Exposure Shift in Timelapse After Syncing Settings in Lightroom

[vvivek4ever]

Hi everyone,

I’ve been using Lightroom for over 10 years and specialize in timelapse photography. I’ve never faced this issue before, so I’m hoping someone can help.

I have a custom preset that includes basic settings, curves, color grading, and calibration settings. My usual workflow is to apply this preset to one image, make any necessary corrections, and then sync all settings across the entire sequence of photos. In the past, this method worked flawlessly, with no noticeable differences between images upon export.

However, for my last two timelapses, I’ve noticed a shift in exposure between many consecutive images. Initially, I thought this was due to changing light conditions that the camera couldn’t handle. But today, I’m certain it’s an issue with Lightroom’s sync function. I have two images with very similar camera settings and Lightroom edits, yet there’s a noticeable difference in exposure. Apart from changing colors in two far-away buildings, the camera settings and Lightroom edits are the same.

For a recent timelapse with 330 pictures, at least 35 images have this issue, resulting in flickering in the exported video. This is really frustrating.

I’ve attached screenshots of image 1 and image 2 along with their edited versions, along with the system info, for reference.

Any insights or solutions would be greatly appreciated. Thanks in advance!

[Moved from ‘Bugs’ to ‘Discussions’ by moderator, according to forum rules.]

[johnrellis]

"DirectX: NVIDIA GeForce GTX 1650 (31.0.15.4609)"

That driver is about seven months old. It's probably not causing your issue, but it's always good LR hygiene to be on the latest driver. Go to Nvidia.com and install the latest Studio driver.

[vvivek4ever]

Thank you for the suggestion. I'll definitely update to the latest Studio driver. It's good to rule out any potential contributing factors. I'll update the driver and see if it makes any difference.

[johnrellis]

I think the only effective way to narrow down the issue is to share the original two raws and the develop settings.  Select the first raw and do Metadata > Save Metadata To File. Then upload both raws and the .xmp sidecar for the first one (which contains the Develop settings) to Dropbox, Google Drive, or similar and include the sharing link here.

[vvivek4ever]

Thank you for the suggestion. 

I wanted to mention that Richard's suggestion made a lot of sense. I retained all settings but set shadows and highlights to zero, and the images seem to match now. I am attaching the images for your reference

[vvivek4ever]

John, would you want RAW images and xmp to review?

[johnrellis]

It seems you're satisfied with the cause of the issue, so no need for further analysis I think.

[vvivek4ever]

While bringing highlights and shadows to 0 has helped with the exposure flickering, it significantly impacts the contrast and color scheme I usually achieve. How can I effectively adjust highlights and shadows on top of a point curve that already has adjustments? Is there a best practice or workflow that allows me to maintain the desired color and contrast while minimizing flickering?

Any advice on this would be greatly appreciated.

[richardplondon]

Looking at the edited samples I do wonder if this could be arising from the nature and strength of adjustments used. Some Basic adjustments - shadows / highlights and clarity in particular - are more image-contrast-adaptive: meaning that for each image they are applied to, even when the slider is moved to the same value, a fresh assessment will be made for each image on how it should apply (a pixel of the identical starting value may receive a different adjustment within the two images, depending on what other tonalities it accidentally occurs in proximity to). The reality is that physical shutters are not perfectly repeatable from one operation to the next, so the absolute camera exposure may vary slightly even if everything is locked down on Manual. Also shot noise and to a lesser degree read noise is inherently variable shot to shot.

So very heavy use of a few strongly image-adaptive adjustments will tend to magnify any accidental variations between the original shots. More moderate use of these adjustments and the strategic combination of different adjustments will tend to do so much less, perhaps below the threshold of noticeability, all else being equal.

In my experience it's far better to (for example) combine a moderate general Contrast slider adjustment with moderate Shadows / Highlight adjustments, rather than (for example) trying to achieve everything just from setting extreme values for the Shadows / Highlights sliders.

Also, Tone Curve is not image-adaptive at all AFAIK, so this can act more as a neutral and constant tonal 'overlay'. Note highlights recovery for example, must be addressed properly in Basic panel adjustments: Tone Curve cannot optimise such things absolutely. It can only relatively darken or lighten whatever the Basic adjustments are producing.

[vvivek4ever]

Thank you for your detailed response. I think you're spot on with your analysis.

After reading your explanation, I decided to test your theory. I retained all the edit settings except for highlights and shadows, bringing both of these to 0. Surprisingly, the image looked almost the same as before.

Given this, I'm now looking for advice on how to best sync these settings across all images without introducing variability. Should I avoid using heavy adjustments for highlights and shadows altogether, or is there a better approach to achieve consistency?

Any tips on the strategic combination of different adjustments to maintain uniformity across the timelapse sequence would be greatly appreciated.

Thanks again for your help!

[vvivek4ever]

Attached images for your reference after bringing Shadows and Highlights down to 0.

[johnrellis]

As Richard mentioned, Tone Curve adjustments are not image-adaptive, so you should get more consistent effects with it.

[richardplondon]

I think Highlights and Shadows are fine tto use, and to sync, when kept to moderate values. The same for Clarity and Texture. Personally I would begin from Exposure and Contrast to suit the overall picture that you want, then set Blacks and Whites for the specific way you want the very darkest and very brightest areas to appear. Only in response to all that, would I then apply some tweaks of Shadows and Highlights which could probably then be relatively mild - therefore, non-problematic. Sometimes further tweaking Whites and Blacks to put back any "life" that may have been lost in the course of lowering general picture contrast. Or applying positive Clarity, though this would need an extremely light touch with scenes such as this.

That coloured floodlighting on the buildings with its very monochromatic, almost blown-out appearance is going to be especially difficult to keep within bounds. It may be worth experimenting with some different camera profiles to see which one deals with that aspect the most believably. Some profiles do very unnatural things at the extremes of certain hues.

If you'd like to share two example Raw files (uploaded to somewhere else, and the link posted here - you cannot directly upload a Raw to this forum I believe) perhaps any interested people may like to share how they might have handled this.

[johnrellis]

"I think Highlights and Shadows are fine to use, and to sync, when kept to moderate values."

Unfortunately, what constitutes "moderate" varies greatly between photos.  

Here's an example where Highlights = 30 / Shadows = 21 results in much different output on similar images with very similar histograms:

https://community.adobe.com/t5/lightroom-classic-discussions/fehler-nach-kopierten-entwicklungseinst...

I've seen examples where Highlights and Shadows = 10 an cause LUTs exported from my Export LUT plugin to produce significantly different results than how the settings appear in LR.  (The plugin applies the LR settings to a test-pattern image to generate the LUT, and the image-adaptive nature of the Highlights and Shadows algorithm mean they can have much different effects on a photo than on the test pattern.) When Export LUT users switch to the Tone Curve, their exported LUTs are more faithful to LR's settings, since Tone Curve isn't image-adaptive.

[richardplondon]

It might have been better to say "slight" rather than "moderate".

Some people may think 50% between zero and max is 'moderate'. Or, 90%.

But to draw an analogy: for what percentage of the time does a typical car use any of the right-hand side of its speedometer dial? If we stand on the car's accelerator pedal and attempt the dial's very highest numbers, we can expect some unwanted consequences - without achieving the hoped-for result! 

[Conrad_C]

I was thinking of answering with a reply similar to richardplondon’s, and the only reason I didn’t post that earlier is because you’ve done a lot of time lapse photography, so I thought maybe you might already know about the issues with image-adaptive adjustments. But now that your testing seems to confirm that it does have to do with adaptive adjustments such as Shadows/Highlights, I agree that a solution is to do as much tone adjustment as possible using the Tone Curve, and if that isn’t enough, then add Shadows/Highlights and other Basic panel adjustments, but only as little as needed.

If this is the first time you’ve come across this issue, watching the video below is highly recommended, where the developer of LRTimelapse software goes into great detail about how to avoid exposure flickering induced by Lightroom Classic adaptive adjustments. The last part of the video, starting about 13 minutes in, is a revealing analysis of exactly which adjustments cause the most and least flickering when synced across many images. (From his article Stop Lightroom from adding Contrast Flicker to your Timelapses)

Also, note in the video that he demonstrates how some unwanted shifts may be made worse depending on whether a camera or Adobe raw profile is applied! This was new info to me.

[vvivek4ever]

Thank you for your insightful reply. Although I've been doing timelapse photography for a while, there's always something new to learn. This issue with adaptive adjustments and exposure flickering is entirely new to me, as I've never faced it before.

I typically edit with a combination of tone curve adjustments along with basic adjustments. However, not using highlights and shadows from the Basic panel is actually disrupting my workflow, and I'm unable to achieve the usual color and contrast I typically get with the combination.

I watched the LRTimelapse video you recommended and now understand how some adjustments can cause contrast flickering. I purchased LRTimelapse and am currently exploring different videos. It’s a nice tool.

Do you have any additional tips on how I can balance using both tone curve adjustments and minimal basic adjustments to maintain the color and contrast I'm aiming for?

Thanks again for your help!