Dobs or Refactors

Hi all,

as i posted before im seriously thinking of changing scopes im just wondering which is better Dob or Refactors? I was using a celestron CGE 1100 XLT last week iv kinda fell for it what a scope.... :shock:

whats the pros & cons of either

hi,
I'd only consider a refractor if its high end, a dob will give you a bigger aperture so will show nearly all objects better, although some of the bigger dobs are not very portable.

Hi dave,

would an 11" be regarded as high end? Ye i got to use an 8" dob last week looking at saturn i was very impressed to be honest

Refractor VS reflector is an age old agrument, there are those who swear blind by a refractor and those who wouldn't use anything but a reflector, it's down to a matter of taste, both have their merits and their drawbacks.

On a personal note I'm a refractor nut, I just love them, I use either an 80mm or a 127mm lens, the 80mm is a great grab n' go scope, the 127mm is for more serious observing.

I have used a dob and an SCT in the past and enjoyed both and I gravitated to the refractor.

IMHO these are the pros and cons of both, and I am willing to be shot at for my opinions.:

Refractor:
Pros: Clear aperture lens, ease of mounting, no colimation and a classic telescope look.
Cons: Price, the larger the lens the higher the price, for an APO the price curve is very steep. On a standard tripod an observer could be almost lying on the ground in a longer focal length scope.

Dob:
Pros: Price, for the price of a 120mm APO a dob of huge aperture can be purchased. Wide field of view, a large mirrored dob gives stunning views of the night sky. No need to learn about polar aligning, the Dobsonian box is a masterpiece of simplicity.
Cons: Weight, a 12" dob is an unwieldly piece of equipment and can be difficult to get set up, bigger mirrors can mean bigger problems. This can be solved by getting a truss pole dob.
Height, the bigger the mirror the taller the scope and looking at the zenith will require a step of some description.
Collimation, a mirror will reguire regular collimation to keep the light path right.

You have an 8" dob, this is a good sized aperture and moving up to an 11" will not provide a huge difference in seeing.

A CGE 11 is an SCT, this will have a longer focal length and you are going to have to learn the fork mount, which is not too difficult.

If you are looking for wide sweeps of the sky then a faster dob, say f/5 in the 14" bracket could be what you are looking for. If the money is there, then go for a bigger mirror in a truss pole design, it's lightweight and once mastered can be set up quickly.

Hi dave,

would an 11" be regarded as high end?

It certainly would be high end, with scopes like this and bigger its a matter of how much of a scope are you willing to haul around and how much you are willing to pay.
In my book, there is no such thing as a scope thats too big.

The worst thing you could do is buy a scope with a view to getting a bigger one in a few years time, it costs you more in the long run.

Thanks for that paul