adjust webcam brightness

Hi, I'm running Ubuntu 18.04.4 (Linux 4.15.0-136-generic x86_64) on a Dell desktop. I just got a webcam, ID 1224:2a25, and the picture on zoom and webex calls is too bright, into saturation.

Both uvcdynctrl and v4l2-ctl can't find any controls for this device.
v4l2-ctl -D says (not using libv4l2), driver uvcvideo

uvcdynctrl -c says :
no controls found

Does anyone know how to access the video settings for the camera?

Thanks,

Jon