The rules/equipment specs have a requirement: the light intensity at all places on the playing surface should be at least 520 lux, which is 520 lumens per square meter. I got a lux meter on Amazon -- about $30. The local room is 160 lux at the end rails, and that's definitely not enough.
You're part of the rules. Those specs are all antiquated. There are typos all over the pocket sizes. For decades the pockets in the rules didn't reflect competition tables. I wouldn't trust anything in the rules for the light as far as I could throw a Gold Crown 4 table light.
Now, if a light company today hung their light at 6" increments over a wide range above the slate, and we had a subjective and objective measurement of how it lit the table, how it bothered or did not bother players eyes, how it bothered or did not bothered spectators eyes, we'd have something worth a damn.
