The château and gardens of Chaumont-sur-Loire have an impressive range of artworks and installations among the historical displays. I particularly liked the work of Toshio Shimamura. His flower pictures seem so much like a perfected version of what I have been groping towards. Here is an example of his tulip pictures, where the dying flowers take on a deeply unsettling appearance.
Another interesting set of images by Marie-Jésus Diaz was focused entirely on the skeletal silhouettes of trees in winter – she also uses Photoshop to create patterns imposing a kind of symmetry without destroying the natural appearance of the images, as in this example.