> visual perception

I dunno.  Isn't the usual manifestation that multiplexed and/or  
charlieplexed LED displays don't seem nearly as dim as they ought to  
be, given their actual on-time.  I've seen 3 or 4 digit displays and  
done 20-led dot-matricies that light one segment or LED at a time, and  
they certainly don't look ~1/20th the of the "normal rated current"  
brightness of the individual LEDs...

BillW

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist