Is fluorescent lighting a significant source of flicker?
(From: Bob Myers (myers@fc.hp.com)). Actually, this is a myth. Ambient light flicker is at best a second-order effect in determining perceived flicker levels, and then only through modulating the display’s contrast ratio. (Ambient light flicker isn’t even considered in the flicker calculations of the various ergonomic standards, although the ambient light *level* is a concern.) The notion that fluorescent lamps flicker and that this somehow produces a “beat” with the screen refresh is simple to disprove. First, if this were so, 75 Hz screen refresh would appear WORSE than 60 Hz, since it’s farther removed from the line rate. In reality, the reverse is true – and if you REALLY want to maximize perceived flicker, turn OFF all the lights. The display will then appear to flicker MUCH worse, as one determining factor in flicker is the APPARENT brightness of the screen (how bright the screen is in relation to its surroundings). Lastly, people don’t realize that fluorescents DON’T flicker at
(From: Bob Myers (myers@fc.hp.com).) Actually, this is a myth. Ambient light flicker is at best a second-order effect in determining perceived flicker levels, and then only through modulating the display’s contrast ratio. (Ambient light flicker isn’t even considered in the flicker calculations of the various ergonomic standards, although the ambient light *level* is a concern.) The notion that fluorescent lamps flicker and that this somehow produces a “beat” with the screen refresh is simple to disprove. First, if this were so, 75 Hz screen refresh would appear WORSE than 60 Hz, since it’s farther removed from the line rate. In reality, the reverse is true – and if you REALLY want to maximize perceived flicker, turn OFF all the lights. The display will then appear to flicker MUCH worse, as one determining factor in flicker is the APPARENT brightness of the screen (how bright the screen is in relation to its surroundings). Lastly, people don’t realize that fluorescents DON’T flicker at
