When you get close to an inscription (or any photo-worthy scene), you'll see a camera icon pop up in the upper left corner of your screen.
If the fuzzy brackets are inside of the solid ones, that means your subject is too small and you need to either get closer or zoom in.
Once you get the brackets aligned, you'll get a take picture prompt on the screen.
After buying the camera from Ernesto, you need to follow specific directions to find each of the four Strange Inscriptions.
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