Hello - I'm sure there must be a way to do this, but I can't seem to figure it out. I have a timelapse shot of a full moon rise. Given the wide discrepancy between the brightness of the moon and the overall landscape I've tried to kinda split the difference in exposure settings. This gives me a moon which is too bright and pretty much completely washed out. I've been trying to add a mask over the moon itself to bring the exposure down so I retain detail in the moon surface. Mostly this works well. My problem is I have placed my first mask over the moon just as it peaks over the horizon and then it tracks nicely between keyframes from then on. The problem is there appears to be a default location of the mask which then transitions down from somewhere in the middle of the frame and morphs into the mask that I've placed on the first frame of the moon. What I'd like is for the mask to be "off" prior to that first frame of moon and then transition and track the moon as it passes over the sky. How can I have the mask "off" and then turn "on" at the correct spot on the first frame of the moon?

You'd need to animate the mask from the beginning (very first keyframe). Just set the position, you could even set if outside the frame. As long as you don't need the maks, leave the tool settings at default. Then start bringing them in, as you need them.
I've explained this in my expert tips tutorial #2 (I'm showing this with the older gradients there, but the same applies to the masks): https://lrtimelapse.com/tutorial/expert

thanks Gunther - I got it as well later that night. Just put a keyframe right before the frame that I wanted it to appear in, set all the settings to zero and everything seems to work nicely now. Just couldn't seem to get my head around it. Should be a nice shot when its done!! Thanks for responding and thanks for creating LRTimelapse. Don't know where I'd be without it.

cheers.