Where is the end of Photography and where the beginning of art?
Nowhere. I already said it under the menupoint "composing", there are people who say that everything which is not "out of cam" is no photography any more, but in my oppinion that would go too far. Photoart is a result from photography, without photography there would be no photoart. The same as essays, lyrics, novels and reports are literature also "out of cam", composing and photoart are photography.
There are so many ways to create art. The pattern of peeling paint itself can be art, you only have to see it and take a photo. Even to move your camera while shooting can be art if it makes a special effect that you want to add to your picture.
The same as you can paint colour with a brush, with a spatula or just pour it in painting you can work in photography with different techniques. The word photography comes form "painting with light" and there are different ways to paint with light.
Pavel Kaplun (several people will know him) is the master of "marmeladizing". Some people say that his works are no photos any more. There are no limits to creativity. As long as you use something to add a new feeling to your work it is art. And as long as we paint with light it still is photography.