Get LUX value for Cordova app

Question

I'm implementing a Cordova App for Android and iOS. I want to get the LUX (illuminance) value.

I'm not sure if my phone has a device light sensor (or do all smart phones have them these days?) - I tried "window.ondevicelight" but it wasn't triggered.
I also tried https://github.com/MangoTools/cordova-plugin-lightSensor but the returned values seemed not sufficient to me (wether i held it against the sun or put my hand in front of the lens similar values appeared..)

Is there another plugin for Cordova that I don't know of? Or is there a way to access the ISO/ Aperture/ Shutter Speed values from the mobile camera, to calculate LUX?

Any help would be appreciated!!