Dob advice

andromeda · #1 27-10-2007, 11:54 AM

Hi!

I've been dancing around the idea of getting a scope for about a year now. I've purchased some 10x50 binos, downloaded some star charts, picked up some books and gone out on a fair few viewing sessions.

It's time for me to bite the bullet and go buy a telescope.

I'm thinking a GSO Dob is the right scope for me but I'm unsure on the size. I want a size that is easy to carry around but still want some spectacular views. I was thinking a 10" but maybe this is a little too big? I've been drooling over the 12", but that thing is a monster! I feel that if I need to use a trolley to lug the thing around I'll lose interest pretty quick (sigh factor)

.

Maybe an 8" is the way to go? Price isn't really an issue. I just want a good beginners size!

Thanks!
(Also, first post!

)

mill (Martin) · #2 27-10-2007, 12:22 PM

Welcome to iis andromeda.
A 10" dob will be a good scope and will last you for years to come.

iceman (Mike) · #3 27-10-2007, 12:40 PM

Hi there and

to IceInSpace.

It sounds like you've been doing your research, great to see. An 8" dob is perfect for a beginner, but the 10" will be better if you can move it around. Putting it on a trolley really a big deal, it's quite easy to move it around like that. The extra light gathering is just what you want - and if you decide later on astrophotography of the planets or moon, (or DSO's with a bit of adjustment), you can throw it on an EQ platform or EQ mount to get tracking.

You can get something like an Argo Navis (DSC's) to find the objects - really easy to use and will last you forever.

Keep asking questions!

Solanum · #4 27-10-2007, 12:45 PM

I have a 10" and it's easy enough to shift around with a hand-trolley. The OTA is over 20kg and the base is fairly heavy plus the assembled scope is extremely awkward, so It is a BIG strain on the back to carry it by hand more than a few yards. I pretty much stick to the back yard, but it would go in an average car easily enough (without many passengers!).

The 8" is definitely more portable, but it's light gathering power is quite a bit less, though you can say the same about the difference between the 10" and 12".

One other thing to consider is the f-ratio. I assume the 8" is higher than the 10". I do find that with some eyepieces (hey, I can't afford televue!) the effect of coma means the outer area of the eyepiece can be quite stretched.

A couple of other bits of advice, get one with the 10:1 fine focuser and right angle finder, they make a big difference. Also splash out on a Telrad ($79 from Bintel). The Telrad is easier to fit on the dobs (unless you don't mind removing the finder) than similar red dot finders and makes pointing the scope a doddle compared to crouching down and trying to do it by eye..

mrsnipey · #5 27-10-2007, 03:12 PM

Hi there

.

I recently bought a 12" from Mikezoom and I love it. Without a doubt
the best purchase I've ever made.
I added some castor wheels to the base of the dob and removed the
rubber stoppers and it's really easy to move it around.
My wife can push it around with one hand. She's only 5'2".

My point is that even though the 12" is big, even with the castor
wheels on the bottom I still have to bend over to look through the
eye piece when it's pointed at zenith. (I'm 6ft). So it's not that big.
I don't find carrying it that much of a problem either. It only gets
tricky when you're trying to squish through a doorway.

I have a 4.5" newtonian on an eq mount which is easy to carry out
and pretty easy to polar align but when I look through it I keep thinking
to myself "Man, if I had my 12" dob out I'd be able to see heaps more."
So now I hardly ever use my 4.5". Unless my daughters want to have a
look too.

I say go for the biggest you can comfortably afford. You won't be
disappointed.

Having said that, I don't intend to travel anywhere with my dob, except
my back yard. I certainly wouldn't be able to fit it in my car anyway.
I've got a Holden Astra and there's no way it would fit in there.

Good luck.

astro_nutt · #6 27-10-2007, 03:51 PM

If you want more portability go for the 8"..it'll fit nicely in the boot of small sedan and very quick to set up..but if you want more light gathering power..then go for the 10"..and to help cart it around..make an insert from the original box and secure this to a 2-wheel hand trolley with pnuematic tyres..secure the tube with a couple of bungee cords and you're away!!..works well for me...
Whatever you choose..enjoy!!!
Cheers!!

ngcles · #7 27-10-2007, 09:56 PM

Hi Andromeda,

I'll try and be brief but most importantly, the best 'scope for you is the one that you will use the most.

Human nature dictates that the more difficult an undertaking is, the less likely we are to do it.

Get the 'scope you think you are most likely to use the most, but having said that ...

The 10" gathers about 50% more light than the 8".

The 12" gathers about 45% more light than the 10".

More aperture means a brighter somewhat more detailed view and many, many more fainter objects become visible. The difference between 8" and 10" large, and 8" to 12" is _thumping_.

Does it have to be portable so it can be taken elsewhere or will you only observe from home? Will it fit in the car? How much room have you got to store it?

The 10 and 12" versions are not that much bigger to store. They are heavier but not _that_ much harder to move around (if you do it in two parts, it's easy). The eyepiece height of the 8" dob can be a bit low to be comfortable for adults

Best of luck with your decision and enjoy the new 'scope.

Best,

Les Dalrymple
Contributing Editor
AS&T

Paddy (Patrick) · #8 27-10-2007, 10:25 PM

Hi Andromeda,

Nothing that hasn't been said before, but on reading your question my thought was also whether you plan to use it only at home or to transport the scope by car. If the former, I find it very easy to handle my GSO 12" on a trolley, (with a strap for added security). But I wouldn't want to be moving it to get to a dark site very often.

Whatever you get, I reckon you'll have a lot of fun.

Patrick

ballaratdragons (Ken) · #9 27-10-2007, 10:59 PM

I don't think my 12" is heavy! But awkward.
The 8" is waaayyyy light. The 10" is about right.

Even though the 12" will give you much better views, the 10" is an easy scope to carry around. And fits in almost any car. The 12" is a bit big for most cars. It fits in my Falcon but only just.

If you can get to a shop, try the weight of the 10" and I think you'll find it very managable.

My 11 year old son carries the Clubs 8" around, so that gives you an idea.

Alchemy (Clive) · #10 28-10-2007, 07:28 AM

Quote:

Originally Posted by andromeda

Hi!

It's time for me to bite the bullet and go buy a telescope.

.

Price isn't really an issue.

Thanks!
(Also, first post!

)

(Cut down your post to the essentials there).

you could try the meade truss tube version, more portable then a solid tube, kinda snazzy looking too. i dont know how the collimation stands up when disasembling etc, but you will need to learn to do that anyway......that would be my choice. go as big as you can afford!!!!

Tamtarn · #11 28-10-2007, 10:49 AM

We move our 12" around on a trolley and it's quite easy.

The smallest I would go would be a 10".

After all when you buy a scope you want the best views possible.

If portability is an issue then as Al has said above have a look at the Lightbridge.

GrahamL · #12 28-10-2007, 01:18 PM

Quote:

price isn't really an issue

there is that 16" lightbridge to look at .. it does break down and I sure could convince me ..it would make a half decent
first scope if I was in the market

andromeda · #13 28-10-2007, 03:05 PM

Wow! Thanks for all your replies guys!

Quote:

Originally Posted by ngcles

Does it have to be portable so it can be taken elsewhere or will you only observe from home? Will it fit in the car? How much room have you got to store it?

I will do much of my viewing from my backyard but would still like the ability to cram it into my '85 Toyota Camry hatchback and head for some darker skies, so portability is pretty much essential.

Having said that, seems like the way to go is "as big as I can afford" and I think the Meades are definitely worth looking into. 16"? Whoa! That is BIG. Hmmmm

I'll be heading into Bintel Melbourne sometime very soon, so I can have a hands on look at everything... but I have a feeling I may be walking out of there with a 12".

Thanks everyone! Any more advice/experiences are much appreciated!

-andromeda

mill (Martin) · #14 28-10-2007, 03:13 PM

There is an 10" dob for sale in the for sale section

ngcles · #15 28-10-2007, 03:46 PM

Hi Andromeda,

You may be interested to know that I have a friend who drives an early 90s Daihatsu Charade, that he fits a 16" lightbridge into with little diffiiculty once the back seat is folded down. His tripod, parallelogram bino mount and 25x100s still fit in alongside it.

There is a guy in France who fits a 22" f/4 ultra-light into the same make and model ...

Best,

Les D

astronut (John) · #16 31-10-2007, 08:01 AM

to IIS Andromeda, since price is not a barrier and you are considering a 12" why not try the Meade Lightbridge 12".
Cost is $1499 about $500 more than the solid tube, but with the added advantage that it breaks down to small pieces for transport.
I can easily fit it into my 89 Ford Laser.
Collimation takes me only a minute.
The optics in the solid tube scopes and the LB's are the same, ALL made by Guan Sheng!!
Enjoy the selection process!!

andromeda · #17 31-10-2007, 02:08 PM

Hey everyone,

Thanks for all your advice. I've gone out and brought the 12" Lightbridge and already had a viewing session in my backyard with it!

It's an awesome scope! Thanks everyone for guiding me in the right direction.

Now comes all the accessories. I columnated it pretty well by eye but will NEED a laser columnator. Bintel were sold out.

I will need some recommendations on some good eyepieces soon too, but thats a thread for another day...

Anyway, this site has been great for a newbie like me! I will be back here often.

Cheers
-andromeda

erick (Eric) · #18 31-10-2007, 10:17 PM

Quote:

Originally Posted by andromeda

.....but will NEED a laser columnator. Bintel were sold out.

Here you go! http://www.iceinspace.com.au/forum/s...ad.php?t=25379

Or, for a very good option, read here:- http://www.iceinspace.com.au/forum/showthread.php?t=24955

astronut (John) · #19 01-11-2007, 07:56 AM

Congratulations, on the new scope.
After you've had a play with it, I recommend that you replace the primary springs and the primary and secondary collimation knobs.
The stiffer springs will hold the collimation in place much better than the soft "original" ones.
After you've "battled" with the original collimation knobs you'll know why you need the new ones.
You can buy the set of springs and knobs through Bintel (these are Bobs Knobs) or you can get slightly different looking knobs from www.Astronomy-Shoppe.com in the U.S. The price is about the same, I bought these.
Del time is about 1 week.

Omaroo (Chris Malikoff) · #20 01-11-2007, 08:25 AM

Quote:

Originally Posted by erick

Here you go! http://www.iceinspace.com.au/forum/s...ad.php?t=25379

Or, for a very good option, read here:- http://www.iceinspace.com.au/forum/showthread.php?t=24955

Andromeda - congrats on your purchase

As Eric says - the laser collimator I recently bought will suit your application right down to the ground. The reason is that you have a truss scope - and you can see the laser's barlow screen and adjust your collimation from the base of the unit without having to go back and forth to look down a tube. Very nice! Do as Astronut says and get yourself some Bobs Knobs and using them coupled with the astroSystems laser unit you'll be accurately and easily collimating yourself in a couple of minutes.

Cheers
Chris