Pics of GSO 8" F/9 RC scope...

[Starkler (Geoff)]

Originally Posted by toyos

Why would someone choose an 8" f/9 RC with 40-45% central obstruction over say a 5" f/7 APO refractor with a field flattener & zero central obstruction??

Or a Vixen R200ss with better quality optics at f4 with a Baader MPCC to correct the coma ?

[Gama]

Originally Posted by Starkler

Or a Vixen R200ss with better quality optics at f4 with a Baader MPCC to correct the coma ?

At this level, your starting to split hairs.
All scopes will perform very well, with no winners unless the seeing is extremely good.
This is going to be a decision the atmosphere and weather is going to make.

Like having 3 supercars all together for a race and its raining.
None of the cars will be able to reach its best performance, so you will have similar results.

If you cypher thru it on paper, theory or use computers and wave analysers then you will get definitive results. But unless its going into space, forget these reults and look at what is possible with human eyes and local atmosheric conditions.
The vixen with corrective lens's improves flatness and other abberations, the RC has none to start with, but you can add them as an option, and then its a whole new ball game again.
They will all have a near perfect view in your eye, and do some excellent imaging, so it boils down to how excellent do you want it, and will you notice the difference easily.

Theo.

[monoxide]

ill skip all the speculation till i actually see someone use one and post actual results rather than guess and compare it to whatever takes my fancy at the time.

toyos, i remember you saying your 6" refractor resolved better than your 12" newt, i dont know how seriously to take your comments on the light gathering power here?

i also cant see how an 8" f/9 scope is comparable with a 5" refractor either, widefield vs deep space? i dont mean to sound grumpy here but if your comparing imaging scopes they should atleast be close to the same focal length wouldnt you think?

like i said before though i dont know how people can make any comparisons until someone actually has one and uses it, i guess some people will always compare the 'knock-off' to the real deal and expect a lot more for less

for what its worth though, i think it will be an excellent scope that will perform very well plus its a huge step forward for amatuers to have these kinds of scopes becoming avaliable at an affordable price, even if they dont have theoretically perfect optics