466:, which decreases the apparent flicker by painting first the odd lines and then the even lines (these are known as fields). This doubles the refresh rate, compared to a progressive scan image at the same frame rate. This works perfectly for video cameras, where each field results from a separate exposure – the effective frame rate doubles, there are now 50 rather than 25 exposures per second. The dynamics of a CRT are ideally suited to this approach, fast scenes will benefit from the 50 Hz refresh, the earlier field will have largely decayed away when the new field is written, and static images will benefit from improved resolution as both fields will be integrated by the eye. Modern CRT-based televisions may be made
373:, the effective refresh rate is halved, because each eye needs a separate picture. For this reason, it is usually recommended to use a display capable of at least 120 Hz, because divided in half this rate is again 60 Hz. Higher refresh rates result in greater image stability, for example 72 Hz non-stereo is 144 Hz stereo, and 90 Hz non-stereo is 180 Hz stereo. Most low-end computer graphics cards and monitors cannot handle these high refresh rates, especially at higher resolutions.
386:
36:
265:
451:(fps). For PAL 50 Hz this allows film sources to be easily transferred by accelerating the film by 4%. The resulting picture is therefore smooth, however, there is a small shift in the pitch of the audio. NTSC sets display both 24 fps and 25 fps material without any speed shifting by using a technique called
328:, set the default refresh rate to a conservative rate, usually 60 Hz. Some fullscreen applications, including many games, now allow the user to reconfigure the refresh rate before entering fullscreen mode, but most default to a conservative resolution and refresh rate and let you increase the settings in the options.
421:
was used for the vertical refresh rate for two reasons. The first reason was that the television's vacuum tube was susceptible to interference from the unit's power supply, including residual ripple. This could cause drifting horizontal bars (hum bars). Using the same frequency reduced this, and made
292:
On smaller CRT monitors (up to about 15 in or 38 cm), few people notice any discomfort between 60–72 Hz. On larger CRT monitors (17 in or 43 cm or larger), most people experience mild discomfort unless the refresh is set to 72 Hz or higher. A rate of 100 Hz is
513:
In the case of filmed material, as 120 is an even multiple of 24, it is possible to present a 24 fps sequence without judder on a well-designed 120 Hz display (i.e., so-called 5-5 pulldown). If the 120 Hz rate is produced by frame-doubling a 60 fps 3:2 pulldown signal, the uneven
509:
While common multisync CRT computer monitors have been capable of running at even multiples of 24 Hz since the early 1990s, recent "120 Hz" LCDs have been produced for the purpose of having smoother, more fluid motion, depending upon the source material, and any subsequent processing done
438:
color coding). This accident of chance gave
European sets higher resolution, in exchange for lower frame-rates. Compare System M (704 × 480 at 30i) and System B/G (704 × 576 at 25i). However, the lower refresh rate of 50 Hz introduces more flicker, so sets that use digital
223:
The refresh rate can be calculated from the horizontal scan rate by dividing the scanning frequency by the number of horizontal lines, plus some amount of time to allow for the beam to return to the top. By convention, this is a 1.05x multiplier. For instance, a monitor with a horizontal scanning
505:
The combination of content production, playback device, and display device processing may also give artifacts that are unnecessary. A display device producing a fixed 60 fps rate cannot display a 24 fps movie at an even, judder-free rate. Usually a 3:2 pulldown is used, giving a slight
255:
retain their state for as long as power is provided, and consequently there is no intrinsic flicker regardless of refresh rate. However, the refresh rate still determines the highest frame rate that can be displayed, and despite there being no actual blanking of the screen, the vertical blanking
376:
For LCD monitors the pixel brightness changes are much slower than CRT or plasma phosphors. Typically LCD pixel brightness changes are faster when voltage is applied than when voltage is removed, resulting in an asymmetric pixel response time. With 3D shutter glasses this can result in a blurry
268:
272:
271:
267:
266:
273:
239:, during which the beam is returning to the top right corner of the screen and no image is being drawn. Even in modern games, however, it is important to avoid altering the computer's video buffer except during the vertical retrace, to prevent flickering graphics or
270:
256:
interval is still a period in each refresh cycle when the screen is not being updated, during which the image data in the host system's frame buffer can be updated. Vsync options can eliminate screen tearing by rendering the whole image at the same time.
195:
297:, which is often locked at 60 fps. But this is rarely a problem, because the only part of an LCD monitor that could produce CRT-like flicker—its backlight—typically operates at around a minimum of 200 Hz.
501:
As movies are usually filmed at a rate of 24 frames per second, while television sets operate at different rates, some conversion is necessary. Different techniques exist to give the viewer an optimal experience.
446:
Another difference between 50 Hz and 60 Hz standards is the way motion pictures (film sources as opposed to video camera sources) are transferred or presented. 35 mm film is typically shot at 24
485:(3:2 pulldown). For PAL at 25 fps, 100 or 200 Hz is used as a fractional compromise of the least common multiple of 600 (24 × 25). These higher refresh rates are most effective from a
426:. Thus producers had little choice but to run sets at 60 Hz in America, and 50 Hz in Europe. These rates formed the basis for the sets used today: 60 Hz System M (almost always used with
174:, for instance, do not trace the entire screen, only the actual lines comprising the displayed image, so refresh speed may differ by the size and complexity of the image data. For computer programs or
208:
In a CRT, the vertical scan rate is the number of times per second that the electron beam returns to the upper left corner of the screen to begin drawing a new frame. It is controlled by the
269:
473:
Many high-end LCD televisions now have a 120 or 240 Hz (current and former NTSC countries) or 100 or 200 Hz (PAL/SECAM countries) refresh rate. The rate of 120 was chosen as the
543:
178:, the term is sometimes applied to how frequently a datum is updated with a new external value from another source (for example; a shared public spreadsheet or hardware feed).
422:
interference static on the screen and therefore less obtrusive. The second reason was that television studios would use AC lamps, filming at a different frequency would cause
235:
CRT refresh rates have historically been an important factor in video game programming. In early videogame systems, the only time available for computation was during the
335:
to a refresh rate higher than the highest rate supported by the monitor. Some models of monitors display a notice that the video signal uses an unsupported refresh rate.
524:"50 Hz" TV sets (when fed with "50 Hz" content) usually get a movie that is slightly faster than normal, avoiding any problems with uneven pulldown.
759:
159:, which describes how many images are stored or generated every second by the device driving the display. On CRT displays, higher refresh rates produce less
510:
to the signal. In the case of material shot on video, improvements in smoothness just from having a higher refresh rate may be barely noticeable.
293:
comfortable at almost any size. However, this does not apply to LCD monitors. The closest equivalent to a refresh rate on an LCD monitor is its
377:
smearing of the display and poor depth perception, due to the previous image frame not fading to black fast enough as the next frame is drawn.
205:
CRTs by their nature must refresh the screen since their phosphors will fade and the image will disappear quickly unless refreshed regularly.
349:
Some LCDs support adapting their refresh rate to the current frame rate delivered by the graphics card. Two technologies that allow this are
807:
623:
598:
735:
119:
538:
832:
186:
While all raster display devices have a characteristic refresh rate, the physical implementation differs between technologies.
856:
57:
725:
100:
53:
72:
440:
573:
79:
861:
236:
763:
86:
308:(First and Second Editions) set the refresh rate to the highest rate that they believe the display supports.
46:
282:
252:
164:
68:
474:
344:
785:
647:
518:
217:
517:
Additionally, material may be displayed with synthetically created smoothness with the addition of
414:
699:
731:
674:
448:
286:
209:
811:
633:
602:
463:
213:
160:
145:
385:
548:
456:
366:
93:
866:
533:
477:
of 24 fps (cinema) and 30 fps (NTSC TV), and allows for less distortion when
418:
240:
171:
152:
850:
836:
321:
553:
490:
467:
452:
313:
278:
666:
628:
439:
technology to double the refresh rate to 100 Hz are now very popular. (see
300:
Different operating systems set the default refresh rate differently. Microsoft
202:
167:, the refresh rate affects only how often the image can potentially be updated.
149:
35:
462:
Similar to some computer monitors and some DVDs, analog television systems use
521:
abilities to the display, which has an even larger effect on filmed material.
410:
370:
332:
317:
309:
305:
301:
294:
156:
678:
389:
This gif animation shows a rudimentary comparison of how motion varies with 4
325:
175:
194:
17:
577:
482:
423:
350:
251:
Unlike CRTs, where the image will fade unless refreshed, the pixels of
667:"Racing the Beam: How Atari 2600's Crazy Hardware Changed Game Design"
413:
in the 1930s was determined by a number of technical limitations. The
574:"How To Change the Screen Refresh Rate of Your Monitor in Windows XP"
455:, but at the expense of introducing unsmooth playback in the form of
354:
478:
435:
384:
263:
193:
430:
color coding) and 50 Hz System B/G (almost always used with
427:
170:
Non-raster displays may not have a characteristic refresh rate.
514:
motion could still be visible (i.e., so-called 6-4 pulldown).
486:
431:
29:
163:, thereby reducing eye strain. In other technologies such as
198:
Electron beam in the process of refreshing an image on a CRT
786:"Television broadcasting – video standards"
27:
Frequency at which a display hardware displays a new image
401:
Hz refresh rates. Entire sequence has a frame rate of 24
544:
List of smartphones with a high refresh rate display
216:, and is partially limited by the monitor's maximum
727:
The
Electrical Engineering Handbook, Second Edition
60:. Unsourced material may be challenged and removed.
833:"Six things you need to know about 120Hz LCD TVs"
148:(CRTs), is the number of times per second that a
144:in reference to terminology originating with the
331:Old monitors could be damaged if a user set the
155:displays a new image. This is independent from
8:
224:frequency of 96 kHz at a resolution of
120:Learn how and when to remove this message
565:
470:in the form of 100 Hz technology.
724:Dorf, Richard C. (26 September 1997).
599:"What is the Refresh Rate of Monitor"
481:are viewed due to the elimination of
7:
58:adding citations to reliable sources
312:-based operating systems, such as
25:
762:. soundscape.info. Archived from
493:), and/or scenes of fast motion.
539:Comparison of display technology
497:Displaying movie content on a TV
34:
808:"What is monitor refresh rate?"
760:"Lines, frames and frequencies"
45:needs additional citations for
700:"What is Monitor Refresh Rate"
1:
648:"XFree86-Video-Timings-HOWTO"
228:results in a refresh rate of
665:Kohler, Chris (2009-03-13).
441:Broadcast television systems
281:rotating at 0, 300 and 1300
489:-source video output (e.g.
232:89 Hz (rounded down).
883:
342:
237:vertical blanking interval
230:96,000 ÷ (1024 × 1.05) ≈
212:signal generated by the
636:July 1993. p. 177.
253:liquid-crystal displays
247:Liquid-crystal displays
165:liquid-crystal displays
406:
289:
283:revolutions per minute
199:
857:Television technology
624:"The Perfect Display"
475:least common multiple
388:
345:Variable refresh rate
276:
197:
138:vertical refresh rate
519:motion interpolation
369:are used for stereo
339:Dynamic refresh rate
316:and its descendants
218:horizontal scan rate
54:improve this article
409:The development of
788:. tvradioworld.com
758:Emmerson, Andrew.
407:
290:
200:
142:vertical scan rate
862:Graphics hardware
506:uneven movement.
449:frames per second
287:frames per second
285:, recorded at 60
274:
260:Computer displays
210:vertical blanking
190:Cathode-ray tubes
146:cathode-ray tubes
130:
129:
122:
104:
16:(Redirected from
874:
841:
840:
835:. Archived from
829:
823:
822:
820:
819:
810:. Archived from
804:
798:
797:
795:
793:
782:
776:
775:
773:
771:
755:
749:
748:
746:
744:
730:. p. 1538.
721:
715:
714:
712:
710:
695:
689:
688:
686:
685:
662:
656:
655:
644:
638:
637:
634:Ziff Davis, Inc.
620:
614:
613:
611:
610:
601:. Archived from
595:
589:
588:
586:
585:
576:. Archived from
570:
404:
400:
396:
392:
275:
231:
227:
214:video controller
182:Physical factors
136:, also known as
125:
118:
114:
111:
105:
103:
62:
38:
30:
21:
882:
881:
877:
876:
875:
873:
872:
871:
847:
846:
845:
844:
831:
830:
826:
817:
815:
806:
805:
801:
791:
789:
784:
783:
779:
769:
767:
766:on 23 July 2006
757:
756:
752:
742:
740:
738:
723:
722:
718:
708:
706:
697:
696:
692:
683:
681:
664:
663:
659:
646:
645:
641:
622:
621:
617:
608:
606:
597:
596:
592:
583:
581:
572:
571:
567:
562:
549:High frame rate
530:
499:
457:telecine judder
402:
398:
394:
390:
383:
367:shutter glasses
363:
361:Stereo displays
347:
341:
264:
262:
249:
229:
225:
192:
184:
172:Vector displays
126:
115:
109:
106:
63:
61:
51:
39:
28:
23:
22:
15:
12:
11:
5:
880:
878:
870:
869:
864:
859:
849:
848:
843:
842:
839:on 2007-10-28.
824:
799:
777:
750:
736:
716:
690:
657:
639:
615:
590:
564:
563:
561:
558:
557:
556:
551:
546:
541:
536:
534:Plasma display
529:
526:
498:
495:
419:line frequency
382:
379:
362:
359:
340:
337:
261:
258:
248:
245:
241:screen tearing
191:
188:
183:
180:
153:display device
128:
127:
69:"Refresh rate"
42:
40:
33:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
879:
868:
865:
863:
860:
858:
855:
854:
852:
838:
834:
828:
825:
814:on 2021-01-08
813:
809:
803:
800:
787:
781:
778:
765:
761:
754:
751:
739:
737:9781420049763
733:
729:
728:
720:
717:
705:
701:
694:
691:
680:
676:
672:
668:
661:
658:
653:
649:
643:
640:
635:
631:
630:
625:
619:
616:
605:on 2021-01-08
604:
600:
594:
591:
580:on 2015-02-22
579:
575:
569:
566:
559:
555:
552:
550:
547:
545:
542:
540:
537:
535:
532:
531:
527:
525:
522:
520:
515:
511:
507:
503:
496:
494:
492:
488:
484:
480:
476:
471:
469:
465:
460:
458:
454:
450:
444:
442:
437:
433:
429:
425:
420:
416:
412:
387:
380:
378:
374:
372:
368:
360:
358:
356:
352:
346:
338:
336:
334:
329:
327:
323:
322:Windows Vista
319:
315:
311:
307:
303:
298:
296:
288:
284:
280:
277:A video of a
259:
257:
254:
246:
244:
242:
238:
233:
221:
219:
215:
211:
206:
204:
196:
189:
187:
181:
179:
177:
173:
168:
166:
162:
158:
154:
151:
147:
143:
139:
135:
124:
121:
113:
102:
99:
95:
92:
88:
85:
81:
78:
74:
71: –
70:
66:
65:Find sources:
59:
55:
49:
48:
43:This article
41:
37:
32:
31:
19:
837:the original
827:
816:. Retrieved
812:the original
802:
790:. Retrieved
780:
768:. Retrieved
764:the original
753:
741:. Retrieved
726:
719:
707:. Retrieved
704:Tech Gearoid
703:
698:Qazi, Atif.
693:
682:. Retrieved
670:
660:
651:
642:
627:
618:
607:. Retrieved
603:the original
593:
582:. Retrieved
578:the original
568:
554:Flicker-free
523:
516:
512:
508:
504:
500:
491:Blu-ray Disc
472:
468:flicker-free
461:
453:3:2 pulldown
445:
408:
375:
364:
348:
330:
314:Windows 2000
299:
291:
250:
234:
222:
207:
201:
185:
169:
150:raster-based
141:
137:
134:refresh rate
133:
131:
116:
107:
97:
90:
83:
76:
64:
52:Please help
47:verification
44:
629:PC Magazine
411:televisions
381:Televisions
371:3D displays
226:1280 × 1024
203:Raster-scan
851:Categories
818:2020-12-18
684:2020-08-16
609:2020-12-18
584:2007-10-19
560:References
397:Hz, and 24
343:See also:
333:video card
318:Windows XP
310:Windows NT
306:Windows 98
302:Windows 95
295:frame rate
161:flickering
157:frame rate
110:April 2008
80:newspapers
18:Field rate
679:1059-1028
464:interlace
365:When LCD
326:Windows 7
176:telemetry
528:See also
483:telecine
424:strobing
351:FreeSync
792:25 June
770:25 June
743:25 June
709:May 15,
279:CPU fan
94:scholar
734:
677:
479:movies
417:power
403:
399:
395:
393:Hz, 12
391:
355:G-Sync
96:
89:
82:
75:
67:
867:Rates
671:Wired
436:SECAM
101:JSTOR
87:books
794:2015
772:2015
745:2015
732:ISBN
711:2019
675:ISSN
652:TLDP
428:NTSC
353:and
324:and
304:and
132:The
73:news
487:24p
434:or
432:PAL
405:Hz.
140:or
56:by
853::
702:.
673:.
669:.
650:.
632:.
626:.
459:.
443:)
415:AC
357:.
320:,
243:.
220:.
821:.
796:.
774:.
747:.
713:.
687:.
654:.
612:.
587:.
123:)
117:(
112:)
108:(
98:·
91:·
84:·
77:·
50:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
