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View Full Version here: : 8" Reflector from Aust. Geographic


jakob
03-11-2006, 11:35 AM
I am interested in this Scope as a an addition to my 4" Mak.
I'm told its origin is Hongkong and is f=750mm. I like the EQ mount with the built in alignement scope.
How would this compare to a 8" Dob?
:shrug:
Any comments?

iceman
03-11-2006, 12:04 PM
Sun filter!?!?!?!?!?! Not good.
Is that $699 australian?

It looks like a very short tube - what's the stated focal ratio of the mirror? Works out at like f/3.5 or f/4 at the most?? Very fast! Very bad on eyepieces, very difficult for collimation.

The mount is also hardly heavy duty - it will probably be quite wobbly.

Without seeing it in the flesh it's hard to say really, but I would think the 8" dob is much better value for money, and at f/5, much easier to use.

janoskiss
03-11-2006, 12:08 PM
I would not buy a telescope from Aust. Geo. They do not have a clue about scopes. This one looks very much like the cheapies you see on ebay: flimsy mount and tripod, poor finder, focuser, accessories. And if it really comes with a Sun filter, it's almost certainly a screw-into-eyepiece type, which is a real worry! If you want this style of EQ mounted scope you should consider a GS or Synta 8" f/4 on an EQ5 mount from Bintel/Andrews/AOE/Myastroshop...

Re Dob vs this style scope, an 8" f/6 Dob will almost certainly outperform an 8" f/4 Newt, because it's easier to figure a slower mirror and central obstruction will be smaller.


Mike, the 8" GSO/Synta Dobs are f/6, so even more forgiving.

acropolite
03-11-2006, 01:23 PM
Ditto what the others have said, go for the dob.

netwolf
03-11-2006, 02:17 PM
Looks like the one up for sale on Ebay at the moment, it used to be branded as Optex, same also sold under other brand names. They have also come up now and then on Graysonline auction sites. The one on ebay seems to have no Collimation screws on the secondary either, perhaps its covered by a cap.
Focuser is 1.25" only. I like the 8" newt's I think in hindsight I would have been better off with a 8" f/5 dob, instead of my 10" especially now that I am looking for a GEM mount for it.

Regards
Fahim

Regards
Fahim

janoskiss
03-11-2006, 02:41 PM
Hmmmm, the grass is always greener... :o I have the 8 and 12" GSO Dobs and I'm thinking I might be better off with just one 10" Dob. :lol:

rmcpb
03-11-2006, 02:43 PM
Don't touch it with a barge pole, or anything else for that matter. It would be a continual source of frustration and disappointment.

As you have a tracking scope already go for the DOB, it come highly recommended from many of us here at IIS.

jakob
04-11-2006, 08:49 AM
I will stay clear of it.
It looked attractive at first sight and with the offer of 20% off!
That probably says it all.

I'll keep on track for the LB 12":P

ving
04-11-2006, 10:09 AM
looks like an optex :confuse3:

anyhow, as the above have stated.... you are better off with a 8" dob or a eq5 mounted 8" f5. the mount will be more stable (probably, or at least of better build).