Once the secondary is collimated, the next step is to align the primary mirror with its tip/tilt adjustments. When done properly, the rings from the Howie Glatter laser will be perfectly concentric with the secondary shadow. The pattern you see here is the one I got straight out of the box. I can't see any need to adjust! Impressive!

The large ring on the outside comes from the edge of the secondary baffle - diffraction - and is probably because I have the laser many inches inside the focal plane. It disappears when I manually (and shakily) move the laser out closer to the focal plane.