For 24 fps Feature Film productions, it is recommended that original sound should be shot using 25 fps Timecode if the sound postproduction is to be carried out in the UK or Europe, or 30 fps non-drop frame Timecode if the sound post-production is to be done in the US. There may be occasions where some postproduction is carried out in the UK and later in the US. It is recommended that 30 fps non-drop frame Timecode is used for this purpose and that the non-linear post-production should be carried out from NTSC video transfers in the UK. This presents no problems for Avid/Lightworks editors but it will mean NTSC videotapes and viewing equipment for the production. It was also agreed that the use of 24 fps Timecode on original sound recording should be actively discouraged because it does not work with the PAL or NTSC video systems, nor should 29.97 or 30 fps drop frame be employed for film making. If required, the drop frame time correction can be done at a later stage for Television Broadcast. It is not relevant to Film and Sound Editing. Another problem discussed was the technique of shooting at non-standard film speeds for special effects and action. It is possible to adjust the speed of sound to match with or without changing the pitch and thus synchronise the sound to the non-standard picture rate by using an audio workstation and suitable software. The point was made that this should be done before the syncing up process so that the resulting database is correct. A common requirement is shooting television or simulated computer screens where 25 fps PAL videotape material is used and the film camera is then switched from 24 fps to 25 fps to avoid roll bars. This material should be very carefully logged in both picture and sound reports, particularly if using the 'phantom frame' method of video transfer for the 24 fps material. It frequently goes wrong at the negative cutting stage if the editor doesn't have the correct information. Also discussed was that if direct negative transfer to video is employed, together with syncing up 'on the fly' in Telecine, the risk of negative damage is greatly increased due to the Telecine operator having to stop and shuttle the picture to find the sync marks. This practice should be discouraged. Only a single pass, non-stop negative transfer to video is recommended and if sound has to be synced up by Telecine, it should be done to the videotape as a second process. However, the goal posts are constantly moving as technology races on. What was a problem last year very quickly becomes a solution this year! I am sure there are many who have the solution to the problem. Let us hear from you and add to | the debate. Email me at info@amps.net or write to the Newsletter Editor. If you are on the Internet, a good web site to visit is www.videosonics.com for a further information on the various 24/25 frame post-production routes. In conclusion, it was decided to issue the following guide lines for Production Mixers for shooting Film at 24 fps: |
