Record less than 10 seconds with a camera

[vestal echo]

Hi there! I want to generate a short ~4 second video clip from my doorbell camera whenever someone presses the button, however it seems like even if I set the duration to 2 and lookback to 2, the recording length is still 10 seconds. The stream is active (to allow lookback) but it's always 10 seconds

  - action: camera.record
    metadata: {}
    data:
      filename: "{{video_local_filename}}"
      lookback: 5
      duration: 2
    target:
      device_id: 91ffdc64256cb56a4bdc2067569c946d

[vestal echo]

It seems like record always takes a while, even if there is less time in the future?
Even with a duration of 2 seconds and a lookback of 8 (resulting in a 10 second video), the step still takes 4 seconds