Rotolight and their ANOVA Bi-Colour EcoFlood LED floodlight, in a contest with other continuous light source LEDs, literally grabbed the spotlight in the flicker-free category.
Whereas other brands of LED lights displayed a noticeable flicker at 2000 fps and under, the Rotolight Anova was tested at every setting up to 7000 fps with no flicker whatsoever.
The secret? Apparently it has to do with the way conventional LED units utilize a process known as Pulse Width Modulation (PWM). In layman terms it means that so-called continuous lighting is not actually continuous, but is in fact continuously flashing at rates not visible to the human eye. Video and photographic cameras can see this high-speed PWM flashing and, when operating at higher frame rates and shorter exposure times, can render the video or photo useless.
The Rotolight difference? The Rotolight Anova does not utilize PWM at any brightness level but instead employs a special DC current control dimming system. It’s the only LED to do so, making it the only true professional LED lighting source that can be used with all higher speed cameras and shorter exposure times.