In 2008 I was contacted by independent artists and editors Juan Batalla and Dany Barreto to collaborate in a multidisciplinary investigation on the Umbanda religion in the River Plate area, that is, Argentina and Uruguay. The result was a book named "Owners of the Crossroads." I was in charge of the photography of both the ceremonies (those we were allowed to watch) as well as the altars, which I found particularly interesting. These are the sites where food and other gifts are traded to the divinities in exchange for favors asked or received.
Contact me if you are interested in the book.