Stefan, I'd take issue with some of your points there:
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"Although I don't mind altering the brightness and contrast of a photo, or cropping it to a suitable format, but rearranging the composition is just wrong."
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I don't think so at all. For example, let's say I'm photographing three beer bottles lined up on a wall. What difference does it make if I swap the order of those bottles by hand, and then take the photo, or if I take the photo, and then swap their order in Photoshop?
That's certainly a simplification of the situation, but it's fundamentally the same thing - if you alter anything post-shot then you're manipulating the image. There are degrees of manipulation, sure, but it's all manipulation.
And as for it being wrong, well that depends on your aim. If your aim is to produce as good an image as possible, then manipulation (in whatever form) is acceptable. If your aim is to shoot what you see, and only what you see, and to never burn or dodge, and never be tempted to alter the contrast in the darkroom (digital or otherwise), then sure, I get your point. But in the world of professional photography it's not a very realistic one.
When the people at Getty Images decide if they want a photo of mine they don't ask how it got to look like that - they couldn't care less - they're only interested in the quality of the image.
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"It is not like I don't like photo's that are rearranged, but just don't call it a photograph. It's a bit (dare I say it) degrading to the profession."
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I'd be very, very surprised if you could tell me a top photographer who's never manipulated one of their photos; never dodged or burned, never removed an offending object, never selected a processing chemical or film type or filter in order to 'manipulate' the real life scene and produce what they could see in their mind's eye.
It helps to have a broad mind regarding what photographers are doing now a days, and also to forget the idea that top level photographers won't ever have done similar things (technology allowing). Sure, what I've demonstrated doesn't follow a puritan, or dictionary definition of 'photography', but it certainly falls under the modern (and commercial) definition.
I do photo manipulation for a couple of guys who epitomise the title of 'professional photographer'. They lug around giant panoramic cameras, and tripods that weigh a ton. They take 15 minutes exposures to get giant depths of field. They'll travel to New Zealand once a year for three years to get the perfect shot of something. They make a packet and produce beautiful images.
They are most certainly professional photographers, but you can bet that when I offer to remove a vapour trail, or turn a factory pipe with steam coming out of it into a factory pipe with black smoke coming out of it, or whatever their brief demands, they will jump at the chance.
If you'd rather people called manipulated photos 'digital art' then I guess they could, but the only place you'd ever see anything labelled as a 'photo' again would be at an amateur photo club gallery.
Personally I've grown up with photography and manipulation hand in hand - I think I did my first 'head-swap' when I was 15 (12 years ago) - so the idea of altering a photos details after the fact doesn't bother me. My aim is to have the finished product look as good as possible, how I get there is of little consequence to me. Sure I'd prefer to get the perfect shot in one go, direct onto 'film', but that's not always possible.
All that said, I do get your point about the name of 'photographer', there'd be a certain point where your images couldn't claim to be 'photos', but I think that point is blurring. I still see my images as photos. Manipulated photos, sure, but photos none-the-less.
Is that a lazy use of language? Maybe. But I think it's an increasingly popular one.
Gosh, what a long comment :o)