I have a timelapse composed of 180 night photos, all captured using D800 and 14mm lens with 25 second exposures at F/2.8. I am getting a random darkening spike about half way through the timelapse. I checked my RAW images and there is no darkening, any thoughts as to why my sky is darkening like this? I used 2 keyframes one at the start and one at the end, and tried using more. All to no avail. Attached is a screenshot showing the sky darkening on the previews curve.

Thanks,

Matt

This could have multiple reasons, probably something Lightroom is introducing due to some tools being context sensitive.
I'd not worry too much, just use the visual deflicker, drag the smoothness to the right until you get the desired curve/line and apply it. You can use refine too, if it's not sufficient.
Maybe it could be good to use a larger reference area too, to avoid having too much influence by some lense vignetting.

Hi Gunther,

Thank you for the assistance. I followed your advice and applied visual deflicker, but I am still searching for a root cause issue with why Lightroom is doing this? The video still has that flicker, just not as pronounced. I have had other timelapses suffer from this. Is there a certain setting I shouldn't be using in LR? From your video, I recall that all the settings are able to be used in LRT 4. Just trying to see what is causing this as it does not make sense to me since the RAW files show no flicker issues.

Attached is a pic of my main keyframe settings.

Thank you very much!

Matt

Hi Matt,
of course, technically you can use (nearly) all Lightroom tools. Check out this faq post:
http://forum.lrtimelapse.com/Thread-what...htroom-acr
But some tools are context sensitive, so they might introduce effects like that one that you are seing.
When you notice something like this, mostly it helps to bring down some of those sliders like clarity and dehaze.

Just a side note on your editing: it's rather unusual that you brought all the 4 dynamics sliders (highlights, shadows, whites and blacks) to right. This is kind of counter productive. I recommend to use those sliders in form of a "D" (I call it the dynamics-D): highlights to the left, shadows to the right, whites to the right (if needed), blacks to the left. Work from top to bottom and use Exposure to do the general brightness adjustment. With that technique, you mostly don't need tone curve at all.

The way you did it is using the 4 D-Sliders to bring up brightness (instead of exposure) and then increase contrast with the tonecurve. Might work, but it's rather strange.

BTW: This advice is a general one that I teach in my Lightroom classes, time lapse specific.