One of the problems with judging an image on the monitor is that most monitors are set too bright. This is especially critical if you want to print the image based on what you see on the monitor. When the monitor is too bright, it makes the images look brighter and more contrasty then they really are. When printed, these images viewed on an overly bright monitor tend to look dark or dull and washed out. To fix this (calibrate your monitor using a professional calibration device ) or if thats not an option due to cost, then set the brightness of your monitor as per the following instructions:
Display the link below on your monitor and adjust the brightness of the monitor until you can view all of the different brightness levels on the second row. You should adjust the monitor brightness (probably turning it down) until you can see differences in each box (especially the 100 box and 95, as well as the 5 and 0) Both ends of the brightness scale must be visible at the same time.
Also check the second from the bottom row (white scale from 15% grey to totally white) and the bottom row (100% black to 85% black). These rows can assist with fine tuning. Unless you have a professional quality monitor, you will not be able to see differences in the 100-95 range.
View brightness chart: Brightness.tif
Some older monitors may require contrast to be adjusted as well.