I had a friend visit the other day that works in the lighting section of the film business. He was telling be about ‘lite ribbon’ and how it has perfect colors and is dimmable without any flicker. In the past while working with arduino and various led projects there was always a flicker that bothered me. The flicker happened while dimming and transitioning between colors especially deep red.
The way I understand it is leds can be dimmable through analog avoiding PWM (flicker) but also loose color quality while doing this. How do you think these led products at movie quality are made? Are they just using high quality leds that they dim via analog controls or are they still using PWM? Maybe usinging a micro controller pushing PWM signals that get translated to a voltage with capacitors.
Anyways. I thought this was interesting and thought others here would find it to be as well.
I used to be in the TV business and we would “GenLock” all the cameras and recorders together. That was the only way to ensure that each piece of equipment would start the next frame at the exact same time. If they weren’t all synced together, you would get a GIANT flicker every time you would switch to that video source.
I assume they found a way to sync the timing of the LED’s to the camera’s.
Hope this helps.
That’s cool that you guys would sync it all together to get the shot right! I imagine that was not an easy task.
I don’t think that is the method these new LED systems are using. My Dad happens to be in film to and I just got off the phone with him about the subject. He says that there are a good amount of LED light companies out right now in the industry asides from ‘lite ribbon’. Apparently none of them require adjusting the shutter speed to match up with the light. Im thinking they must use some sort of circuit to smooth out the PWM to guarantee that a given shutter speed will perceive the light. I imagine this will also easily get rid of the perceivable flicker to the eye as well. Dad happens to be in film to and I just got off the phone with him about the subject. He says that there are a good amount of LED light companies out right now in the industry asides from ‘lite ribbon’. Apparently none of them require adjusting the shutter speed to match up with the light. Im thinking they must use some sort of circuit to smooth out the PWM to guarantee that a given shutter speed will perceive the light. I imagine this will also easily get rid of the perceivable flicker to the eye as well.