Things I study.

"It seems positively unnatural to travel for pleasure without taking a camera along. Photographs will offer indisputable evidence that the trip was made, that the program was carried out, that fun was had.
Photographs document sequences of consumption carried out outside the view of the family, friends, neighbors. But dependence on the camera, as the device that makes real what one is experiencing, doesn't fade when people travel more. [...] A way of certifying experience, taking photographs is also a way of refusing it - by limiting experience to a search for the photogenic, by converting experience into an image, a souvenir. [...]
The very activity of taking pictures is soothing, and assuages general feelings of disorientation that are likely to be exacerbated by travel.
Most tourists feel compelled to put the camera between themselves and whatever is remarkable that they encounter. [...]
The method especially appealss to people handicaped by a ruthless work ethic - Germans, Japanese, and Americans.
Using a camera appeases the anxiety which the work-driven feel about not working when they are on vacation and supposed to be having fun. They have something to do that is like a friendly imitation of work: they can take pictures."
Susan Sontag: "On Photography", St.Ives 1977, S.9f.