John,
Before you give up on the screw in sensors:
1) Is the sensor portion of the device adequately shielded from the light from the bulb controlled by the sensor? It is possible that the sensor is causing a rapid flicker as it attempts to constantly turn the light on and off. I'm no expert on light sensors, but it seems that some sensors could have this problem and you might not notice the flickering if the sensor had a very quick response time. You would just notice the dim incandescent bulb which is receiving 50% power.
I'm just doing some educated guessing. As an extreme example, a 60 cycle per second flicker would be similar to the action of a diode placed in series with an incandescent bulb. The diode will reduce the power to the bulb by 50% and you'll never notice the flicker but you will notice the dim bulb. I'm not certain of the actual lumen output of the bulb because it is dependent upon both current flow and filament temperature. But the reduction in light output with a diode is at least 50%; probably much more. (A 100 watt bulb puts out more light than two 50 watt bulbs since the two 50's are operating with cooler filaments).
2) A properly functioning screw-in photo sensor should not dim the attached bulb. You may want to test the sensor you own by covering the sensor with a bit of electrical tape to see if you get full brightness.
3) Try another screw-in sensor or two. Open the packages carefully so that you can return the sensors if they don't work. I would guess that some sensors are better designed than others. Not all engineers are created equal. :)
4) If you are really lazy and looking for a quick solution, you could always go for a higher wattage bulb in the hope that when dimmed it will give you the light output you want. I don't seriously recommend such half-assed solutions and I'd never try it without using a clamp on meter to determine effective current flow through the outlet. Even then you run the risk that the light may sometimes receive full voltage and full current, which could compromise the life of the outlet.
Good luck, Gideon
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John R. Bartos wrote I would like to find the best solution for having my porch lights turn on automatically at dark and off at dawn. I have two porch lights controlled by one switch. I tried one of those screw in sensors and it diminished the brightness in the bulb to such an extent as to be worthless.
Any recommendations?
John