Graeme Nattress
Forum Replies Created
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“What kind of result do I get if I cut a 23.98 clip into a 29.97 timeline?”
A poor one. You also get a discontinuity in feel as the 29.97 clips look like video, and if you just use FCP to convert the 23.98fps to 29.97fps, you’ll get a jumpy jerky effect on those clips too.
“I have to render it, but the speed doesn’t seem to change at all. Is it just adding 3:2 pulldown?”
No it isn’t. It adds in padding frames. Because it’s not field based, it’s not 3:2 pulldown and it’s not smooth. Try it and see for yourself. Set your canvas to 100%, view as square pixels turned off, and step through frame by frame.
“If so, how is that different from what G Film Converter does? Is there a different algorithm applied? If I want just plain old 3:2 pulldown added to my 23.98 clips, can I just use FCP for that?”
FCP doesn’t add 3:2 pulldown, but does a really poor job of the conversion of frame rates – hence the Standards Converter got written.
“Also, when working in a 23.98 timeline, you said that FCP will add pulldown on output via firewire. But will it also add pulldown when not going to a DV deck/converter? I ask because I use an AJA Io sometimes.”
Only DV over firewire, not IO over firewire. One of the reasons that the converter was written was for people wanting to send 24p back out over, say, digibeta, for which FCP didn’t provide and option.
Graeme
– http://www.nattress.com – Film Effects for FCP
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“If I capture pro50 via firewire and then master via component to betasp, I want to make sure my D/A box is ADDING 7.5. ”
YES!
“However, if I am capturing BetaSP footage to fcp via IO and then mastering back to Beta, I want to make sure it is not adding or subtracting”
NO. The IO should be set to remove setup on input so that the blacks in FCP are at code 16 which is 0%, and the IO should add setup on output so that those blacks go to 7.5IRE on analogue tape. In FCP blacks should always be at code 16 or 0% on the FCP scopes. That’s because FCP is designed to to work correctly this way – just think of it as non-linear digital video tape, and think of dubbing Analogue to digital and then back to analogue.
“And if I am recording from betasp to Pro50 deck via component I want to Sub 7.5 on my Pro50 deck?”
YES!
“And FCP just keeps the IRE level as whatever it was brought in as? so if I come into FCP via I/O BetaSP, my program will be at 7.5, but if I come in firewire off pro50 my project will be 0. Ow, my head is beginning to hurt.”
FCP will, but FCP does not deal with IRE, but with digital video. IRE gets added or subtracted by the DtoA and AtoD converters in the IO.
Whenever you go from analogue to digital, you must make sure that your blacks end up at code 16 or 0% on the FCP scopes. To do this, you have to set the AtoD converter to correctly remove setup if present. Similarly on going from DtoA, you have to tell the converter to add setup if necessary.
“Okay and for a broadcast overview question…if a tv station were working entirely in dvcpro (which some are) through the entire chain, when would the 7.5 be added (isn’t 7.5 the required broadcast standard)?”
7.5IRE is the broadcast standard in North America only. If you submit a digital tape, then it’s not analogue and hence there is no IRE at all. Only when that tape gets converted to analogue, does setup get added if appropriate, and this will happen somewhere in the broadcast chain. If they are broadcasting digitally, it might even get added in the viewer’s home in their digibox.
Graeme
– http://www.nattress.com – Film Effects for FCP
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Even uncompressed HDCAM is hard to key – best bet is to capture uncompressed 4:2:2 HD over HD SDI direct off the camera head itself and key from that.
The other thing to do, is if you’re just ending up with SD, is to key with your HDV as best as you can, and when you reduce it’s size to SD, that should make things look a lot better, or indeed, in AE, downsample your HDV to SD size and then key – either way it should work good. But to key HDV and leave it at HD rez is probably a recipe for disaster.
Graeme
– http://www.nattress.com – Film Effects for FCP
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Yes. That’s right, and it’s something you’ve got to be careful of when you begin mixing analogue and digital video.
Graeme
– http://www.nattress.com – Film Effects for FCP
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There’s a setting on the IO control panel that will add 7.5IRE setup to the analogue outputs. You should make sure that that setting is set correctly. I’d also, if you’re keeping a personal master, do a DVCpro50 master too to preserve the quality of your project, should you need to go back to the master and recapture as DVCpro50 is a very much higher quality format than BetaSP.
Graeme
– http://www.nattress.com – Film Effects for FCP
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Digital video has no setup, and 8bit digital video works on a scale called REC601 which has black at code 16 and white at code 235, which FCP represents as 0% to 100%.
IRE is a strictly analogue phenonema. You have to worry about it if you convert analogue video to digital or digital video to analogue. You also have to worry about it in certain cameras, specifically DV cameras which don’t add setup correctly on the analogue outputs but fake it by recording black at code 32 on the digital scale, which produces “incompatible” DV tapes that need to be corrected in post.
What devices are you using to being in your analogue video or output analogue video. The control panel for that device will allow you to set the correct value of setup, 0IRE or 7.5IRE depending on your source or destination.
Capturing DVCpro50 over firewire is a digital transfer, so FCP just keeps the levels whatever they are on tape, which should leave black at 0% (code 16) and white at 100% (code 235). If you’re using the DVCpro50 deck as an analogue to digital converter for bringing in BetaSP into your system, you should set the menus to deal with the setup correctly on the analogue inputs and outputs.
Graeme
– http://www.nattress.com – Film Effects for FCP
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But conform is not useful in this scenario as it will speed up the 24p to make it run at 29.97 putting a massive pitch shift on the audio and making the action run fast! The correct way to convert 24p to 29.97 for using 24p in a 29.97 timeline is to add 3:2 pulldown which is a feature that Cinema Tools (or FCP for that matter) does not have. FCP will only add 3:2 pulldown on play out over firewire, which makes it quite useless for many workflows.
Graeme
– http://www.nattress.com – Film Effects for FCP
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If you’re editing on a 23.98fps timeline, which is the best way to edit 24pA footage, then none of the clips will have pulldown in them, as they will have had their pulldown removed. 29.97fps footage (60i) is video, and has no 3:2 pulldown, so you must do a 60i to 24p conversion to make it look like it was shot at 24p originally.
If you were to go the other way and add pulldown to your 24p footage and edit in a normal NTSC 29.97fp timeline you would get video look and film look all mixed together, and unless that is the intention, that some shots look like video and some like film, it will look like a mess and the different shots would have different ‘feels’ about them – ie not homogenous.
There a little demo move here – NTSC to 24p: https://www.nattress.com/standardsConversionMovie.htm
that show how it works, and if you want to see the results: https://www.nattress.com/filmEffectsMovies.htm and https://www.nattress.com/BirdBrains/birdBrainsMovie.htm were both converted from 60i to 24p with the converter.Hope that helps,
Graeme
– http://www.nattress.com – Film Effects for FCP
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I’ve never seen a “add 3:2 pulldown” option in Cinema Tools! Can you tell me where to find it as I’d never gone to all the bother of writing my own 3:2 pulldown adder if there was one already in the software. I can’t see any reference to addition of 3:2 pulldown in the manual, but that manual is woefully innacruate.
Graeme
– http://www.nattress.com – Film Effects for FCP
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Check out my Standards Converter at http://www.nattress.com
It will either convert 29.97 to 23.98 for you, or add 3:2 pulldown to your 23.98fps material, or even convert 24pA to 24p normal for editing in a 29.97fps timeline.
However, for the most homogenous look between footage types, I’d convert the 29.97fps to 23.98fps and edit everything on a 23.98fps timeline.
Graeme
– http://www.nattress.com – Film Effects for FCP