I have this single frame that I am compositing with another video. The single frame has bright light pushing through some curtains for a lightning effect into a darkened room. The scene I'm compositing it with is the same dimly lit room. Both shots from the same position.

I'm compositing with either lighten or screen and have shifted the light from the window to a colder/bluish light. I have velocity at 0 and just loop the lightning frame.

What I'd like to know is what is the simplest way of, for each frame, setting the level for the lightning. I could use keyframe I guess on each frame, but I thought there might be something easier? I need the equivalent effect of adjusting the track 'Level' control. There is a Levels effect, but I haven't used it. I'm more familiar with the Color Curves.

BTW, I shot some 'real' lightning through the same windows and measured the relative strength of the brightness of a couple strikes I liked. Now, I want to apply that pattern in this more controlled situation. If anyone is interested I'd be more than happy to share the lightning pattern.

Thanks for any suggestions.

Wayne