Testing the LED refresh rate speeds. You can see the “wavy” banding of light in this video, and that’s because of the refresh rate of the lighting system. You can see that new LED lighting systems are not based on the 60 Hz rate anymore, and this system is based on 80 Hz refresh rate. To counter this, the shutter speed must be at 1/80 sec, or multiples like 1/160 sec. Normal lighting, like incandescent or fluorescent, are based on the electrical rate. In the US, that’s normally 60 Hz, in the EU it’s 50 Hz. What does that mean for shooting HDSLR video? Well, I shot this example in 24P and there are no problems. However in different situations it could be a problem. Always test the lighting to make sure that you have the right shutter speed (as well as exposure).
This example was shot at the new Hard Rock Cafe in Waikiki, Hawaii. The stage was dark, except for the LED spotlights. Dark stages and venues are a common theme for any musical event. I’m still at a loss as to why the venues continue to have the stage dark, I mean you have to be able to see the bands playing, right? Below is an example of how LED spotlights can wreak havoc on filming. The ones at Hard Rock didn’t have a conventional “dimmer” switch, so instead of dimming the brightness, it actually shuts off certain LEDs. This meant that all kinds of strange banding occurs, as can be seen at time 0:36 of the video.
Working around these limitations is a challenge that we as filmmakers must overcome in the future.