The ultimate accessory kit also includes a small reflective dish that fits
nicely on the lamp. If you use it then you don't have to worry about any
light coming directly back into the light sensor. It also focuses more
light forward thus increasing the amount reflected back.
(...) I tried another light sensor I had, and it's readings were 670 around the rest of the room, and 655 at 9 inches. In other words, not only were the readings lower, but much less sensitive. You might want to search for your 'best' light sensor (...) (24 years ago, 9-May-01, to lugnet.org.us.smart)
