10 inch dob and 12 inch comparisons

[vindictive666 (John)]

gday everyone


i was wondering if anyone can tell me where i can find out a detailed comparison between the 12 inch and 10 inch dobs plse ? apart from the obvious mirror sizes

what i would like to know is what the actual observing comparision may be?

is the extra 2 inch a big difference ?

any help appreciated

[Saturn%5 (Graeme)]

G'day.
Im no expert but have been told it comes down to light gathering power which is worked out like this.

10" 10x10 = 100

12" 12 x12 =144.

Sorry i have no other link for you but im sure others will be able to help.I have a 12" gso dob and have also looked in the 10" and well just maybe a slight difference between the 2.

[vindictive666 (John)]

pardon my ignorance whats a gso dob
is that a particular brand name or something ?

[Saturn%5 (Graeme)]

Hi yes it is a 12" Guan Sheng Optics Dobsonian scope, also has other names like southern cross, bintel , hardin and many more hope this helps you.

[vindictive666 (John)]

thanx for that

i tried an google search and it came up with a site in germany
that sells an 12 inch gso dob with an split tube as option, that be cool, (if you could buy em in australia) i wouldnt mind paying a little extra for the facility to split the tube
it would make it easier for me to transport the 12 incher

[iceman (Mike)]

I've read that 12" is xx% more light gathering than the 10", maybe it's that 44% that Graeme suggested above, so obviously it makes a difference..

How much difference when you're at the eyepiece, will be up to the individual I suppose as everyone's experience may be a bit different.

But you do have to think seriously about portability - not only is the 12" a bigger and heavier mirror, the OTA is longer and bigger, the base is bigger and heavier, and of course, the cost is more.

My 10" is just on the side of portable for one person, I wouldn't want it too much bigger if I still wanted to be able to transport it in and out of the house by myself, or try and put it in the car.. the longer OTA and bigger base of a 12" just wouldn't fit in my car.

So you need to take all that into consideration, not just what extra faint fuzzy you might see in the 12"

[vindictive666 (John)]

thanx for the reply

transporting shouldnt be a problem ( I hope) as at the moment i am driving a mitshi pajero lwb

so the only trouble i might have is in setting one of big fellas up ?

as far as moving it ive also got access to an fridge trolley(might not be a good idea) or i was thinking on a wheel barrow sort of thing as shown on this pic (plse lemme know if the pic doesnt show?)

[iceman (Mike)]

I use one of the fridge trolley's for my 10" (see here)..

For a 12", the base is bigger so you might need a bigger footprint on the trolley to be able to sit it under enough of the base and not put too much strain on the welding..

[Saturn%5 (Graeme)]

Hi Guys.
Well you seem to be covering most bases now, My 12" is a bit big but i still manage to get it out in the back yard for those great nights of seeing (well when i get my mirror replaced) .But the shop has just emailled me and my new mirror is ready .

I wish i had gone the 10" but i will just have to suffer with the 12 so what ever you do get make it as big as you can afford.