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LHe 1080 24p to monitor problems

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11thIndian
LHe 1080 24p to monitor problems
on Jan 6, 2007 at 11:04:01 pm

I'm starting editing on a feature in FCP 5.12. It's being shot on Sony's XDCAM at 1080 24p. This is my first time working with 24p material since I got the LHe card. I wanted to test viewing 24p HDV material on my Sony Bravia 26" screen, so I took a HD trailer from Apple's site and re-exported it to HDV 1080p24 (as we'll be offlining at HDV).

When I try to play back the clip in the preview monitor, no mater which Kona video playback option I use, the file won't display on my monitor. Using the AJA KONA 1080i29.97 8bit setting, I just get a freezeframe at the start of playback. Using the AJA KONA 1080psf23.98 8bit, all I get is scrambled garbage on the monitor.

I CAN view the trailer (without rendering) if I drop it into a HDV 23.98 sequence, and set the Video Output to AJA KONA 1080i29.97. In this case I'm guessing FCP is doing the pulldown while playing back the sequence.

Shouldn't I be able to view HDV 24p material straight though the my Kona LHe card? I'm definitely going to need to be able to view material from the preview window during editing.

Thanks

Marcus R. Moore
Disproportionate Pictures


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Bob Zelin
Re: LHe 1080 24p to monitor problems
on Jan 6, 2007 at 11:53:50 pm

your limitation is your consumer monitor, that cannot display a 24 frame per second video image. Buy a monitor that can do this (like the Panasonic BT-LH2600W, or the now inexpensive Sony SDM-P234b 24" LCD monitor), and you can see the native 24p image out of your Kona.

Bob Zelin


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11thIndian
Re: LHe 1080 24p to monitor problems
on Jan 7, 2007 at 12:42:13 am

I know about true 24p capable displays, but can't the Kona do a realtime pulldown for monitoring, like FCP can out of the sequence?


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JeremyG
Re: LHe 1080 24p to monitor problems
on Jan 7, 2007 at 12:57:24 am

[11thIndian] "but can't the Kona do a realtime pulldown for monitoring, like FCP can out of the sequence?"

Yes and you found the way to do it. Set the output to 1080i like you did and you should be good.

Jeremy



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11thIndian
Re: LHe 1080 24p to monitor problems
on Jan 7, 2007 at 1:13:42 am

I tried another trailer and this one is working in both the preview and program windows. The difference is that the one trailer is showing up as 24fps, and the other (the one that's working) is showing up as 23.98. I've tried several times in Quicktime pro to export the HDV file as 23.98, but it still keeps showing up in FCP as 24. Weird...


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gary adcock
Re: LHe 1080 24p to monitor problems
on Jan 7, 2007 at 1:38:02 pm

[11thIndian] "I CAN view the trailer (without rendering) if I drop it into a HDV 23.98 sequence, and set the Video Output to AJA KONA 1080i29.97. In this case I'm guessing FCP is doing the pulldown while playing back the sequence."



The reason for this is your 24p content is really 23.98 not 24.
thats why it is working correctly at 23.98 - Video is almost never 24.0 fps.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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11thIndian
Re: LHe 1080 24p to monitor problems
on Jan 7, 2007 at 2:02:30 pm

After exporting several other trailers to HDV1080 24p, this seems to be the case. Everything that is 23.98 works fine playing from both the preview and program windows out to the monitor. The first trailer I tried (the Transformers trailer) is the only problematic one, which seems to want to be 24fps in FCP no matter how I try to force a 23.98fps frame rate when exporting from Quicktime pro. But if dropped into a 23.98fps sequence, this one will work as well, just not on it's own in the preview window.


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Bob Zelin
Re: LHe 1080 24p to monitor problems
on Jan 7, 2007 at 3:10:08 pm

Actually, Mr. Indian's problem is a real problem, and I saw this EXACT problem the first time I had to use a Sony HDW-M2000/10 VTR (which does not have 2:3 pulldown native to the VTR).

My client, who was new to the time, rented a CineAlta, and shot in 24p. Thats right, they shot at 24, not 23.98, which is a choice on the camera (and useful if you are going to print back to film). Of course, they were not doing this, but were ignorant at the time about the difference between 23.98 and 24p (these manufacturers DO make it confusing). Unless you have some fancy assed frame rate converter, if you shoot in true 24 - you are SCREWED with conventional equipment. To video people, 24p means 23.98 - just like normal video is 29.97, not 30 frames per second (when you shoot in film, shooting at 30fps does not mean you can edit with this until a pulldown is done on the telecine).

Unless you are George Lucas, NEVER EVER EVER set a camera for 24 frames per second - always 23.98. Of course, with this said, I fully understand that many products say "24" when they mean 23.98. What is killing me these days, is all the companies that call HD-SDI, just SDI. Well, is it standard def SDI, Hi def SDI, or auto sensing for both ?

Don't worry, however - as 2k and 4k become more popular, it will become even more confusing. And we thought that 44.1k and 48k digital audio was confusing - HA !

bob Zelin


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gary adcock
Re: LHe 1080 24p to monitor problems
on Jan 7, 2007 at 4:14:10 pm

[Bob Zelin] "they shot at 24, not 23.98, which is a choice on the camera (and useful if you are going to print back to film)"

Not true Bob.

The vast majority of filmouts are from video content at 23.98 not 24.0.
The only clients I know that are not matching video to film that shoot at 24.0 is NASA.

Mr. Indian, Bob is correct - most telecine is done at 23.98 so that the related issues concerning playback of SD content and the lack of displays that can truly play 24.0 material are only 2 of the reasons.

The main reason however is audio- shooting at 24.0 requires that the audio be sampled at 48.048hz to compensate otherwise the cost to deal with the offspeed audio adds up to major cost at the post stages.



gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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gary adcock
Re: LHe 1080 24p to monitor problems
on Jan 7, 2007 at 1:38:03 pm

[11thIndian] "I CAN view the trailer (without rendering) if I drop it into a HDV 23.98 sequence, and set the Video Output to AJA KONA 1080i29.97. In this case I'm guessing FCP is doing the pulldown while playing back the sequence."



The reason for this is your 24p content is really 23.98 not 24.
thats why it is working correctly at 23.98 - Video is almost never 24.0 fps.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows


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