[The_bluester (Paul)]

Hi Ken, a version of that showed up on Facebook for me this morning. In the case above of me fiddling with spacing on my SCT I certainly had an example of the second image.

For anyone else who does not know, the first one with the stars radiating away from the center of the FOV indicates spacing between the reducer and camera that is too small, the second with the radial arcs is for it being too large.