From: into@oblivion.nothing.com   
      
   Phil Hobbs  wrote in   
   news:53342CF7.8050407@electrooptical.net:   
      
   > Yup.  The emission lines respond faster than the phosphor.  Near the   
   > ends of the tube, electronic ballast tubes have emission lines modulated   
   > by up to the ~50th harmonic of the 40 kHz drive frequency.   
      
   You can even see this modulation, this shift in color, by   
   twiddling a shiny object really fast with your fingers, such   
   as a pen. The light reflection shows as alternating bands   
   of bluer and yellower light.   
      
   Heck, I even can see it from the light of my LCD monitor. I   
   sometimes notice it on the screen itself under the right   
   circumstances, such as a white bar or line on a black screen   
   as I flick my eyes around on the screen.   
      
   As an aside, I seem to be in that 10% category of the population   
   who can detect higher refresh rates that normal. Back in the   
   CRT days even 85 hz monitors flickered to me. Vehicle LED tail   
   lights that are pulsed are very distracting to me. As I drive   
   and am scanning the road, the tail lights break into a string   
   of dots. Another example is seeing the color banding on the   
   older color wheel type movie projectors.   
      
   Brian   
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