Some people say that you should leave the photos as they come out of the camera, no post software no alterations of any kind, well maybe just a little contrast and that’s it, and why is this i ask?, well because they say so and that’s it, most of the time it’s because somebody says that that is the way is suppose to be, but if you ask them why they just leave in frustration because they don’t know the answer.
The only real restriction is imposed by magazine or newspaper photo editors is that they want their readers to see a photo that is a real representation of reality not something altered in photoshop, so they impose certain rules on any photographer that is working for them, same goes for magazines like national geographic, and if they are the bosses who will accept or deny your photos then you better obey.
But if you are your own boss and you take pictures because you think you are an artist or you are sure you are one, then there are no restrictions to your art, as long as it really is a reflection of what you want to transmit to a viewer, you are the artist and your art has no restrictions, whatever you want to do you can do, as long as it does not hurt anybody or anything or any company.