 These monitors ran at higher scanning frequencies, typically allowing a 75 to 90 Hz field rate (i.e.37 to 45Hz frame rate), and tended to use longer-persistence phosphors in their CRTs, all of which was intended to alleviate flicker and shimmer problems.Such monitors proved generally unpopular, outside of specialist ultra-high-resolution applications such as CAD and DTP which demanded as many pixels as possible, with interlace being a necessary evil and better than trying to use the progressive-scan equivalents.