I have taken some Drone video shots that were shot in 4k 60fps and edited them in Premiere Pro CC. When compared to my source/original video, the end product when exported has this steady and timely pulsing change in brightness. It is continuous throughout the video at the rate of about a pulse every half second. At first I thought it might have been the drone but the original video clips do not have this. Its only after edited in Premiere Pro. Any idea what this might be? And thank you for any advice/help you can share.