Hi.
I use a lot lrtimelapse with 2 pass.
First one putting all my holygrail keyframe, and correcting exposure and basic tweaking of photos. Then when all my exposure are matched. I go back to Lrtimelapse, delete all key frame and only put some keyframe where I need, basicaly, when light change. I go back to lightroom and can tweak White balance and other setting and have a nice transition over time without having to deal with 10 or 20 holygrall key frame.
I have nice result with that method, but i can' touch the exposure in the 2nd pass because of the exposure change at holygrail frame.

My thought is to save the exposure collum after the 1st pass, tweak exposure in LightRoom on a few keyframe. When you reload in LRtimelapse, take the difference between the first exposure pass and the second at keyframes, smooth this new value with transition and adding them back to the first exposure.
That way we can correct the exposure change in first pass and adding smooth exposure transition with the second

I hope I've been clean enough.

That sounds rather complicated. What you are doing is not a real two-pass-approach. In the real two-pass-approach you would export JPGs after the first pass and make further adjustments after (that's what I explained in the 2-pass-deflicker tutorial).

I don't understand why you would want to change exposure after doing the holy grail maching, I suggest doing this right in the "first pass" when working from left to right, anything else would get way too complicated for most of the users.

Hi,

The issue Shuma is addressing is actually a very valid one and one of my main issues with LRTimelapse. Let me try to explain why:

If we for simplicity divide exposure changes into two separate categories, local and global.

Global changes are changes that stretches through the entire timelapse sequence. The sequence maybe gets darker over time, or brighter, to compensate for light decay.

Local changes are changes between consecutive frames to compensate for camera exposure changes when shooting as light condition changes. These changes are the holy grail keyframes.

The problem is that LRTimelapse mixes global and local changes into one keyframe making individual changes to local and global settings impossible. If I have a timelapse shot using the holy grail method and I have maybe 30 keyframes that each need to be matched very carefully. When this is done I may realize that the overall brightness of the sequence need to go down at the end. But this is very difficult to adjust since I can no longer do global changes to the sequence because of the holy grail keyframes. The only way is to once again go through all keyframes one more time and try to make a smooth curve throughout the sequence, little by little decreasing the exposure for each keyframe, and also rematching the 2 and 3 star frames. I find this nearly impossible to do in practice since often the keyframes are not evenly spaced.

What I suggest is some way to keep the local and global changes separated. Maybe a new type of keyframe that also affect the values of the other keyframes. If I wanted to make the entire sequence darker at the end, I would put one of these keyframes at the first frame and one at the last frame and decrease the exposure of the last frame. When I make an auto transition, this new keyframe also affects the values of the other keyframes in between in a linear way.

Or maybe having different sets of exposure curves, one for global exposure and one for local holy grail keyframes and then being able to merge these curves.

Maybe this is not possible to do the way LRTimelapse is implemented, but I thought it would be a great feature.

/jonas

Your points are valid. No promises but I'm going to think them over. I have a lot of HG-editing to do when I come back from Africa so I will have a lot of material to try things out with. :-)