My uncertainty is where does the eye/brain start to fail to compensate and what to do then? I'm thinking about prints destined for the dim restaurant walls, and longe rooms lit by a couple of shaded lamps. Do you then reach for a curves compensation to lighten the print (or even Matt's maligned slider in LR)?
How is it the daily comics can be read and spotted from across the room even when it's printed on the dullest paper stock in existence and viewed under living room to subway light? It's because the rendering is black ink on white paper which doesn't mean the image was made to look brighter but more contrasty.
Composition and the placement of darks and lights also attracts and communicates ideas. Cartoonist Milton Caniff's "Terry and the Pirates" and "Steve Canyon" demonstrates a masterful example of how composition (placement of blacks and whites) can grab the eye with just black ink on paper no matter the lighting conditions and the paper it's printed on.
For instance I wouldn't want to display in a dimly lit restaurant a print depicting a deer standing far away in a deep dark forest as a way to communicate the serenity of nature. I'ld display a close up of a deer foraging in a brightly lit field of pale green sawgrass.
It's the appearance of contrast that gives the impression of brightness and that's determined by image content as Andrew pointed out.
As another example, what's being communicated in the following linked image?...
The child's emotional state, right?...
http://www.animationresources.org/pics/caniffteaser2.jpgIt's meant to look dark with all that black ink but the idea is simply related by the use of composition even when it's this small viewed on the web.
Most amateur photographers don't think like this especially when all they want is to just take a picture and hang it on a wall.
Another one that's meant to look dark...
http://madinkbeard.com/blog/wp-content/images/caniff2.gif
