[Marko of Oz (Mark)]

Hi all,
I've read reams of articles and how to's on collimation for Newt's including the ones on IIS and they all seem pretty vauge on one point in particular and that is the part where you "rotate" the 2ndary on its center bolt till its shape looks round through the focuser, not oval.

Ok,that sounds easy enough, but there's a lot of margin for error there between what looks oval and what looks round. (to my eye at least) So my question is:

Is there an accurate/easy way to do this or is near enough good enough for this part of the collimation?

I have a laser collimator(collimated) and an Orion combo sight tube cheshire tool to work with.

cheers

Mark