Pitfalls of using photographs by others

The painting (above) was done using photograhs that I didn't take. I seldom resort to that but occassionally there is no option but doing so poses certain problems. Not because of a lawsuit as my painting ends up far from being close to the photograph. The problem comes with lack of information even with a good photo seems to provide. Here is an example.
The first picture (below) shows the rocks but gave me no indication of where they jutted in and out. I assumed they didn't have much direction at all. I started the painting using the first photo and then found this second photo which defined the crevises with light and shadow more clearly. Had I actually been at the lighthouse (wish I could) even for a minute I would have grasped and understood the topography that the first photo simply didn't express.
So, even if you work from photographs, doing so from your own photos will result in a much clearer undertsanding of what you are trying to portray. It only takes a moment for those important features to stick in your mind when you take your own pictures.