All Dobsonians the same?

meadowglen (Glen) · #1 25-02-2010, 01:23 PM

I have a teenage son who is interested in astronomy and has asked for a telescope for his coming birthday. After looking at various posts in the past, the GS 6” Dobsonian seemed a good choice. However when I contacted our local optical shop the salesman said they only had a Saxon 6” Dobs in stock, but this was just the same as the GS as all of the main telescope manufacturers, including GS, Saxon, Skywatcher etc obtain their lenses and mirrors from the same source. He said it did not matter which brand you bought, they were all the same, so just buy the 6” Dobs with the lowest price. Is this correct? Thanks for any clarification of this.

Paddy (Patrick) · #2 25-02-2010, 01:28 PM

Guang Shen, Saxon and Skywatcher are all good dobs these days. People I know with Saxons are very happy with them.

Satchmo · #3 25-02-2010, 01:32 PM

Quote:

Originally Posted by meadowglen

as all of the main telescope manufacturers, including GS, Saxon, Skywatcher etc obtain their lenses and mirrors from the same source.

Saxon is a locally branded Skywatcher and make their own optics in China whilst GSO is Taiwan and have their own optical manufacturing. The Saxon may have a Pyrex ( low expansion ) mirror so check on that .

erick (Eric) · #4 25-02-2010, 02:26 PM

"just buy the 6" dob with lowest price". Yes, pretty well Glen, but it is worth seeing which acessories they come with. Come back here with the list of specifications and accessories and we can comment further.

meadowglen (Glen) · #5 25-02-2010, 03:40 PM

I have asked the supplier for some more details. Apparently the telescope is fairly basic, just a finder scope and 2x1.25 Plossl lenses. The mirror is BK7 glass he thinks (he says Pyrex is no longer made).

Louwai (Bryan) · #6 25-02-2010, 04:02 PM

Glen,
My opinion is;

If the scope is for a young fella, and is his first scope, just buy the cheapest Dob. (Personally I'd go 8").
Who really cares what the mirror is made of or where it comes from. At that level they are all reasonably the same.
He will love it.
And you can bet your bottom dollar that he'll want a bigger one within a yr.

Once he's shown that it's more than a passing interest (assuming that he hasn't been into Astronomy for a good while) then go into the details in more depth & get a good quality scope for the next one.

B

erick (Eric) · #7 25-02-2010, 04:36 PM

Quote:

Originally Posted by meadowglen

I have asked the supplier for some more details. Apparently the telescope is fairly basic, just a finder scope and 2x1.25 Plossl lenses. The mirror is BK7 glass he thinks (he says Pyrex is no longer made).

Yes, mirror material isn't a significant issue. But you will find that if the package came with a dual speed focusser and a right-angle correct-image (RACI) finderscope, those little touches make it easier to use. Some suppliers add an additional eyepiece which can be useful. Some don't come with a cooling fan on the primary mirror which is also useful to have. Yet the price doesn't change that much for these little extras. Sometimes you pay a premium for the named brand when the unnamd brand, without the glossy paint finish, performs just as well optically and mechanically, but has these little extra options.

But that may mean ordering from an interstate supplier - then you have a shipping cost and you don't have a shopfront to walk into with questions or issues.

Let's at least check that you have seen all the shops accessible to you. OK guys and gals, which are the Adelaide shops that Glen can visit?

Liz · #8 25-02-2010, 05:13 PM

Hi Glen .... the 6" Saxon will be great!! Of late I have found Skywatcher/Saxon better than GS stuff

.... and a 6" will be nice and easy to manage for your son (hopefully), and still be able to see some great views of Moon, galaxies , nebula and some planets

mswhin63 (Malcolm) · #9 25-02-2010, 06:48 PM

Quote:

Originally Posted by erick

right-angle correct-image (RACI) finderscope

The first thing I changed on my DOB, if it has a Right Angle Finderscope that will be a big plus. Not that expensive to replace either.

For introducing the 6 or 8" would be a great choice and will be great for a grab and go.

Satchmo · #10 25-02-2010, 07:54 PM

Quote:

Originally Posted by erick

Yes, mirror material isn't a significant issue.

Not so significant on a 6" scope. Much more significant on a 16" .

stephenb (Stephen) · #11 25-02-2010, 08:59 PM

Hi Glen, A 6" Saxon, Skywatcher or GS Dobsonian is a great choice. If you can stretch the budget to an 8" Dobsonian, then even better, but don't stress about it. And don't worry about a lot of talk you will hear and read about mirror quality. Discussions on telescope mirrors are like audiophiles discussing which speaker cable is better for a surround sound system. 99% of amateur astronomers wouldn't know the difference if their mirror was from a Chinese/Taiwanese production line or handmade by an mirror maker. And that's fine because you just want your son (and you) to enjoy the hobby.

I would tend to look at the latest GSO dobs only because I like the improved altitude bearings (that's bearings on each side of the tube!) Saxon or Skywatcher may have caught up and improved theirs also. Andrews Communications have them with some good accessories which Eric mentioned, but you may also have a budget.

Don't go any smaller than a 6" however.

See if you can pick up Astronomy 2010 - the yearbook at Andrews, BinTel, or Quasar Publishing It's about $20.

Best of luck,

Stephen

norm · #12 25-02-2010, 09:09 PM

Hi Glen,

Welcome to the forum

. If you didn't know, there is a free program called Stellarium. Download it to help navigate around the night sky.

Cheers, Norm

stephenb (Stephen) · #13 25-02-2010, 09:11 PM

Good tip Norm! http://www.stellarium.org/

mswhin63 (Malcolm) · #14 25-02-2010, 09:21 PM

If you don't have a open source 3D Graphics on your computer Worldwide Telescope is a good program as well. http://www.worldwidetelescope.org

erick (Eric) · #15 26-02-2010, 11:28 AM

Quote:

Originally Posted by Satchmo

Not so significant on a 6" scope. Much more significant on a 16" .

Yes, I'll accept that. I also note:-

http://www.skyandtelescope.com/howto...tml?page=2&c=y

TheDecepticon · #16 26-02-2010, 11:52 AM

You have very little choice here in Adelaide. You can go into the city in Grenfell St to Adelaide Optical Centre and get ripped off and ignored and mucked around with problems and wait 6 months after you've ordered it and it still isn't in yet.
Or you can go to Optic SA on Henley Beach Rd and talk to Andrew, who is reasonably intelligent and interested, pay a bit more and walk away with something.
Personally, I don't shop locally anymore, I generally buy from Bintel in Sydney and wait the few days for it to arrive. If you want some help, PM me and I can help you over the phone or in person. I am an active member of the Astronomical Society of Sth Australia, if that helps.
Cheers,
Gray.

meadowglen (Glen) · #17 26-02-2010, 03:09 PM

Thank you everyone for your advice, it was very reassuring when making a decision about the telescope and to know there are so many other interested people out there. I will download some of the suggested software and also try to get to one of the Astronomical Society meetings. As for Adelaide suppliers - I have found three, the cheapest being a person called Matthew who I gather runs a small business from home. He has a 6" Saxon for $360, while Adelaide Optical has them for $369 and $440 from Optic SA, so I guess I will give Matthew a call.
Thanks again

Solanum · #18 26-02-2010, 03:18 PM

Quote:

Originally Posted by meadowglen

Thank you everyone for your advice, it was very reassuring when making a decision about the telescope and to know there are so many other interested people out there. I will download some of the suggested software and also try to get to one of the Astronomical Society meetings. As for Adelaide suppliers - I have found three, the cheapest being a person called Matthew who I gather runs a small business from home. He has a 6" Saxon for $360, while Adelaide Optical has them for $369 and $440 from Optic SA, so I guess I will give Matthew a call.
Thanks again

Ah yes, the famous Telescopes and Astronomy website. Have a look at his site and you'll be very confused. I and a number of others on this forum have bought stuff from him though and he's always been helpful and honest, so don't worry about his business being run from home.

V-Man · #19 26-02-2010, 07:59 PM

Quote:

Originally Posted by Solanum

Ah yes, the famous Telescopes and Astronomy website. Have a look at his site and you'll be very confused. I and a number of others on this forum have bought stuff from him though and he's always been helpful and honest, so don't worry about his business being run from home.

Oh Yes that website has to be just about the worst to navigate that I have ever seen. I hope you read this Matthew and take this comment on board.

FWIW there aren't many dedicated astro suppliers in Aus that actually have a shop front. The Aus market just can't support this. However I think that most of the "home based" or actually often small warehouse based operators are very reputable and can often beat the "big blokes" in both price and service. It pays to shop around, and it pays to put service in front of price (within reason)

It also pays to check that anyone you deal with is actually an authorised dealer for the brand you choose. Its easy to do, manufacturers have websites that list authorised dealers worldwide. If you do buy from an unauthorised dealer there's a very big chance that you will be on your own if you have a warranty claim.