Help needed - which Dob?

Darth Wader (Wade) · #1 14-05-2009, 04:41 PM

Hi all
I got my beloved Skywatcher 70x900 refractor for Christmas last year and I've gotten every penny worth out of it so far, getting it out every time the sky is clear and moonless. I've really gotten into this hobby over the last 6 months and now I'm itching for a bigger scope. I don't track objects and I'm not imaging yet, I'm more of a point-and-go stargazer at present so I thought a dob would be the best thing for me.
I've checked out the Andrews Communications website and seen that a decent 10" collapsible Skywatcher can be had for $799, with the 8" version at a mere $399. I'm leaning toward the 8" based purely on pricing, but if I could manage to scrape together the remaining $400 I'd easily go for the 10". What I want to know is whether or not there is much of noteable difference in viewing between the 8" and 10" - basically, is it worth me spending the extra $400 on 2 inches of aperture, or is there more to it than that. At the moment I use my scope only in my backyard but I would use a dob at dark sky sites occassionally when I join my local Astro club next month.
Cheers
Wade

erick (Eric) · #2 14-05-2009, 04:57 PM

I wouldn't spend $400 more to go from 8" to 10". 8" is a great way to learn, easy to handle and transport, and the views far exceed what you have now. Gives you a chance also to take your breath and acquire some better quality eyepieces while you build up to the next step. Which, from 8", is probably 12" or, dare I say it, 16"!

ngcles · #3 14-05-2009, 05:02 PM

Hi Wade,

I'm biased and a bit of an aperture junkie (and an eyepiece junkie too) but if it were my choice I'd go for the 10". Choosing a telescope is a very personal thing so really it's up to you and what qualities you value most. Money -v-Aperture -v- Portability.

Yep, I know it's dearer but the way to look at this is that the 10" collects 56% more light than the 8".

That means that for any given object, the 10" will produce a 56% brighter image. You will resolve more (and see more) globular clusters, you will see many more galaxies and you are more likely to see some detail in the brighter galaxies and PNe.

As for the planets, unless the seeing is exceptional, the image in the 10" will be brighter and if the seeing supports it, you can use a bit more magnification without the image becoming noticably dimmer. On really top notch nights, the 10" will show a bit more detail over the 8".

On the other hand, the 10" is somewhat bigger, so if bad-backs and portability are an issue, you might well see it differently.

Either one will prove a real eye-opener for you because they are both so much bigger than a 70mm.

In the end it boils down to this -- the best telescope for you is the one you will use the most. Which one do you think you are most likely to use the most? The one that shows more and brighter but is a bit more costly and heavy (10"), or the one that is a little cheaper, shows less but is easier to move around and store (8")?

Good luck with your choice!

Best,

Les D

gmbfilter (Geoff) · #4 14-05-2009, 05:03 PM

Always think bigger!
There is a big difference between between an 8" and a 10"
12 or 16 even better still! Absolutely worth saving for worth saving for!
Collapsible dobs are handy if space or transport is an issue
When in doubt remember aperture rules OK

astroron (Ron) · #5 14-05-2009, 05:16 PM

Wade the short answer to this,
basically, is it worth me spending the extra $400 on 2 inches of aperture, or is there more to it than that. At the moment I use my scope only in my backyard but I would use a dob at dark sky sites occassionally when I join my local Astro club next month.
Cheers
Wade
is Yes,as Les said you will get more "Bang For Your Buck"
one of the pertinent points that could change things is portibilaty,other than that I would say go for the 10", you won't be disappointed

Chippy (Nick) · #6 14-05-2009, 05:33 PM

I'd say you can't go wrong either way. If you can get the 8" now versus saving for the 10" I'd be inclined to go that way. You will be able to sell the 8" without much loss to upgrade to a 10" down the track. The 10" would be a bit better, but the 8" is no slouch!

That seems a very good price for the 8" BTW - assuming all the accessories are the same I'd snap it up.

Rokketboy (Jared) · #7 14-05-2009, 05:40 PM

$399 for an 8" Dob. Tell me where and I will buy one with you

Im in the market for an 8" Dob as well. I was looking at a 10" but I think the 8" is a good compromise between aperture and portability for me.

toryglen-boy (Duncan) · #8 14-05-2009, 07:21 PM

aperture fever is a cruel mistress, you know as soon as you see something through the 8" you will be thinking "i wonder what this would have looked like through the 10"

i have a 12" but have plans to get a 16" in the very near future. In truth the 8 is a good cornerstone, and the starting point of many an amateur, and Eric raises a very good point when he says that the images from it will far surpass what you will see now, that said, and please dont take this as nasty, but anything pretty much will far surpass the views from a 70mm refractor, dont get me wrong, nothing wrong with it, and i am sure its a quality instrument, although in its current guise its probably limited to the the bright planets, and the brightest DSO's

Buy what you want. its that simple. if you want the 10, then buy the 10, if it means a few more weeks waiting, then so be it. Have a look in the IIS classifieds there are always great bargains in there, and i have yet to see anyone on here sell a scope that wasnt absolutely loved and nurtured to death, so you can be assured of not buying junk

Batfink (Peter) · #9 15-05-2009, 09:45 AM

Quote:

Originally Posted by Rokketboy

$399 for an 8" Dob. Tell me where and I will buy one with you

Im in the market for an 8" Dob as well. I was looking at a 10" but I think the 8" is a good compromise between aperture and portability for me.

Hey I'm in Newcastle as well, maybe we could make it a day trip and go to Andrews Communication, I think they are in Craystanes, save postage, although there's petrol, but at least we'd get it up here in one piece.

Peter.

PS I have just checked Andrews web site and it seems that the GSO 8" Dob is no longer available for $400, they are only showing the Super Deluxe version for $600.

TJD (Trevor) · #10 16-05-2009, 01:22 AM

Quote:

Originally Posted by Darth Wader

Hi all
I got my beloved Skywatcher 70x900 refractor for Christmas last year and I've gotten every penny worth out of it so far, getting it out every time the sky is clear and moonless. I've really gotten into this hobby over the last 6 months and now I'm itching for a bigger scope. I don't track objects and I'm not imaging yet, I'm more of a point-and-go stargazer at present so I thought a dob would be the best thing for me.
I've checked out the Andrews Communications website and seen that a decent 10" collapsible Skywatcher can be had for $799, with the 8" version at a mere $399. I'm leaning toward the 8" based purely on pricing, but if I could manage to scrape together the remaining $400 I'd easily go for the 10". What I want to know is whether or not there is much of noteable difference in viewing between the 8" and 10" - basically, is it worth me spending the extra $400 on 2 inches of aperture, or is there more to it than that. At the moment I use my scope only in my backyard but I would use a dob at dark sky sites occassionally when I join my local Astro club next month.
Cheers
Wade

if you get the 8" you would have wished you got the 10" and if you get the 10" you would be wondering why you just spent so much on a scope

GrahamL · #11 16-05-2009, 07:56 AM

Quote:

I'm not imaging yet

I had a 10" for a couple of years and found it great... depending on your car and passengers the base and tube do take up a bit of space.
An 8 and 10 from a dark site are both very capable scopes and can give a lifetime of enjoyment...Should you want to get into imaging
the 8" can be quite easily and affordably .. "not sure affordable is a word that keeps company with astrophotography for long

"... mounted to get you started.. while still being able to swap back to dob mode to briefly escape the evil clutches of the dark side of the force.

good luck ,, seems your wife made a great choice coming in
here at x-mass

Darth Wader (Wade) · #12 16-05-2009, 05:50 PM

Thanks for the replies everyone. I've decided to aim for the 10" based on several recommendations. It may take a little longer to get the money together but in the end it will be worth it. The next step up from that? perhaps a 20"! We'll see what the future holds.

Quote:

Originally Posted by toryglen-boy

please dont take this as nasty, but anything pretty much will far surpass the views from a 70mm refractor, dont get me wrong, nothing wrong with it, and i am sure its a quality instrument, although in its current guise its probably limited to the the bright planets, and the brightest DSO's

Hahaha, no offence taken! I agree with you 100% which is why I'm so keen to upgrade! I basically can't see any DSO's from my backyard and I'm really keen to see a bit more detail in the planets. That said, it has been a fantastic starter scope. Will be keeping it for the kids when I upgrade (hopefully as they get older they may take an interest in stargazing!).

Quote:

Originally Posted by nightstalker

good luck ,, seems your wife made a great choice coming inhere at x-mass

Indeed! If only she'd known what kind of monster she created!

Thanks again all.

Cheers
Wade

flearosie · #13 29-05-2009, 01:13 AM

nightstalker - can you please elaborate or explain how you can use the dob to take photos? I wasnt aware that this could be done, I suppose though it is rather a tricky thing to change mounts? Cheers

GrahamL · #14 30-05-2009, 05:07 PM

The solid tubes can be put atop an eq mount .. and put back on the dob mount when you wish .. havn't seen those collapsable ones as cheap as $399 yet ?.. .. and arn't sure if you could mount them as such .

cheers graham

dizzy2005 (Mike Diskett) · #15 31-05-2009, 09:57 PM

I recently upgraded from a 60 mm cheap refractor (actually a birthday present for my daughter) to a 8 inch reflector. (and thats why its been cloudy in brisbane or the last 3 weeks) 8 inch collapsible skywatcher.

I'm actually glad I didn't go for the 10 inch. (the alternative was a non collapsible 10 inch) The 8 inch is a bit of a struggle to get out of the house all in one piece and I tend to have to move it around a few spots around the garden depending on what I want to look at (trying to dodge various light sources).

The 8 inch is fantastic compared to the 60 mm (as you would expect), all though the cool down period can be annoying and I understand its a lot worse with a 10 inch.

For me a lot of the fun in astronomy is hunting down the objects, learning to follow star charts etc, (I found looking through other people scopes they have set up to look at something a bit of a disappointment even when its a $10000 scope) so I had a great deal of fun with the 60mm, and now with the 8 inch I've opened up a whole new set of objects I can hunt down.

Mike.

Darth Wader (Wade) · #16 09-06-2009, 02:04 PM

I changed my mind and decided to go for the 8" purely because it's all I will be able to afford for a fair while (another baby due in 5 weeks!

) but I've just checked the Andrews website and the 8" is now $499! Must have been a typo. Anyhoo just wanted to say thanks again to you all as you've been instrumental in my choice of upgrade. Next stop: dark sky sites!

Cheers
Wade

Chippy (Nick) · #17 09-06-2009, 02:36 PM

That's still a good price for an 8" brand spanka. You'll enjoy it!

bmitchell82 (Brendan) · #18 09-06-2009, 03:08 PM

a dob is easy to put on a eq mount

rings and a dovetail that normally comes with the mount

the 8 is a little easier to put up on a Heq5 mount that is a bit cheaper though a 10 needs a heq6. over all the 8" dob is a great little scope and will let you see heaps of things in a recent messier marathon with my friend and me (ive got the 10 he has the 8) the only difference with the viewing was the brightness. and a little more detail.

Good luck have fun!