Not bad. I can't tell where the photocell is and I think it must be behind the main lens of the lamp. But they work as they should, on at dusk and off at dawn. Even under a canopy, and one of them is somewhat blocked by a drainpipe, where they are in a dark place, they still respond acceptably and don't show up ridiculously early or stay ridiculously long after sunrise. in comparison, of course. Every photocell light I've ever had stays on for a while after the sun has risen far enough to see and doesn't require an outside light. Let me just say they are no worse even if they are in a less than ideal location for photocells to work. Brightness is good for a 60 watt equivalent. And yellow light is good for illuminating bugs. Not too dark to be amber but definitely a nice solid yellow. So I'm very happy with them so far, I hope they last a long time. If they prove durable, I'll buy a few more. If they die unacceptably soon, I'll let you know.