Creating timelapses with Fujifilm and FFmpeg

Notes on capturing interval sequences with a Fujifilm camera and assembling them into smooth timelapse videos using FFmpeg.

Camera settings (Fujifilm)

Before beginning the shoot:

Image quality: Set photo quality to JPEG (Fine or Normal depending on SD card space) and aspect ratio to 16:9 to match video output.
- Tip: Remember to restore your standard shooting settings (e.g. 3:2 RAW) once the timelapse session is complete.
Interval timer shooting:
- Navigate to INTERVAL TIME SHOOTING in the SHOOTING SETTING menu (camera icon).
Interval and shot count:
- Interval duration: The time between each shot. Check the camera’s estimated remaining shot count on your SD card and divide by your planned session length to determine the fastest safe interval.
- Number of shots: Set to infinity ($\infty$) or your target count.

Assembling with FFmpeg

Once the photos are transferred to your computer, use ffmpeg to encode the sequence.

Daytime timelapse (with frame skipping)

For a 60 fps daytime video where you want to drop every other frame (effectively doubling the playback speed):

ffmpeg -r 60 -pattern_type glob -i "*.JPG" -s:v 1920x1080 -c:v libx264 -pix_fmt yuv420p10le -vf "select=not(mod(n\,2))" s1080r60skip2.mp4

Stargazing / Night timelapse

For night skies or astrophotography where you want lower framerates and maximum fidelity:

ffmpeg -r 15 -pattern_type glob -i "*.jpg" -s:v 3996x2664 -c:v libx264 -pix_fmt yuv420p10le -crf 18 stargazing.mp4

Parameter breakdown

Parameter	Purpose
`-r 60`	Output frame rate (e.g. 60 fps or 15 fps).
`-pattern_type glob -i "*.JPG"`	Reads all JPEG files in the directory in alphabetical/chronological order.
`-s:v 1920x1080`	Sets output resolution. Use a lower resolution for quick test renders, then full resolution for the final cut.
`-c:v libx264`	H.264 video codec for broad device compatibility.
`-crf 18`	Constant Rate Factor. Lower values yield higher quality; `18` is visually near-lossless (default is around `23`).
`-pix_fmt yuv420p10le`	10-bit YUV 4:2:0 pixel format, providing smoother gradients across skies and gradients without color banding.
`-vf`	Video filter chain (see below).

Video filters (`-vf`)

Filters can be combined with commas:

Frame selection:
- select='not(mod(n\,2))': Keeps every second frame.
- select='not(mod(n\,4))': Keeps every fourth frame.
Fade in / out:
- fade=in:0:30: Fades in from black over the first 30 frames.
- fade=out:1524:30: Begins a 30-frame fade to black starting at frame 1524.

Example combining frame skipping and fades:

ffmpeg -r 180 -pattern_type glob -i "*.JPG" -s:v 1920x1080 -c:v libx264 -crf 18 -pix_fmt yuv420p10le -vf "select=not(mod(n\,4)),fade=out:1524:30,fade=in:0:30" s1080r180skip4crf18fade.mp4

Concatenating multiple sequences

To join multiple rendered clips together without re-encoding, create a concat.txt file listing each segment:

file 'part1.mp4'
file 'part2.mp4'

Then concatenate with stream copying:

ffmpeg -f concat -safe 0 -i concat.txt -c copy combined_timelapse.mp4