforms modifications and kits and
Go-To kits that are out there for the Dob owner who wants to have that for which an EQ mount gives standard.

I don't knock the Dob mounted scope and have said many times before they have there place just the same as EQ mounts and Go-To mount have theres.

Mark