low-light.md

Low-Light / Night Operation

Important controls:

--framerate
--shutter
--gain
--denoise

General tradeoffs:

• Lower frame rate permits longer exposures, improving brightness but increasing motion blur.
• Higher gain increases brightness but also increases visible noise.
• Denoise can reduce noise but may reduce fine detail and add processing.

Check the denoise modes supported by the installed version:

rpicam-hello --help | grep -A3 denoise

Automatic 30 fps starting point

rpicam-hello -t 0 \
  --fullscreen \
  --qt-preview 0 \
  --framerate 30 \
  --viewfinder-mode 1920:1080:12:P \
  --viewfinder-width 1280 \
  --viewfinder-height 720 \
  --buffer-count 2

Manual exposure example

Example only:

rpicam-hello -t 0 \
  --fullscreen \
  --qt-preview 0 \
  --framerate 30 \
  --viewfinder-mode 1920:1080:12:P \
  --viewfinder-width 1280 \
  --viewfinder-height 720 \
  --buffer-count 2 \
  --shutter 20000 \
  --gain 4

--shutter 20000 requests approximately 20 ms exposure. Tune shutter and gain for the actual environment.