A photograph is treated as evidence in a way that a sentence is not.
That survives even though every reader knows images can be altered.
therefore operates under rules that written reporting does not need.
Adjusting brightness is permitted; removing an object is not, and the line is defended strictly.
Agencies have withdrawn prizes and ended careers over a removed shadow.
The harder problems are not about editing at all.
decides what a viewer believes about a scene without altering a pixel.
A crowd photographed from one side looks large and from the other looks thin.
is the second question and it has no clean answer.
A person in a disaster cannot meaningfully agree to be photographed, and the photograph may be what brings help.
therefore ask whether the image would be taken if the subject were the photographer's neighbour.
It is a weak test and it is better than the absence of one.
images have now entered the argument from a new direction.
The danger is less that a fake will be believed and more that a real image will be doubted.
Agencies have responded by recording where and how each image was , which is a claim about process rather than about pixels.