EOS R6 Mark III S&F vs M video size; P vs M when switching to stills

[XLI]

Is there a reason 120fps video takes up less space when shot in M mode, even though it includes sound, compared to S&F mode when shot at the same resolution and codec etc?

Also, regarding S&F mode: is there a way to change the mode it switches to when changing over to stills? Right now it defaults to P mode, but I would prefer it to switch to M mode, or at least have a way to choose the preferred mode. If this isn’t currently possible, could it be addressed in a future firmware update?

[shadowsports]

Greetings,

Check your settings.  When you shoot in 120fps, the camera uses IBP compression by default.  In manual mode IBP lite is used so the captured movie quality is lower. (smaller file)

When the camera is mode dial is set to S&F this option only works in movie mode.  If you change the camera to stills mode the S&F setting on the mode dial is ignored and the camera activates the last used still shooting mode Fv, P, Tv, Av or M.  

[XLI]

Compression method is set to Standard LGOP on both modes.

Also, the camera doesn't activate the last used still shooting mode – it just defaults to P.