How to Deflicker Time-Lapses?

Lassen Volcanic National Park Milky Way | Sony Alpha a7 II + 16-35mm f/2.8 GM @ 16mm, f/2.8, ISO 4000, 15 sec

Before I start my tutorial, here is a little story. Recently, I was just looking over my portfolio of photos that I have taken in the past couple years. And I am still in awe of the photos that I have taken. I have taken almost all of them on some sort of family trip, and they all bring back distinct memories of those adventures we shared together. Now, it has been about a year since I created this website which allowed me to share longer form stories that I could not share through a normal social media post. Looking back, it has allowed me to document these memories from my adventures and relive these moments. And through my stories and photos, I hope that maybe you got some entertainment value from it. So here is to another year of blogging!

Now that I am done with school and have more free time on my hands, I also hope to provide educational value through these blog posts too. Since I have just finished up a couple films this year featuring a handful of time-lapses, I thought I start out by sharing some tips about the best software to edit time-lapses and how to use them to deflicker, fix the staccato effect, remove birds/airplanes, and for time remapping.

To start off, I edit my raw photos with Adobe Lightroom Classic CC. Aside from being a long time user of all of Adobe’s products, Lightroom Classic is really the best way to edit time-lapses because of its ability to save metadata sidecar files (.xmp) so that it can be read by other applications. This is important because a common problem in time-lapse photography is flicker, and Lightroom Classic alone cannot deflicker your sequence. Flicker occurs because the changing light causes slight variations in the exposure of your image.

In order to process my time-lapses quickly, I use LRTimelapse which makes it easy to set key frames, create smooth transitions, deflicker your time-lapses, and much more. Additionally, LRTimelapse can natively read and write to the metadata used by Lightroom Classic so that you can apply the smooth transitions and deflickering settings directly to your raw photos. If you want to learn how to use LRTimelapse with Lightroom Classic, I already wrote a tutorial for the Purdue Photography Club which you can read here.

GBDeflicker with Masking Example in Adobe After Effects. Make sure to feather your mask too

Another tool that I like to use to deflicker a time-lapse is the GBDeflicker plugin for After Effects. The cool thing about this plugin is that you can set an area from which you want it to analyze the sequence. Then, you could deflicker both your sky and foreground separately, layer them on top of each other, and mask them together. Additionally, like any other layer, you can animate your mask if you have a motion controlled time-lapse sequence.

Another problem in time-lapses is the staccato effect. In traditional filmmaking, you want your exposure time to be half of your frame rate. Or in other words if your frame rate is 30fps (you are taking a new frame every 1/30 seconds), then your shutter speed should be 1/60 seconds. This is called the 180-degree shutter rule. In time-lapse photography, you may have a 1 second exposure, but with a 7 second interval for slow moving clouds at sunset (if you did not use an ND filter). That means that you will have 6 seconds of gap time which could create some choppiness in your final time-lapse video. To smooth out this choppiness in the moving clouds, water, people, cars, etc., you can use the echo effect in After Effects. First, change the echo operator to “Composite in Back”. Then, change the number of echoes to the number of frames after the current one you want it to be blended with. The decay is the percentage the frame’s opacity decreases by. So, .50 means that the current frame will be 50% opacity one frame from now and 25% opacity the next and so on (assuming you starting intensity is 1).

What if you have birds or airplanes in your time-lapse? You can use the use the echo effect with the “Maximum” blending operator as I show in my YouTube tutorial video above. This is made possible because the maximum value of the blended frames will be the brighter sky when compared to the darker bird/airplane.

However, if you have a milky way time-lapse (or in a situation where it is hard to distinguish the brightness value of the bird/airplane from the sky), you will probably need to remove these from each individual frame manually in Photoshop. To do this, open your first photo and then put the subsequent photo on the layer above it. Align the two photos using the transform tool (CTRL+T or CMD+T). To make small adjustments using the transform tool, use the arrow keys. Also, if you change the blend mode to “Difference”, then it can be easier to visually align them. Once your two photos are aligned, then simply create a black layer mask on the top photo and paint away the bird/plane with a white brush. The painful part is doing this on every single photo in your time-lapse to remove all the birds/planes.

Optical Flow vs Frame Blending. You can access it by right clicking on the clip and going to Time Interpolation or Speed/Duration…

Now you are editing your time-lapses together in Premiere Pro, but your time-lapse is not long enough. Then, you can stretch your clip using the selection tool (or speed and duration panel). And then, you can change the time interpolation to optical flow to artificially create frames to stretch the length of your clip. Personally, I would not stretch your clip past twice its original length (50% speed) because there are only so many artificial frames that Premiere Pro can create before it becomes noticeable. Also, make sure to render out clips with optical flow in your timeline (green color bar) or else you will not see the result of the change.

If you want to speed up your time-lapse clip, but now you are noticing some choppiness. Then, you will want to change your clip’s time interpolation to frame blending. This blends the surrounding frames together to smooth out the choppiness that comes from skipping frames in your original video sequence. Once again, make sure to render those clips in your timeline so you can preview the change.

Finally, if you are not changing the speed of your video clip, then keep the time interpolation on frame sampling. Hope you enjoyed this little tutorial! And let me know your thoughts or what you would like me to write about next! If you would like to see my last time-lapse film, check out my YouTube video or see the behind the scenes blog post.