When I toggle on the lens of truth, everything turns black, but it fixes when I look anywhere between northeast and southeast. Below is my save state so you can see what I’m talking about.
I think its a light issue, because if you went into first person with the lens, you would be able to see the ice glowing on the other side of the canyon.
Thanks for reporting the problem you ran into. This one is tricky and very specific. I’ll see if I can attempt to recreate and then fix the problem if possible.
So, the lens of truth makes invisible things visible, the bug makes things completely dark when using it. The bug happens when the camera faces an invisible object with the lens is activated, the cardinal direction isn’t involved.