Abstract Photographer Research

I was looking up some artists that were abstract for inspiration/to see what the pros do. One of the favorite I came across were Tony Sweet. He uses nature photographs for almost all of his abstractions. He creates beautiful tones through the pictures. He also uses a lot of long exposures, which I love. He creates more of a flowing feeling through the nature with creates a smooth natural feeling. He plays with a lot of depth of field a lot and it makes for very interesting photography.
http://www.tonysweet.com/page_gallery.html
I think that I loved his abstract photography because it was different to me. He plays with shutter speed and aperture which I haven't seen as much with abstractions. He seems very skilled technically, knowing his camera very well.