Darkening of the image from the OV9281 camera when shooting 240 fps 640x400

[aksion2011]

OV9281 camera with Nvidia jetson orin nano

I have a normal light monochrome image at a resolution of 1280x720@80fps.
When I set 640x400@240fps the image becomes very dark, how can I fix this?

Command to run:
ffmpeg -f video4linux2 -video_size 640x400 -framerate 240 -i /dev/video0 -vf vflip video.mp4

image is dark

Im try change this options:
v4l2-ctl -d /dev/video0 --set-ctrl=exposure=50000 --set-ctrl=analogue_gain=1500

But this didnt produce any visible effect.

[ShaneCCC]

Do you confirm the sensor gain/exposure setting by dump the REG?

[aksion2011]

Yes, but maybe I’m doing something wrong.