Quote:
Originally Posted by Regulus
That looks excellent Paul. Beaut star colours!
Why is the secondary rotating at all? Even if the spider isn't 'stiff', where is the force that moves it coming from? Is the tube flexing?
Sorry, just curious, and I hope it is an easy to fix proble.
Trevor
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Trevor, there is no tube flex (truss system) but the secondary is very large on this scope. Any scope with this from f5 down has a large secondary. Quite a few people who have used Newtonians a lot have advised that the secondary assembly can twist slightly under gravity (rotates) at certain angles in the sky. That very slight twist is totally unnoticeable when viewing through such a telescope but is clearly evident when you are imaging. Stability of the secondary in the alignment is paramount. I think I have stopped the cage from moving, but not the secondary itself. So I either need to extend the spider veins to a higher angle or provide a counter weight extending out from the assembly forward of the secondary opening. Most agree this is the best method to fix the problem. In any event I will report this to GSO as a suggested fix for this scope.