Hi there!

Needless to say, masks work wonderfully and since I learnt how to use them my timelapses have improved a lot. But using Lightroom and its own way to deal with masks I had this idea.

I use Lightroom mainly to edit landscape photos. While editing , I find the feature "Detect sky" very useful: first I create a mask for the sky, then duplicate and invert the duplicated one, so I get another mask for the floor.

It would be great if we could use this kind of "custom masks" to be applied to our timelapses, given the fact that there are scenarios in which certain elements of the landscape (rocks, trees, etc.) get into the sky, so the regular linear gradient we create for the sky is also applied to these elements.

Hope it makes sense! I don't know if this is doable or even possible, and probably I'm not the first who requests this feature. Anyway, here it goes!

Thanks in advance!

This post was last modified: 2022-04-01, 12:44 by Gunther.

I did't try it but you should e able to add those subject detect selectors to one of the predefined masks that LRTimelapse created.
Do that as the very first thing before starring to edit, on the very first keyframe. Then sync the mask you just edited to the whole sequence in Lightroom before starting to develop.
After that set the filter to "Keyframes only" and do the regular editing.
Please note that those selectors will be static, Lightroom doesn't recalculate it for every image.
The edits on the masks however will get animated as usually.
Let me know, if it works for you.

- I did't try it but you should e able to add those subject detect selectors to one of the predefined masks that LRTimelapse created.

With this do you mean adding completely new masks? Or intersecting LRTimelapse created masks with sky detection ones?

- Then sync the complete masks to the whole sequence in Lightroom before starting to develop.

I understand you mean synchronising masks only with Lightroom's "Sync" button... correct?

- Please note that those selectors will be static, Lightroom doesn't recalculate it for every image.

Sorry, I didn't get that, could you elaborate?

Thanks in advance!

1.) Any Mask in Lightroom can hold multiple selectors. Don't add new masks, just add the "landscape" selector to one of the masks that LRTimelapse created.

2. ) Use the Lightroom Sync tool to synchronize the Mask you just modified to all of the other images. If you get asked, use the replace option when syncing.

3.) If you select the sky on the first image and for example you do a pan with your camera you can't use this technique because the sky sector won't be recalculated for subsequent images, it will stay static. Even if you don't pan, a selection taken on the first image might not be really appropriate anymore at the last image. This is, why I don't officially recommend working with those masks for timelapse, mostly you get artifacts that are visible during the timelapse. But try it and see if you can get your desired results.

1.) Any Mask in Lightroom can hold multiple selectors. Don't add new masks, just add the "landscape" selector to one of the masks that LRTimelapse created.

I'm not a Lightroom expert but I'll investigate on how to add selectors to LRTimelapse's masks.

2. ) Use the Lightroom Sync tool to synchronize the Mask you just modified to all of the other images. If you get asked, use the replace option when syncing.

Ok, will do!

3.) If you select the sky on the first image and for example you do a pan with your camera you can't use this technique because the sky sector won't be recalculated for subsequent images, it will stay static. Even if you don't pan, a selection taken on the first image might not be really appropriate anymore at the last image. This is, why I don't officially recommend working with those masks for timelapse, mostly you get artifacts that are visible during the timelapse. But try it and see if you can get your desired results.

Makes perfect sense. I'm trying this on non-panned sequences. If it works OK on certain sequence, I'll be editing it with this custom masks, and if not I will use the default masks.

Thanks again!

Hi again! I want to share my findings with this approach:

Regarding masks and multiple selectors, I found the way to hold several selectors within the masks created by LRTimelapse. Lightroom's algorithm is somewhat "picky" regarding the detection of the sky, so manual adjustments have to be done in order to avoid artifacts later. But so far so good!

With respect to synchronising masks, the Lightroom Sync tool doesn't work as expected, since the "modded" masks can't be synced directly, they need to be recomputed by Lightroom's AI algorithm. So I used the regular script in the menu bar to apply the settings to every keyframe. Once the masks are copied over to every keyframe, the workflow is as usual.

I've tried this approach with a non-panned sequence and in my opinion, it is working pretty well! Here you have the sequence I used including all the editing:

https://youtu.be/o8v1FaWcMrc

Feedback and opinions on this are welcome! Thanks everyone and especially to Gunther.

Cheers from Spain!

Just adding that I played around with this tonight and found that for the most part the LRT masks can be modified using add/subtract sky and it tracks across frames. One thing to consider is the possibility of the tripod moving with wind, as any change to the position of the subtracted sky/landscape will not follow the movement of the tripod and will thus become visible.

I was surprised to find it consistently removed the landscape from an LRT mask that was following the Milky Way across the sky. Each frame had the sky modified but the landscape beneath it was clean. Impressive!

Thanks for your feedback!