Image manipulation started as early as the 1850’s, with such photographers as Oscar Gustave Rejlander’s “Two Ways of Life”. Here is a good link to learn more about Rejlander. The key issue here is that fine art photography started its life and the photomontage quickly became a tool of photographers. “Straight out of the camera” and “no manipulation” have long been lines of contention in photography. With criticisms coming from within the photographic community and from the “Other Arts” community.
Again I make the distinction that for some types of photography no modification (except for that required in scientific endeavors for specific purposes) is acceptable. But for Fine Art Photography, it is my belief that all forms of manipulation are fair game. I have a quote that for me defines what this is, “The Heart of Art Lives in The Soul of Man”. It has nothing to do with reality, but everything to do with what make your soul smile.
For me its ok to have various lines of photography vision – from groups like F64 to those who image with no preconceived paradigm to follow. For me the “straight Out of The Camera” is not a badge of purity but one of many valid visions of what photography is.