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Star Trail Timelapse Video Tutorial

Create a timelapse video that simulates a long-exposure effect using a set of ordinary pictures.  See the example below

This tutorial assumes that you already have a set of 50+ pictures that are edited the way you want.

I will use Adobe After Effects to create the video, and Adobe Media Encoder to export to a .mp4 file. 


When taking the pictures for a timelapse, it might be helpful to use the following formula to estimate how long your shutter speed should be. (Assuming a 30fps final video)

desiredLength [seconds] = Final length you want your timelapse to be

shootingMinutes [minutes] = How long you're going to leave your camera set up to take pictures

shutterSpeed = (shootingMinutes*60)/(desiredLength*30)

which simplifies to

shutterSpeed = shootingMinutes*2/desiredLength

If you're planning on shooting for 2 hours (120 minutes), and you want a 7 second timelapse out of it, the calculation gives us

120*2/7 = 34.2 seconds

Then you would set your intervalometer for 34 or 35 second exposures.  

For more recommended camera and editing settings for star trail pictures, read the "Star Trail Picture Tutorial


1. Open Adobe After Effects, start a new project.

2. Click File > Import > File...

New Project
Import Pictures
Step 1  import pitures to After Effects

3. Select all of your photos, click Import

Step 3 - Import pictures into After Effects

Don't select "ImporterJPEG Sequence".  It imports the pictures in a way that this tutorial does not cover. 

4. Select all photos on the left, and drag them to the bottom area

New Composition
Step 4. Add pitures to coposition in AE
Step 4. Add pitures to coposition in AE

Alternately, right click the selection of photos and select "New composition from selection".  If the box shown on the right pops up, leave the settings as they are and click OK.  

5. Click Composition > Composition Settings...

6. Change the Duration to something longer than you need

Composition Settings
Stp 6. Change Duration in After Effects
Stp 6. Change Duration in After Effects

7. With all layers selected, drag their duration as short as possible (1 frame)

Layer Duration
Step 7. Make eac picture 1 frame long

Each picture should be 1 frame in length.  They should currently still be completely overlapped.  

Stp 7. Make each picture 1 frame long

8. With all pictures selected, right click any duration bar and select

Keyframe Assistant > Sequence Layers

Sequence Layers
Stp 8. Keyframe Assistant Sequnce Layers AE
Stp 8. Keyframe Assistant Sequnce Layers AE

The settings should be fine as default.  

9. With all pictures selected, change the layer mode from Normal to Lighten

Layer mode: Lighten
Step 9. Layer mode to Lighten in After Effects

10. With all pictures selected, drag the duration of a picture so that it is longer than the video length

Increase Frame Duration
10. Make picture length full video
7. Make picture length full video

Where the duration of the picture ends is where it will stop appearing as a part of the trail.  So if you make each picture duration to be 30 frames long (1 second), then the star trail shown in the video will be of the previous 30 pictures.  Play around with the length to see what it changes.  I recommend moving the time cursor to where the last frame begins, and then scrolling back to the first frame and dragging its length to/beyond the time cursor.  

11. Export the video by selecting File > Export > Add to Adobe Media Encoder Queue

Export Video

I hope these steps are clear enough.  If you'd rather watch a video walkthrough, watch the below video that I made. 


Video Tutorial (YouTube)
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