I am planning to shoot a timelapse sequence with a slider moving across a creek with many plants growing along side of it and with plants on rocks in the creek. Even with an ND filter and long exposures, there is too much movement in the plants (due to wind) and in the water between each frame. The whole scene jiggles and wiggles just too much. If I was to shoot from a tripod, then the solution is simple: add motion blur and the sequence gets smooth. But I can't add motion blur to a dolly shot, because that will blur everything, not just the movement in the plants and water. So my solution is to make 3 exposures, each time the slider stops for an intervall and in post add motion blur interpolating between the 3 pics taken at each intervall. No problem thus far but I am planning to shoot this while the sun is moving into the valley, illuminating the scene. So I need to use LRT to fix the exposure and HG steps.

But will that work? How can I tell LRT to treat groups of 3 pictures as 1 picture? That means the 3 pics I take at each intervall need the same exposure fixing.

One idea I had was this: split the sequence into 3 folders. Now I have three folders each with basically the same raw sequence, apply LRT changes to one folder, rename the all the files in the other folders with identical file names. copy/paste the xmp files and render each folder in LR seperately. Renaming is easy with the free Bulk Rename Utility pgm. But how do I seperate 3000 RAW files into 3 folders with 1000 files each - 1 folder with every 1,4,7,10th... pic, 1 folder with every 2,5,8,11th... pic, 1 folder with every 3,6,9,12th... pic and so on. There's no way I can do that by hand (life is too short). And I can't write a script to select those files, so I could extraxt them from the original folder after selecting them, because I don't know a thing about scripting or code.

Does anybody have an idea? Can I use this workflow in LRT4 or do I need to seperate the files into seperate folders? How do I do that? Can anybody supply a script with instructions? Thanks in advance!

It's a bit like HDR, I see 2 options:
1) Combine the 3 images first, do the deflicker later on the combined images in LRT
2) Separate the images (every 3rd) into 3 folders, you can use the "Edit / Select every nth" feature in LRTimelapse and then right click on an image, "new folder from selection". No need to rename the images then. Apply the deflicker to each of the 3 folders, then just move them back into the main folder (use LRT for moving, this will preserve the previews).

Great! Thanks Gunther! I didn't know LRT had the "Edit / Select every nth" feature. Way to be!