Exposure Control for other UVC Webcams

We are using an ArduCam B0454 UVC compliant webcam this season and have enjoyed the enhanced VisionPortal and CameraControls (thank you!).

We are setting the exposure manually and noticing that there does not seem to be a clear mapping from the numbers we are passing in via exposureControl.setExposure(exposure, TimeUnit.MILLISECONDS) and the camera's behavior. For example, a value of 1 for "exposure" in the previous call results in a fairly typically lighted image while a value of 2 _reduces_ the brightness considerably (implying a _shorter_ exposure time). This trend continues as the exposure value increases. getMinExposure(TimeUnit.MILLISECONDS) and getMaxExposure(TimeUnit.MILLISECONDS) return a range of 1-204.

We have this data from the manufacturer: https://docs.arducam.com/UVC-Camera/Adjust-the-minimum-exposure-time/ Its tempting to think that the "exposure" value used in setExposure() is being passed directly to the CAP_PROP_EXPOSURE property but with the sign flipped. However, we are fairly confident that the actual exposure time with an exposure value of "1" is considerably less than the 500ms the linked document suggests.

Is there a way to address this, or perhaps a way via the SDK to bypass ExposureControl and set UVC properties on the webcam directly?