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fps for HD???


fatfatjames

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ok another tricky problem... we shoot HD in pal world but edit in NTSC world... what FPS should i follow? pal world's fps or ntsc's fps?

Is your sound going to be synched to picture before or after the PAL to NTSC transfer?  If before, use 25 FPS.  If after, use 29.97 FPS. 

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Guest Eric Lamontagne

FatFatJames

Which audio is going to be the master audio? HD or DAT? If DAT is the master, does this mean an audio conform will occur for dailies and or post editorial/post sound?

HD rolls at 23.976 when trying to emulate film, not 24fps. This is to make it mathematically compatible with NTSC 29.97fps.

If it was me, and I do it daily this way, I would offer my client the easiesy (and least costly) method. This for me in your case it would be using the higher bit rate of the HD cameras to provide a hardwired (and closely monitored) audio feed to each camera. DAT is 16bit and HD is 20bit (Sony). This saves thousands later in post and will make you a producer's friend if done correctly. DAT would be the backup.

In the HD world, cables on cameras are just part of the job.

Find out what framerate post audio will be working with the audio in. Make sure you match this with your DAT and timecode slates (make sure you HEAR the clapper sticks). Slates are NOT redundant even if the only audio is on the HD cam! If rolling an additional recorder like a DAT, Provide a time of day timecode (hopefully a lockit box) to every camera that has the same time of day timecode as the slates and your recorder. If you are shooting compatible framerates (IE DAT and HD running both at 25fps - or - DAT at 29.97ndf and HD at 23.976) then jam the timecode input of the HD cameras with the lockit box. If framerates are incompatible (IE DAT at 29.97ndf and HD at 25fps) then put a mono audio mix of channel 1 of HD audio and your timecode (29.97ndf) audio channel 2 of HD camera for later use.

Timecode jam every 4-6 hours depending on conditions. It's handy to have a GR-1, Anbient 301 slate or Ambient master clock for timecode comparison.

Happy shooting!

Eric Lamontagne

eric#at#acmesound#dot#net (remove the # and add @ and .)

PS. Wolf Seeburg makes excelent reading material for this and many other questions! "Sound for 24p by Wolf Seeburg"

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FatFatJames

Which audio is going to be the master audio? HD or DAT? If DAT is the master, does this mean an audio conform will occur for dailies and or post editorial/post sound?

HD rolls at 23.976 when trying to emulate film, not 24fps. This is to make it mathematically compatible with NTSC 29.97fps.

If it was me, and I do it daily this way, I would offer my client the easiesy (and least costly) method. This for me in your case it would be using the higher bit rate of the HD cameras to provide a hardwired (and closely monitored) audio feed to each camera. DAT is 16bit and HD is 20bit (Sony). This saves thousands later in post and will make you a producer's friend if done correctly. DAT would be the backup.

In the HD world, cables on cameras are just part of the job.

Find out what framerate post audio will be working with the audio in. Make sure you match this with your DAT and timecode slates (make sure you HEAR the clapper sticks). Slates are NOT redundant even if the only audio is on the HD cam! If rolling an additional recorder like a DAT, Provide a time of day timecode (hopefully a lockit box) to every camera that has the same time of day timecode as the slates and your recorder. If you are shooting compatible framerates (IE DAT and HD running both at 25fps - or - DAT at 29.97ndf and HD at 23.976) then jam the timecode input of the HD cameras with the lockit box. If framerates are incompatible (IE DAT at 29.97ndf and HD at 25fps) then put a mono audio mix of channel 1 of HD audio and your timecode (29.97ndf) audio channel 2 of HD camera for later use.

Timecode jam every 4-6 hours depending on conditions. It's handy to have a GR-1, Anbient 301 slate or Ambient master clock for timecode comparison.

Happy shooting!

Eric Lamontagne

eric#at#acmesound#dot#net (remove the # and add @ and .)

PS. Wolf Seeburg makes excelent reading material for this and many other questions! "Sound for 24p by Wolf Seeburg"

cool thanx... very informative... need to get as much information as i can get before i switchover to 744 end of the year...

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  • 3 weeks later...
Guest midas

Hi guys i am from the pal world... If i am doing a double system on a DAT recorder, what film rate should i set to? The camera is a HD camera... Shouold i still record at 25 FPS or 29.97NDF?

James,

Nice to see you here, first check what frame rate are they shooting, talk to the camera crew, video editor and audio post.

Most likely in Singapore they are shooting 25fps, true 24fps i think only comes with the FW900 Sony camera. So another question for them is what camera are they shooting??

If its a local production, they will likely ended up shooting 25 as the editor will tell them so (I came across once). Transfer will be 25fps D5 to filmout.

If post will transfer Pal to NTSC that will be 23.976. I just finish a post audio job with all the D5 in NTSC but its original were from PAL source. All the audio will be at 23.976 with pull down. Although i still prefer 29.97, well thats another story.

If your are sure everything is 24fps or rather its really 23.976 then that will be straight forward, its either 29.97NDF or 23.976NDF @ 48K/0.01% pull down (correct me if i'm wrong anyone), all these also depend on the workflow, but thats my workflow. Seriously I don't see why they wanna shoot 23.976 here, the refresh rate is 59.94Hz the DP will have some headache.

The sound that I supervised, on 1 short film recently, shot on varicam, I work out the workflow for them, eveything on 25 and final mix on 25, audio layback to D5 @25fps. D5 to filmout @ DFG Canada.

Workout the workflow before u shoot James, talk to all the people from production to post. When you port over to SD744T, you will have to workout with them again, but this time its the post world, you can record all the iso mic you want but the editor will not be comfortable to edit in multitracks and only track 1-2 will be use on the cutting table, Thats your boom and mix lavs. Call the whole world and tell them that u are recording on multitracks so they will look into it or else its just a waste of time.

But still a good 2 tracks mix is still the most important.

Alan Chong

Midas Production Sound Singapore

PS. Blk 22 don't work out well in Singapore, take a Blk22 Lectro and do a scan and you will know what I mean, especially in town area.

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Guest midas

it is going to sync before... but the audio post going to be done in NTSC world

James,

Edit in NTSC world doesn't mean it has to be really NTSC, Avid Adrenaline does all world. Only house reference will be the problem, so check it out too.

Sync before? If its shot in 25fps then everything will be 25fps, sound post can toggle between NTSC and PAL now adays easily. Still check with them.

I think all of the advice here were very good ranging from frame rates to tri level sync. Try your best to send some guide tracks to the camera and try your best to stop video post from using your guide tracks :) Sad but it happens.

Alan

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  • 4 months later...

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