40 watt incandescent filaments compared

Different filament types compared.
Variac reduces line voltage to make filament contrast more visible to camera.
The 40 watt output is too bright for the camera.
Clear utility lights appear bright to the eye because all the light output comes from the relatively small filament. Compared to the standard frosted glass light where the light energy is spread over a much larger area.
Any 40 watt incandescent filament should produce approximately 400 lumens or 10 lumens per watt

Видео 40 watt incandescent filaments compared канала Brent Wegher