VideoCapture1.Video_CaptureDevice_VideoAdjust_GetRanges( VFVideoHardwareAdjustment.Brightness, out min, out max, out step, out defaultValue, out auto);
Use Video_CaptureDevice_VideoAdjust_SetValue to set the necessary level.
VideoCapture1.Video_CaptureDevice_VideoAdjust_SetValue( VFVideoHardwareAdjustment.Brightness, tbAdjBrightness.Value, cbAdjBrightnessAuto.Checked);