SCTs are?easy to?collimate?because there is only one accessible adjustment - secondary tilt-tip.? Collimation aids are entirely unnecessary and of dubious value compared to star collimation.?Star collimation is very sensitive and precise, though it may take some time to develop an eye for assessing the?concentric placement of?diffraction rings (start with centering the shadow).?
A potential problem with most collimation aids (incl artificial stars) is that they require?collimating in horizontal position. That?can easily result in miss-collimation?when sky pointing, due to?flexure (esp of the primary). This is more likely in larger scopes but can occur for any scope.
Save your money for a sexier gadget.
Stan
