The island must have drinking water, tropical, cold, dry, mediterranian, etc climate to get raw ingredients from it. Most uninhabited islands are this because there is no drinking water, so, the short story will have to be a supernatural one, that is an island inhabited but with people who know nothing about photography and have this paradise with, of course, a volcano:
Hawaii before the arrival of the white men.
A door is open under certain conditions, it could be atmospheric ones or psycological ones, supernatural ones, but you will have all you need in it.