Thanks, I really don't have a college level understanding of optics, but I keep trying to understand them and apply the findings to my hosts. My expanders aren't anything more than rough seat of my pants creations using lenses i find on ebay, none of the beams have correction to even the size of the slow axis to match the fast which without it produces a rectangle output beam instead of a spot, but I'm going to try that soon. I recently asked Ehgemus what his mill setup is, no answer yet. He did a fine job on those threads, wish I had a video showing how he makes these.