–Took the Polaris apart again and eventually found a clog in the last possible place: a small right-angle tube that sends a jet of water to turn the paddlewheel. (1) The clog shouldn’t have gotten that far, what with all the filters. (2) It was several small bits of redwood debris. Still, I would have thought that the final huge filter would trap anything bigger than a few microns. (3) The tube should have had a smooth curve, not an abrupt right angle. Anyway, after a futile attempt to get it running right, I put the bottom back on, which holds the idler wheel (d’oh!) and found a website that went step-by-step in showing how to properly install and adjust the wheels. It will run right tomorrow, guaranteed.
–Checked the C-Lux on center-weighted, multi-area and spot metering. Multi wins out, at least for side-yard pictures in the sun.