When shooting HD 23.98fps, audio recorded separately (if not on the camera) is 48k at 29.97fps, because there is never a change in reference (59.94Hz). 29.97fps pulled from 23.98 has duplicate fields, whereas 23.98fps does not. This 23.98fps can either be left alone and played on HD monitors or computer monitors, or pulled down to 29.97fps, and played on any monitor – the pulldown only changes the frame count, not the speed. 1% to simulate the effect of changing reference from 60hz to 59.94hz, to arrive at 23.98. If the camera shoots a true 24fps just like film, it must be slowed by. Now, if an HD video camera wants the “film look”, they shoot 24P (which, unless it’s the Varicam or the like) is 23.98, and no speed adjustment is necessary before pulldown. But, this allows Film to be displayed on a standard NTSC monitor. There are duplicate fields when this happens. Thereby fitting 23.98 progressive film frames on 29.97 interlaced video frames. 1% slowdown due to reference change, Film is generally pulled down via the 2:3:2 method which maps the first film frame to 2 fields of video, the next frame of film to 3 fields of video, and so on. HD video is often done this way as HD monitors can display 23.98fps, though I read film is usually edited in 29.97fps. Now, 23.976fps (aka 23.98fps) can be edited on a 23.98fps timeline with 23.98 timecode in Final Cut Pro, and edited in Pro Tools with a 23.98 session Time Code rate. 1% slowdown comes from, NOT from a 2:3:2 pulldown. This change in reference of time (60Hz verses 59.94Hz) is where the. X = 23.976 (This is where the 23.98 number comes from) To allow film to be played at this rate, first it must be referenced to video time instead of film time (NONE of my books described it in this way) Now, most video monitors will only display 29.97fps. So, the new reference for NTSC is 59.94 HZ – This is the length of one second for NTSC, as well as the amount of fields per second. NTSC color video was changed to 29.97fps, so there must be a new reference.ģ0fps / 60hz = 29.97fps / X (solve for X) Since it’s interlaced, each frame is composed of 2 fields, for a total of 60 fields. Originally, black and white video was 30fps, referenced to 60Hz. Now I believe I do, it's all about the time reference! So, here's my entire explanation, compiled from various books and my own figurin':įilm speed is 60Hz – That is the length of one second for Film.įilm is shot at 24fps referenced to 60Hz. I've read all the posts here, and the chapters dealing with timecode over and over and could not get it. And if they do, I have yet to comprehend it. NONE have completely described why 23.98 lines up with 29.97, and the methodology behind it. Let me start this by saying I have Pro Tools for video, film, and multimedia / Dialog Editing for Motion Pictures / Sound for Digital Video, and many other books.
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