Yup. Cameras with adjustable shutter speeds can often be set to compensate for this. It's similar to the reason why you couldn't easily film CRT TVs and computer displays without flicker. Many display technologies rely on high speed tricks like that to fool our eyes into seeing specific effects.LEDs are typically dimmed using PWM (pulse width modulation). They turn on/off many times per second, the more "off" time they have versus "on" time makes them appear dimmer. This happens faster than the eye can see, but cameras have a habit of snagging one of the "off cycles" making them appear to flicker.