I frequent 500px and enjoy viewing and voting the photos there. I thought I was mostly looking at photography on this site but it seems that my eyes were fooled more then a few times. (And this is not specific to 500px but other Photography sites as well) I am not talking about obvious "traditional" photomontage but rather images that almost seem to pose to be "real" photos.
Personally, I feel a bit tricked by these "photos" especially when seeing all the other users' comments who obviously think they are seeing "photography". (I am deliberately not linking specific photos) Doesn't this sort of thing belong to digital art or even digital rendering along the lines of Povray?
As for 500px, I was under an assumption that this site is for photography. To quote a few references; "500px.com: World's Best Photographs" and "500px is Photography"
I don't doubt that some photomontage is art but does photomontage belong in photography?