Sunset time lapse: Progressively increase exposure for a range of pictures?

[rafaelmesquita]

Is there a way to program Lightroom to increase exposure by a certain amount of units at every X number of pictures?

I am working on a ~500 pictures time-lapse of the sunset. During the shoot, after every 100~150 pictures or so, I would reduce my shutter speed. As it was a sunset, I needed to do that because light diminished with the passing of time. In total, I reduced shutter speed 3 times for the whole sequence.

The problem is that because of that the image sequence does not playback smoothly: at every 100 pictures there is a sudden boost in the brightness. This is because all pictures 1 to 100 were taken at, say, 1.8s shutter speed, but pic101 was taken at 2s shutter speed. Hence the sudden boost.

I figured this could be solved if there was a way to instruct Lightroom to change a specific attribute by a certain amount at every picture. For example, "at every 01 picture, increase exposure by +0,01 for the first 100 pictures". Thus, pic1 would get +0,01, pic2 +0,02, pic3 +0,03... pic100 +1,00. Like that, the whole 100-picture sequence would have its exposure gradually increased, so that, by the end of it, it would be bright enough so as to smoothly match pic101 and its ensuing sequence.

This can of course be done manually, increasing the exposure of all pictures one by one. But I was wondering if anyone knew how to do it automatically.

Thanks in advance!

[johnrellis]

If no one else has a better suggestion, here are a couple of ways you might try for getting all of the pics to have about the same brightness (which may not be exactly what you want):

1. You could try the Settings > Match Total Exposures command in Develop, but it's not likely going to help, since it's going to adjust all the photos to have the same effective exposure value (ISO, shutter, aperture, exposure slider), and you'll likely still see the stair steps in birghtness.  Match Total Exposures looks at the camera settings and slider only, not the actual pixels of the pics.

2. You could use LR's auto-tone to automatically adjust just the exposure of each pic based on the actual pixels, which should adjust the pics to have about the same brightness.  But it takes a little bit of a song and dance routine:

a. Define a develop preset "Zero Basic Tone Except" that sets all the Basic Tone sliders to 0 except exposure:

b. In grid view select all the pics and apply Auto Tone using the Quick Develop panel:

c. Do Library > Build Standard-Sized Previews to work around a nasty LR bug.

d. Apply the "Zero Basic Tone Except" preset using the Saved Preset dropdown to clear all except the Exposure slider:

LR's auto exposure can make pics a stop or so too bright.  So you could use Quick Develop's Exposure buttons to make the same relative increase or decrease in Exposure to all the pics at the same time:

I don't know if this will give you satisfactory results, but I think it will eliminate the stair-stepped brightness.  If you try it, let us know how it turns out!

[johnrellis · Accepted solution]

On second thought, Match Total Exposures might work out very well and eliminate the stair-steps in brightness.  Give it a try!

[rafaelmesquita]

Thanks all for the feedback!!

Match total exposure did the trick just fine!

There was a small glitch on the way: my lens is a manual focus Rokinon which was not identified by LR, so if I tried to run Match Total Exposure with the original pictures an error would pop up saying no pictures were selected. Turns out that there has to be metadata on aperture, f-stop and so forth for Match Total Exposure to work, and since there was no info on my lenses, the command would not work. Therefore, I had to download the LensTagger plugin so that it would input the metadata concerning my lens for the batch of photos. After that, the Match Total Exposure did the job.

[johnrellis]

Good.   And thanks for the pointer to LensTagger -- I hadn't seen that plugin before. 

[bhousto90]

You may also want to try Jeffrey Friedl's “Timelapse Support” Lightroom Plugin that says it will allow you to 'fade in/out' develop adjustment amounts:  Jeffrey Friedl's Blog » Jeffrey’s “Timelapse Support” Lightroom Plugin

I have not used it myself but came across it when checking out something else on his site.

-BH

[John Waller]

I found this interesting for 99 Euros.

LRTimelapse | Home

[johnrellis]

Good suggestion, I forgot about LRTimelapse.

[John Waller]

Have you any experience using it John?

It's new to me. I might take it for a spin.

[johnrellis]

No experience with it -- I've just seen it mentioned on these forums a fair number of times.

[Conrad C]

I use LRTimelapse. I think it's very clever and well-executed. And it's perfect for the original problem in this thread, because it can ramp most of the sliders in Lightroom.

The basic idea behind LRTimelapse is the use of keyframes and XMP metadata. You tell it how many keyframes you want between the start and end of the time lapse; if you only need two different Exposure values at the beginning and end, that's two keyframes, but if you wanted another change in between you'd add three. LRTimelapse then uses metadata to mark the keyframes in XMP sidecar files, then you read the metadata changes into Lightroom and use the Develop module to edit the parameters of just those images. It's no problem to apply an idea such as "I'd like to gradually shift the color temperature across this time lapse;" just set the Temperature values of the start and end keyframe images in Develop.

You save the metadata back into the frames and have LRTimelapse read the updated metadata, and it interpolates the intermediate values for all of the images between the keyframes, and writes its edits into the metadata for all of the images. LRTimelapse is very good at compensating for things like if you changed the shutter speed three times during the time lapse to avoid overexposing a 3-hour sunrise. LRTimelapse can also apply adjustable flicker removal, which can be very important to smooth out the exposures from some cameras and lenses. The whole program is sort of a super Match Total Exposures.

LRTimelapse then writes out all those changes into the XMP sidecar files for the last time, you have Lightroom read the final Develop values back in for the original raw files, and then you use a special LRTimelapse Export preset to render all those frames to a video file.

Obviously, for success with LRTimelapse, it's important to be comfortable with how the Save Metadata To File and Read Metadata From File commands work in Lightroom. And follow the workflow tutorials on the LRTimelapse website very closely.

It's a lot of money unless you're going to do a bunch of time lapses, but if you use it, it does a very good job.

[John Waller]

Thanks Conrad. Great overview.

[rafaelmesquita]

By the way,

end result is here!

I used the Match Total Exposure solution in the opening sequence of this clip. Thanks again for the support everyone!!

[johnrellis]

Very neat!

[TimmyBaker]

Awsome clip! Saw your question about the time lapse exposures jumping for your intro piece you have here, and had the same struggle searching around for an answer. Thanks for the tips, I have one now that I want to run the process on and see the end results. Was also looking at LRTime Lapse, but already pay for CC so prefer a solution within that stack. Have a rad day!