My own metric has always been "something that looks like what I saw through the viewfinder at the time I took the photo".
The problem with this metric is that it is very easy to make something that looks nothing like what you saw through the viewfinder with only simple adjustments such as exposure time and printing contrast. And what about alternative process printing, that can, in some cases, render a negative into something completely unreal and unlike what was seen through the viewfinder.
I think it's very difficult to find any metric that will mean something consistently.
Jeff Spirer
Photos: http://www.spirer.com
One People: http://www.onepeople.com/
Surfaces and Marks: http://www.withoutgrass.com
