monitor dim timing

I don't really see the purpose of a half-sleep mode; I mean, if I wanted the monitor to dim after 90 seconds
dyehANTISPAM wrote on :

Hi-- sorry for the series of posts, I've just been gathering up questions and decided to ask them all at once. First:

I have an iMac G5. I have my screen sleep setting to 3 minutes. Halfway through this if there is no keybaord/mouse activity (and it seems to be at the halfway point of whatever the sleep setting is), the monitor dims about 50%. Now, this is a little annoying since it's often while I'm reading a long document, and it could easily take me 90 seconds to read a long passage without needing to move the mouse. Then I have to reach for and jiggle the mouse to get it to wake up again. I'm guessing that this is standard unmodifiable OS X behavior and my only solution is to increase the sleep time, but I wanted to check if anyone had a solution. I don't really see the purpose of a half-sleep mode; I mean, if I wanted the monitor to dim after 90 seconds, I would set the sleep time to 90 seconds.

thanks, dave