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PAL film problems....25 to 24 conformPosted by RichSmither
Hi guys
Hoping someone can help me with a technical question.. Am using FCP 5.11with Kona card to edit a PAL film. We've shot on 35mm 3-perf and are having rushes delivered as 25fps synched DVCAM tapes. Once I've digitised the tapes I've done a 25 to 24 conform and then rendered my clips. The problem is that when I watch the rushes back on my viewing monitor there is a very strong frame flutter every second. It makes the footage unwatchable. Another problem is that my sequence monitor picture is now out of synch with the audio. Am I making a simple mistake that anyone can recognise? Thanks Rich
Not sure why you're doing the workflow that way because basically there's no way to monitor 24 fps material on a video monitor!
What you're seeing is Final Cut Pro trying to keep your 24fps footage in sync with your 25fps television system/monitor. I'd expect a frame duplication every second to keep in sync since there is no provision for 24 on 25 in the PAL system. (In NTSC 24 fps material gets pulldown to match with 29.97 video, in PAL 24 fps film is simply played at 25 frames, as I'm sure you know.) Normal workflow would have been to keep in 25 fps throughout the edit until picture lock. Then do the 25 to 24 fps conform (presumably for film out, as that's the only reason you'd do that). You must also slow down the audio 1/25 or 4% to keep it in sync (and then pitch correct to not drop pitch). At this point you could send out your audio for audio post at the correct speed. HTH Philip
i'd contradict Philip, and say that normal workflow in 24/25 PAL land is to work at 24fps.
especially if you plan to finish to film which will then be projected at 24fps. in FCP you have a few options: 1) monitor on 25fps "television" monitors. learn to live with the 1 extra frame every second 2) DONT monitor on 25fps "television" monitors. i cut a 24fps film this way. we worked in a DV environment, like you, and monitoring on our cinema display was fine. for screenings we "presented" QT files to a projector connected to a laptop. (the projector is seen as a second desktop by the system) some DVDs we made had the extra frame. it didn't seem to bother anyone 3) use some other form of monitoring. plasma / LCD 4) use an Aurora card. this is the only card that will play your 24fps material smoothly to 25fps. rather than adding a frame a second, it inserts one field every half second. i don't think this is an option for you, as i think it uses a special codec, and you'd have to start over with your capturing cheers, nck
Rich,
You are on the right track. You absolutly want to work at 24. FCP did get the well established 12+1 field pulldown method to smooth out 24fps playback to PAL displays in v5.0. This pulldown method is known as 24@25 Pulldown in FCP and can be selected in the Preferences. The way it works is to dupe 2 fields every second; for a much more detailed explanation check out Micjael Phillips article - this is how Avid's have done it for years: [www.24p.com] There may be a incompatibity here with the Kona card though, not sure as I don't have one, but recently I read a report that this pulldown method in FCP did not operate with a Decklink card. It works over firewire (although this will involve the nasty FW delay), but I just don't know how it operates with 3rd party cards. Go find the setting in the Prefs and give i t a go! You say "...rendered my clips"; what does this refer to, since if you are capturing in the DV PAL codec I assume and working in a PA 24@25 sequence - there should not be any need to render, I wonder if this is due to the audio sample rate after the conversion, see note below: If possible I suggest you capture/import (for BWF get BWF2XML from Spherico) your original production audio rather than use the audio on the DVCAM since currently it will end up at 46080Khz after the Convert 25 to 24 process (assuming 48Khz starting point). It means you have to do the syncing yourself, but this is a much cleaner way to work and will mean an easier path to the mix. Not absoltuly needed, but worth noting if you have time. Good luck, Mark
Rich,
Reading more about this on the Decklink forum there is mention that only ETT is effected with PAL DV material, normal playback mode should work ok with the 24@25 Pulldown method selected. AJA cards are mentioned, but not Kona 3 specifically, but it sounds like you should be ok apart from ETT. The solution mentioned was to work in the Photo-JPEG codec - so it seems its only a PAL DV field handling issue with these types of cards: Link 1 Link 2 Again these are from the Decklink forum, but I believe that same will apply to the Kona. Mark
Thanks for all youir help guys
Things are moving along nicely... One little thing though...We've changed our pulldown settings from 24@25 pulldown to 24@25 repeat for our external monitor. It's certainly smoother than before but we still get a small blur every second. This is a bit worrying for screenings. Does anyone have any ideas how this might be solved Thankyou for your time Rich
Thanks for all youir help guys
Things are moving along nicely... One little thing though...We've changed our pulldown settings from 24@25 pulldown to 24@25 repeat for our external monitor. It's certainly smoother than before but we still get a small blur every second. This is a bit worrying for screenings. Does anyone have any ideas how this might be solved Thankyou for your time Rich
Hi Rich,
In theory 24@25 Pulldown would be smoother than the repeat method as it is adding two fields to smooth playback to a PAL monitor which sounds like the 'blur' you are seeing, but as you have found this is not the case and repeat is the method which gives the smoother results in FCP - I am wondering if perhaps the FCP methods are switched (bug?) as the way you describe the playback with Repeat is how I would expect it with Pulldown. I would talk to AJA also as they have very good support and I'm sure they could shed some light on what's going on. The other options are obviously to use Desktop Preview mode in FCP with an LCD for when your cutting and a DVI connected projector for screenings. I work every day with the 12+1 field pulldown (in an Avid though) and its completely accepted in PAL land, but the 24+1 frame method is not, so if this is what you have you need to find a solution with AJA or move to the pure 24fps displays. -- Mark
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