Digital BW, The Print

On Windows XP and using CS3, I print toned monochromes on an Epson 
2400. Both monitor and printer/paper combination are calibrated. I use 
an LCD monitor, and the printer output when viewed under a bright 
white bulb corresponds well to the appearance on the monitor. However 
in lower viewing light levels as, say, a camera club venue, shadow 
details are more difficult to discern. This more of a problem with 
images that are printed more darkly, which, in my case, is quite a 
high proportion.
I have tried applying a brightening levels adjustment, but, having 
worked hard to produce subtle shadow detail, I feel this is a very 
blunt tool for solving my problem.
Have others experienced this problem? If so, how have you approached 
the problem?
Many thanks
John