I wanted to take a second and bring up one of the unsung heroes in the mini projector build and reiterate that the dichro bridge has for sale works extremely well at 520nm Actually the blue combine is excellent as well. I was able to measure the loss and for 57mw out I loose 0.56 mw so that's 0.98% loss. That's as good as many high performance first surface mirrors. The blue is about the same. So bridge many thanks!