This is even more true when I'm working with water as the subject. I use this sort of detail by setting up an exercise that can make a sort of accidental paint equivalent to the detail in the photo. Another way I am increasingly using photos is the computer darkroom. Scanning a negative and then stretching combining colour-adjusting and so on in Photoshop allows for a greater scope than I had before. The whole exercise of painting is to start with a subject and to take it through a whole heap of processes which take it further and further away from the source until almost magically the painting arrives back where it started and the artist realizes he has learnt a bit along the way.
Cameras only supply one step.
The history of landscape in the West is considered to start around 500 years ago. I often look to for understanding of what landscape is really about. Paintings from the Chinese masters typically show large torturous mountains disappearing into mists with placid streams and fields lying at their feet with perhaps a couple of peasants working in them. The cosmic view is one of acceptance of the vastness of nature and the small position we occupy below the heavens. Although this is still a valid viewpoint 1,700 years later, the prevailing cosmic view seems to be more that we are an incredibly crowded planet with diminishing natural resources in a vastly expanded universe of galaxies.