Timelapse Photography Using a DSLR, GoPro or Osmo Pocket

Source

I recently bought a DJI Osmo, which has a built in Interval Timer mode, which re-ignited my interest in making time lapse videos. The Osmo makes this very easy: you just set the timer interval, which determines the interval at which the Osmo takes a JPEG and the length of time you want it to continue taking pictures. At the end of the elapsed time (you can interrupt it earlier if you wish) it combines the individual JPEG files into an mp4 video. It also saves the individual JPEG files, so you can process them separately.

Previously I have used a GoPro (built in interval timer), a RaspberryPi (uses cron as an interval timer), or a DSLR with an external Interval Timer to make time lapses. Interval timers are available for a variety of cameras and are relatively cheap (around £13). The Amazon link shows the one I use with my Canon DSLR. Amazon link to interval timer

You will also require some sort of stable mount for the camera. Traditionally this would be a tripod. However, I like making time lapses in the mountains and don't really want to lug 10kg of tripod for several hours up a mountain in addition to all my camping gear. If the terrain is rocky you can usually find a convenient rock or trig point which you can use to perch a mini tripod. If the ground is grassy I have a lash up of various GoPro adaptors attached to a walking pole, which I push into the ground.

Making a time lapse of a sunset or sunrise requires quite a lot of planning and a lot of luck with the weather. First you need to work out what time the sun rises and sets. Most smartphone weather apps will have this information. Secondly you will need to find a location that provides an unobstructed view of the horizon. Bear in mind that the sunrise and sunset will move across the horizon between the two equinoxes according to the date.

Next you need to decide on the time interval at which you want to take a photograph. I have found around 5 seconds to work for me. It doesn't matter if you take too many photographs, but it does if you don't take enough! I would suggest that you start recording at least an hour before sunset. It's also worth continuing to take photos for at least an hour after the official sunset time. Once the sun has gone below the horizon you will often get an alpenglow effect, which can last quite some time.

You should now have an SD card with hundreds of images on it. There are a number of methods of creating an mp4 file from the images. I use a combination of ffmpeg and mencoder. I think these are available for most platforms, they definitely work on Linux and Mac OS. Ffmpeg is the Swiss Army knife of video processing tools. It's under constant development and the developer has been known to change the syntax of the command line options at a whim.

This is a link to "FFMPEG An Intermediate Guide/image sequence":

https://en.wikibooks.org/wiki/FFMPEG_An_Intermediate_Guide/image_sequence

I use ffmpeg to combine the individual jpegs into an mp4 video. Your jpegs will almost certainly be numbered with a suffix that increases by one for each successive photo, so you can automate the process using a script or batch file.

Once you have created the mp4 you will probably find the mp4 file created from several hundred jpeg images is only a few seconds long. You can use mencoder to create a slow motion version of the mp4 video. Finally, you may want to add some background music to your video. You can use ffmpeg to add an mp3 track which adds the audio, but stops when it runs out of video to process.

For full details about creating mp4 files from individual JPEGs, slowing down the video and adding an audio track see my blog post at:

Concatenating JPEG Files Into an mp4 File.

Tools required:

  • ffmpeg
  • mencoder

  • sox

    If your JPEG file names end in a number, you can use the "-startnumber" command line option: 

      ffmpeg -start_number n -i test_%d.jpg -vcodec mpeg4 test.mp4

G0010024.JPG 

  ffmpeg  -start_number 10024 -i G00%d.JPG   -vcodec mpeg4 test.mp4

Note, this will work as long as the sequence is unbroken once it starts. If there are gaps and you want all of the stills included, then renumbering may be necessary to fill the gaps.

GoPro ffmpeg Command Line.

This is the script I use with my GoPro. It creates a 1080p file from a JPEG. The %d is a placeholder for a number, so files starting from G0017096.JPG will be concatenated to make the video. 

   ffmpeg -f image2 -r 1 -start_number 17096 -i G00%d.JPG   -s hd1080 -vcodec libx264 timelapse_1080P.mp4

Using mencoder to Create a "Slow" Version of the Video.

This example slows the video down by 50% at 25 frames per second. 

 mencoder -speed 0.5 -ofps 25 -ovc copy Flapse_25fps.mp4 -o slower.mp4

Adding Background Music.

There are several ways to do this. If your video is longer than the background music track, you probably want the music to loop until it reaches the end of the video.

I'd recommend sox and the -shortest option for ffmpeg as a solution. 

 sox -i short_audio.mp3 looped_audio.mp3 repeat 1000 # adjust count as necessary
 ffmpeg -i input_video.mp4 -i looped_audio.mp3 -shortest output_video.mp4

The sox command will loop the input, and the ffmpeg command will use it for the audio, but stop when it runs out of video to process.

-i parameter is deprecated in sox. Is is properly to use -e ima-adpcm instead.

There are several sources of free background music on the Internet. For example: background music