The questionis it a photograph?
Every page on this site was written to be checkable. This one is different: it asks the only question here that measurement cannot settle, and it does not answer it. Both cases, as honestly as they can be made.
The case for
The exposure accumulates and converges, and its grain obeys the same square-root law film obeys, because both are counting arrivals.
There is a negative, and it is never retouched. Development happens afterwards and can be repeated, argued with, done better.
The glass is real glass: traced from its own patents, faults and all, refusing to flatten fields it cannot flatten. Nothing soft was made soft on purpose.
The subject is deterministic. The same few lines produce the same structure for anyone who runs them, on any silicon, forever - and that, rather than who first wrote them down, is what makes it a thing photographed rather than a thing drawn. Most were found. One was written on purpose and is exactly as fixed, exactly as unretouchable, and exactly as able to refuse what its author wanted.
Prints exist, in editions, on paper, and two prints of the same negative can disagree exactly the way two darkroom prints disagree.
The case against
No light ever travelled. Nothing was ever in front of anything.
The subject has no location, no moment, no witness. There was no instant at which the photograph was taken, only a computation that ran until it was stopped.
The camera has never been built. It is a description of a camera, exact enough to behave like one, which may not be the same thing.
Reproducibility itself is the tell: a photograph of the world is unrepeatable because the world moves on. This does not. A thing that can be re-earned identically might be a proof, or a performance, but a photograph?
The word might simply be borrowed, the way a synthesizer borrows the word organ.
The instrument is specified. The photograph is in your hands. You decide what it is.
Where these arguments come from
None of the cases above is new, and it is only fair to say whose they are. They are stated here in this practice's own words rather than quoted, so these are the positions the two columns are standing on, not sources for any sentence in particular.
Bazin, “The Ontology of the Photographic Image” (1945), in What is Cinema? vol. 1 - the photograph as an image formed automatically, and the claim that photography alone among the arts profits from the absence of the person making it. The case for, above, runs on an automatism built rather than inherited.
Barthes, Camera Lucida (1980) - the photograph's that-has-been: what makes it a photograph is a real thing having stood before the lens, and a past moment the picture certifies. That is the sharpest form of the case against, because here there is no such thing and no such moment.
Scruton, “Photography and Representation” (1981) - the argument that a photograph stands to its subject in a causal relation rather than an intentional one. Scruton's subject is an ideal photograph he describes as a logical fiction, so his conclusion is about a limiting case rather than about any print you could pick up.
Walton, “Transparent Pictures” (1984) - the opposite verdict on the same causal chain: photographs are transparent and we see through them, the way we see through a telescope or a mirror. He means the seeing literally, and the mirrors and telescopes are his.
Hasinoff, “Photon, Poisson noise”, in Computer Vision: A Reference Guide (2014) - the one measurable sentence on this page. Photon arrivals are Poisson, so the signal-to-noise ratio grows as the square root of the count, and the same independence of arrivals produces the grain in film and in a sensor alike.