I stumbled across this because I am going to take a look at the collimation of the now semi-retired SP-C102 as I was having issues with the images at high power. The old refractor might be out of collimation or simply suffer from rough surface. I will find out soon enough. With the weather not conducive for observing for a few days (or is that weeks?) it might be time to take a look at some maintenance issues with the old scope.
Of course, I forgot "how to collimate" a refractor but I found this resource, Refractor Collimation and I just picked up a simple collimator to do it. So I will see just how far off the collimation is.