I had this debate wth a fine artist many years ago, who'se opion was pretty purist, and a 'photo' should remain a traight record of photo-reality and ANY manipulation was frauding the viewer.
To which I replied that 'Photo-realism' and the notion that 'the camera never lies' is a myth; the camera ALWAYS lies... and it starts long before any post-process diddling.
Before you press the shutter, you have the dilemah whether to use a slow shutter and blur motion, or a wide aperture and effect a shallow focus. NOTHING shot with 'flash' is depicting a 'real' scene you would see with the naked eye, etc etc etc...
In the poineering era, a lot of what are now common manipulations, were used to ahieve a 'perception' of photo-realism the equipment and materials they had to hand didn't allow... such a magnesium flash lightig, or the use of posing stocks to hold a sitter still durng a exposure, or... re-incented in modern times as HDR, merging seperate exposures for shaddow and high-lights to make a print.. WHICH.. is actually a re-invention of what was a common practice amongst 'fine art' practicioners, who made a final painting, not from a 'real' scene but from sketches of diferent elements....
I believe that art historians have been debating for decades over 'where' Constable painted the Haywain... unable to locate any where that a ford runs infront of a cottage in such a 'flat' region devoid of hills n the back-ground... and that concensus is that the final painting was almost certainly created in the studio from seperate sketches of the cottage, the river, the cart the carter, the sky and trees, that 'scene' even in small part 'never' actually existed...
So.. where do you draw the line? How can you say, 'yes', it's fine to make an entirely artifical, but aparently 'real' image with a paint brush, but 'oh no!' you MUST not try and 'fool' the audience making an entirely artificial image with a Camera... because the 'audience' have a presumption that the camera never lies?
Takes the debate off into a new area, where it is not a matter of symantics, and what may or may not be 'acceptabe practice' but one in which it is the relationship between the creator and the viewer and the intent of the creator.
And even if there is intent to decieve in creation, that does not necesserly deminish the 'art'! People pay to go see magicians KNOWING that they are going to try and decieve them.. that IS thier whole 'art'! And not knowing how they have been decieved a large part of the spectacle.
In photography? The 'fraud' comes right at the start, with the viewers perception that what they are looking at 'should' be photo-realism.... the myth that the camera never lies.
A-N-D, on that presumption, I HAVE to say that photo-shop has done wonders to STOP viewers making that automitic assumption!
It is revealing that the modern obscession with 'sharpness' and digital clinicity combined with ever higher resolution micro sensor cameras has resultd in a phenomina where subjects may be rendered with such aparent 'sharpness' in a scene, that they appear detatched from that scene, and viewers will look at that image and insist that the subject 'must' have been photo-shopped in to what IS actually a 'straight' photograph....
The increased commonality of image manipulation has done a awful lot to break the presumption that a 'photo' is an accurate depiction of reality, to the point that it s NOT automatcally assumed, and even a 'straight' photo displaying the sort of inherent anomoly created 'in-camera' is accused of having bee 'diddled'.
This makes it that much more dificult to use that viewers assumption to fool thier perception, and may beg a even greater dgree of 'diddling' to achieve the sort of photo-reality that a viewer would expect.... conversely, that presumtion deminishd, any image that doesn't display the preumed level of photo-reality becomes, is more obviousely prsented to be judged on its own merit as an image, like Constable's Hay wain, or a magician's rabbit from the hat... the means of creation becoms less important, the response of the viewer, whether they are deligtd by what they see, whether they question what thy see, all becomes seperated from the actual means of creation, and the question "How did you do that?" merely ONE of the possible responses you might envoke in the viewer... which may or may not add or detract from the image, and we return to the intent of the creator and their relationship with the viewer....
A large chunk of my photgraphs are technical illustrations, trying to display what an obscure bit of the inside of a motorbike should like, and how to put them bits together... this is far from 'art' photography, trying to deliberately manipulate emotions... and the presumption of 'photo-realism' is used... synically!
People see a photo of a spark plug they dont expect that to look any different in real life... YET to concentrate the viewers attension on the condition of the electrodes, that image will use a scale and selective focus, to make obviouse what they should be lookig at... not what they would actally see for real with the naked eye; trying to show where a cam-chain tensioner bolt is to be found on the back of an engine, again, atifical light will be used to actually light it up, selective focus will be employed, they dont 'need' to see the detail of finning on the cylinders, or the casting marks on the cam cover! And I will 'clone out' destracting detail, like say a temperature sender wire, or a clutch cable or 'something' that isn't intrinsic to the message I am tryng to convey, "This is a cam-tensioner bolt! This is what it looks like! This is whre you will find it! Follow instructions to tension the cam-chain!" The 'photo' is synically lacking 'photo-realsm' it is NOT a faithful reproduction of the subject I took a photo of.... do I care whether the viewer believes it is, or should be? Or do are that they have found the right bolt to twist, and not mistakenly undone the wrong bolt and dropped the oil-pump into the sump instead of stop thier tappetes tapping! Have I defrauded the viewer some-how, even if they believe what they are looking at is an absolutely 'faithful' photographc image?
I cold convey the same message in more conventional non photo-graphic means; technical dawing, obviousely not photo-realistic, but imedietly abstract, the viewer has to try and interpret that line drawing to the actual artifact. Sometmes that 'may' be mre apropriate, and using scrap-sections or detail segments, or exploded diagrams, thse 'may' better illustrate the situation, of the real world to the viewer... but, they remain obviousely abstract.. this does not make them any more or less 'honest'.. NONE of the images are particularly 'Honest' they are ALL trying to comunicate with the viewer.... and in this sort of instance, that can be pretty easily measured; "Dd you fint the cam-chain-tensioner bolt? Did you manage to stop your tappets rattling?" DID the image convey the message, did it do the job?
Moving away from that use of photo's for illustraton, where they are a tool, into the art arena where they are their own message.... the intent, the anticipated viewer response, may be anything, from making them gasp at the aesthetic beuty, to gasp wth revulsio, laugh at the humour or question what they are looking at or the world arond them, but still, the question is "Did it do the job?" NOT "How did you make that?"
IF they actually ask how you made an image.... you have probably failed.... whether for art or illustration, that shouldn't matter.. merely the 'message' communicated.
Now submit a photo into a photo competition..... the same deal still applies.. its the relationship between you, the creator and the viewer, and the viewer, the judge (or panel of).. what is the remit of the competition? What are the rules of the competition, and what is the purpose of the photo? And the specification may be quite perverse and obtuse,,, and the ultimate judging criteria significantly detached from the published rules and requirements...
Back to the cam-chain-tensioner bolt.... twenty odd years ago, building motorbikes for racing... objective s simple... cross the finish line first! Rules often quite stringent; Quirky anomaly for you, for the 500cc class, in the 'open' class, that was the hard limit for the engine displacement; bore an engine out to over 500cc, it didn't qualify. But in the 'production' class, an engine could be built to 'blue-print' regulations, where if the manufacture allowed for a 're-bore' as a normal service procedure, an engine that might have displaced 490cc when sold in the show room, could be bored out to perhaps 540cc for racing.... at least in the proddy class... but that '500' class bike wouldn't technically comply with the 'open' regs.... B-U-T.... if you entered that bike in both proddy and open classes? And got a scrutineers ticket for it, would you get caught racing it n the 'open'? Where the 'rules end how much may you get away with in the margins?
Taking that bit of 'snaky' or down right 'cheating' into the realms of the academic assignment or the photo competition.... there may be as much in your 'interpretation' of the rules, and how far you are prepared to go, bending or breaking them, in achieving what the judge hopes to see, as there is in diligently adhering to the rules.... especially if they are looking for that interpretation, that ingenuity, that 'creativity' or simply bravery to push the boundaries....
A-N-D we are back to it being all down to the relationship between the creator and the viewer, the creators intent and the viewers expectations....
Post-Process manipulation remains just one legitimate 'tool' in the creators armory, in the same way that 'doped fuel' is a legitimate tool making motorbikes win races.... whether you want to use it, whether you are allowed to use it, whether you may get away with using it... ALL comes down to that relationship between creator and viewer.... an is entirely circumstantial, within the circumstances of that relationship.
