I am finding that when we are filming guitar strings at a certain angle, you get terrible striping/lines/strobing across the strings, but nowhere else. It's not the same as 'string wobble', which you sometimes get with slo-mo etc. The settings of the camera are standard (24fps, shutter 50, f.stop 5.6, ISO 640, white balance 5500k). I've even taken the guitar outside and tried various settings and lenses, but I'm still getting this issue. Any ideas what it could be please? I have also tried it on our Canon 5D, but I get the same results. Can't see where to post an image as it might be easier to show it that way.