I suspect my monitor is getting darker. I have a SyncMaster 214T and cannot get it bright enough for medium ambient light settings when I calibrate with a Spyder3. I have dimmed the ambient light (a full spectrum lightbulb) in my room to low level light to compensate for this, but I want to know if my monitor is still good enough. According to the calibration software (Spyder 3 elite) it is, but how do I know for sure?