i think you are reffering to illuminating guages and backlit guages.
non-illuminating guages would have no lighting source meaning you would not be able to see them at night.
backlit guages have a solid face that is recessed from the housing. the light output comes from aroung the the guage face illuminating it. a perfect example would be autometer' s sport comp and ultralite series'
illuminating guages allow for the light output to come from the actual number digits and hash markings themselves. example: hks black-faced guages
I think they are askin about the EL to the normal gauges.
The electruluminesent(spelling?) lights up red all the time during he day they are lit and when the car is off they go fully black.
The normal gauges do not light unless the lights of the vehicle are turned on and when they do light look just like the EL gauges when you turn them off you still see all the numbers and everything
The non-EL (electroluminescent - close ) gauges are NOT as bright as the EL ones at night, but merely similar. A trained eye can detect the difference in an instant.
I wish I had EL (2003 - not without Sport, 2004, all V6 have it), because it looks way nicer in the day - but (IMO) is too bright at night (even the 2/3 settings available). The (bulb) illuminated non-EL gauge has the typical dimmer allowing you to tone down the light levels substantially.
Photos - check image forums such as cardomain.com and images on mazda6club.com galleries - there' bound to be a few!
Yeah, the EL is only too bright at night if you set it that way. Mine is set to dim right down when you turn the lights on. This includes the gauge display and the area that shows your temp controls and stereo info. It isn't any brighter at night then the non EL display in my opinion.