OpenCamera and Camera2API can't access a certain camera, but a 3rd party Gcam port can. Why is this?

[Victor Lin]

I have the LG V50 V500N on the latest Android 10.

On the back it has three cameras:

26mm 12MP main (Camera 0)
16mm 16MP ultrawide (Camera 2)
50mm 16MP telephoto (does not show up on Camera2API)

The telephoto does not show up anywhere with Camera2API, and I'm unable to access it through OpenCamera and Filmic Pro, as expected.

But the strange thing is that I can access it using a 3rd party Gcam port with an additional XML config file.

But I'm confused. How is a 3rd party Gcam port able to access the 50mm camera when it's not even reported on Camera2API? Shouldn't it be absolutely invisible to any kind of 3rd party app?

I confirmed that the telephoto was indeed being used (and not a digital crop of the main) by placing my finger over the physical lenses to make sure that I was shooting with the telephoto.

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Urnyx's 7.3 v2.1: GCam with a V50 config file:

https://www.celsoazevedo.com/files/android/google-camera/dev-urnyx05/
LGV50_DenniztheMenace.xml

Here is the Camera2API report for reference:

In spreadsheet format: https://docs.google.com/spreadsheets/d/1trOn2Byjz_A5zp4XJA6vcFUDZWR19B7TSmwcmiOswLA/edit?usp=sharing

In text format:
https://docs.google.com/document/d/1JdSf1uUr9DVjuj893Sr3wS4u6h3vdEFYAczhgD-tVv0/edit?usp=sharing

[Victor Lin]

Edit: Being able to access the telephoto camera in gcam seems to be a built-in feature of this gcam port. It has options to enable "auxiliary cameras" and that includes the telephoto that is normally invisible to Camera2API and all other 3rd party apps including OpenCamera. But I don't understand how this is possible?

I'm not rooted.

Gcam https://imgur.com/a/NH9On6M