I have been considering the impact of electronic imaging on the burden of visual truth. When a photographer uses layers of two identical images that are exposed differently to make a new image would this constitute digital manipulation? Years ago in the darkroom we would call this technique sandwiching. You would take two negatives with different exposure values to make a correction. Granted this practice was not widely in use, but it did exist. Today, thanks to digital technology, the latitude for producing images with different exposures, one light and one dark, is easily done. The question is whether this practice is unethical? It all depends. The scene is the same. I am not really adding or removing elements. I am just placing one exposure on top of another--darker on top of lighter.
Here's an example. Note that the final version is very sloppy, but with more care it could be a seamless transition between light and dark.
Composition 1
8th of a second at f/22
Composition 2
8th of second at f/8
Composite
I can see where ethics come into play here. It may be perceived that the manipulation actually alters the viewer's interpretation of the scene by controlling the exposures.Now if I were working for a news organization I would avoid controversy by simply using just one negative and then making the appropriate corrections in levels and not through layers. At the same time, if the picture were to be used in a gallery and represent a form of artistic expression then that would be just fine. The problem is that many younger photographers who have grown up manipulating images in Photoshop, might not understand the difference. In this way a digital dilemma occurs.