Library of Congress.
) Providing scholars and researchers with clean, bright focused light without disturbing sensitive, tired eyes, the lamp uses a patented halide-LED module that generates 7,000 lumens—more that 6X the light of a 75-watt incandescent bulb.An electronic ballast system constantly controls current to the halide filament (encased within a quartz arc tube) to ensure optimal spectral consistency and light output. When a lesser amount of light is desired, twin rocker switches turn on/off one or two LED arrays, which can be used with or without the halide bulb.