Dark lines in 45 degree shutter angle

Hello,

At 45 degree shutter angle I am getting dark lines. Anyone know why?
When I look at the footage it shows the image with very top bright then dark shadow line them bright again and the dark again. I hope I am making sense

It could be the camera's shutter interacting with a PWM-driven lamp, like some LED lighting or fluorescent lighting. Simply put, the lights turn on and off very quickly and the camera, when set to a faster shutter speed catches part of the cycle.

The BMCC uses a rolling shutter and as a result different parts of the frame are exposed at different points in time. Under non-tungsten lighting part of the frame is often exposed during the dark portion of the light's cycle and another part of the same frame could be exposed during the lighter part of the light's cycle.

I hope that helps.

Excellent explanation! (I'd given the same, yet in many more and much more confusing words...)

Thanks man. I tried to make the explanation as simple as possible without losing a bit of the subtlety behind why it occurs. A lot of issues can be rectified if one has an understanding of shutter/frequency interaction.