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Old August 22nd, 2006, 07:09 AM   #1
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1080PA or 720PN for 35mm film out?

Well, folks, I do believe I'm about to make the leap into theatrical production. Does anyone have experience (or links to reliable opinions) on which is preferable for eventual film out: 1080PA or 720 PN? Normally I'd go for the 1080, but I'm not sure whether the pulldown is more objectionable than the lower resolution.
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Old August 22nd, 2006, 08:13 AM   #2
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FCP can edit 1080 24p, just use Cinema Tools to get rid of the pulldown.
As far as the actual difference? I say do a test and shoot the same things in both modes.
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Old August 22nd, 2006, 11:37 AM   #3
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Many have noted that 1080 gives higher resolution than 720. But you can't over/under crank in 1080.

If it were me I'd go for 1080p 24fps if it's a straight shoot and you want the highest resolution, but I'd go for 720PN if varying speeds are important for your target style.
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Old August 22nd, 2006, 09:38 PM   #4
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Thanks... yeah, I don't expect to need VFR on this project. I suppose I'll end up having to shoot some tests, but at the cost of 35mm film-out (not to mention the problem of finding a screening room to project it here), I was hoping to find someone who'd already done it. I've noticed some very apparent pulldown frame artifacts in some video-to-film projects (notably Murderball), but I'm not sure if it's regular pulldown or if I'm seeing some other motion effect in post on top of the pulldown.

Unless I'm wrong, there's no way to shoot 1080/24 (on the HVX) without there being pulldown on certain frames of the final film-out. I think 720/24PN is the only way to get a true clean frame for each frame of film. (If I'm reading the pulldown diagrams wrong, by all means tell me!)

I'm also reading that some inverse-telecine processes soften the image to help mask the interleaved pulldown frames.... and that the end result is resolution no better than 720/24PN.

If anyone has access to real-world test results on this (not necessarily specific to the HVX... this applies to all 1080/24 over 60 digital cinematography), I'd sure appreciate it. This may be a call for the CML...
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Old August 22nd, 2006, 10:02 PM   #5
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Quote:
Originally Posted by Scott Auerbach
Unless I'm wrong, there's no way to shoot 1080/24 (on the HVX) without there being pulldown on certain frames of the final film-out.
Why would you think that? That's completely not accurate. 1080/24pA can be edited in FCP or EDIUS as native 24p with no pulldown artifacts of any type, just straight raw 1080/24p. And you can extract the pulldown out of 1080/24pA footage in Raylight to end up with pure straight 24p.

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I think 720/24PN is the only way to get a true clean frame for each frame of film. (If I'm reading the pulldown diagrams wrong, by all means tell me!)
Okay, I'm telling you. You can get exactly as clean frames from 1080, you just have to use a program that knows how to extract the pulldown.
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Old August 22nd, 2006, 11:57 PM   #6
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barry, question then...
other than variable frame rate, and if the color renditions of both 720p and 1080p are the same for this camera, why would anyone opt for 720p over 1080p, especially for a filmout...
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Old August 23rd, 2006, 01:26 AM   #7
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It might work better for workflow as you can get twice as much time on a P2 card or whatever format you are storing on with 720 rather than 1080.
This can be a significant factor.
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Old August 23rd, 2006, 09:43 AM   #8
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Originally Posted by Barry Green
Why would you think that? That's completely not accurate. 1080/24pA can be edited in FCP or EDIUS as native 24p with no pulldown artifacts of any type, just straight raw 1080/24p. And you can extract the pulldown out of 1080/24pA footage in Raylight to end up with pure straight 24p.
Well, 'cuz I'm a dope, I guess ;-) And your book hasn't arrived yet!

What I've seen certainly seems to point to the frames in 24-over-60 as being interpolated frames created by blending various pairs of fields from the 60i recording.

There's only two ways to create a frame from 60i fields...either you have a raw frame with the interlaced-field jaggies on any areas of movement, or you have a frame that's been artificially interpolated by smoothing out the areas of difference between the odd and even fields. I suppose some of the really high-end software does that interpolation with great results, but I was concerned about softening or edge artifacts.

Since the camera itself is recording 60i the whole time (in 1080), I assume the creation of 24 progressive frames from those 60 fields happens in post, and the results probably vary depending on what system you're using. I'm primarily an Avid guy, but the Adrenaline I work on doesn't have the HD expansion board yet, so I hadn't tested it. I own a copy of FCP, but I'm really just at the flailing-around stage of learning it.

When you say "extract the pulldown out of 1080/24pA footage in Raylight to end up with pure straight 24p" I assume you're still talking about interpolation. That's really ~not~ the same thing as recording true 24p. And I always assumed the 720/24PN setting was what I'd consider "true" 24p--individual progressive frames created in-camera straight off progressive CCDS without jumping through mathematical hoops to blend two interlaced fields separated in time.

Am I makin' any kind of sense here?
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Old August 23rd, 2006, 12:16 PM   #9
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An additional point to consider in the 720 vx 1080 decision is are you going to do any CGI work in post with your footage? Results from side-by-side tests showed that a cleaner matte can be pulled in the 720p mode. So, even though the filmout may have a bit better resolution, if there are greenscreen shots, the artifacts will be more evident tif shot in 1080.

As far as the pulldown cadence not allowing for a "clean" 24p output for the filmout, I think you are not quite accurate in how the progressive frames are stored on the P2 format. I believe that in the 1080p24 format, a progressive frame is pulled off of the CCDs with the same clocking, and then it is split into two fields and stored in concurrent frames interlaced. Barry has already outlined how that process is reveresed in post and true progressive frames are reassembled.

If interlace artifacts are in a filmout version from progressive footage, the likely culprit is both lazy reverse telecine, and not catching a bad pulldown cadence setting of a clip.

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Old August 23rd, 2006, 01:44 PM   #10
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Quote:
Originally Posted by Scott Auerbach
What I've seen certainly seems to point to the frames in 24-over-60 as being interpolated frames created by blending various pairs of fields from the 60i recording.
No, that's backwards. It's interlaced frames created from splitting apart progressive frames. Exactly the same way as film gets telecine'd to video.

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There's only two ways to create a frame from 60i fields...either you have a raw frame with the interlaced-field jaggies on any areas of movement, or you have a frame that's been artificially interpolated by smoothing out the areas of difference between the odd and even fields.
On other cameras, maybe. But not the HVX. The HVX doesn't start with interlaced frames that it tries to blend into a simulated progressive frame; that's what Canon and Sony do. The HVX starts with a progressive frame, and only a progressive frame. It records those progressive frames within an interlaced data stream, because 1080 DVCPRO-HD is only interlaced.

Look at 1080/24pA footage, you'll see there are four straight progressive frames, followed by one "split frame". That "split frame" is formed by using half of the frame before it (the even lines, presumably) and half of the frame following it (the odd lines, presumably, or maybe it's the other way around). Point is, that "split frame" is only there to "pad out" the sequence, to get 24 frames padded out to 30. Drop that split frame and what are you left with? 24 original pure progressive-scan frames.

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When you say "extract the pulldown out of 1080/24pA footage in Raylight to end up with pure straight 24p" I assume you're still talking about interpolation.
Nope. I'm talking about reversing the "telecine" process to restore the frames to their original 24p nature. In 24pA you do that by just ignoring the artificially-created "split frame". In 24P mode (3:2 pulldown) you have to divide the frames back up into fields and re-sort them to assign the right fields together, and once you do that you can treat them as progressive frames (because they're NOT fields, they are halves of a progressive frame).

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That's really ~not~ the same thing as recording true 24p.
The way the DVX, XL2, and HVX do it, yes it is.

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And I always assumed the 720/24PN setting was what I'd consider "true" 24p--individual progressive frames created in-camera straight off progressive CCDS without jumping through mathematical hoops to blend two interlaced fields separated in time.
It is. And 1080/24p is exactly the same thing, and so is 1080/24pA. It just gets recorded in a 2:3 pulldown or 2:3:3:2 pulldown so it "fits" in the interlaced data stream, but it's progressive footage and can be restored back to its original pristine progressive nature very easily.
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Old August 23rd, 2006, 01:47 PM   #11
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Quote:
Originally Posted by Paul Nordin
An additional point to consider in the 720 vx 1080 decision is are you going to do any CGI work in post with your footage? Results from side-by-side tests showed that a cleaner matte can be pulled in the 720p mode.
I haven't seen those tests, but I can say that something's wrong, that isn't true nor can it possibly be true. Someone messed up somewhere.

1080 mode contains the identical same image, the identical same picture, the identical same color and the identical same latitude, the identical EVERYTHING, as 720 mode does. It just has more of it. Both modes start out internally at 1920x1080, and go through the exact same processing. Everything is identical between them right up until the instant that it gets recorded. At that point the 1080 mode gets recorded at 1280x1080 (or 1440x1080 in the 50Hz version), and those resolutions are high enough to retain almost every bit of detail the HVX can generate. Whereas in 720p mode the image gets scaled down to 960x720 before recording. That results in some detail loss.

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So, even though the filmout may have a bit better resolution, if there are greenscreen shots, the artifacts will be more evident tif shot in 1080.
Disagree 100%. Everything about 1080 is just better. Any artifacts that show up will be smaller in 1080 mode because the image is spread across a frame that's twice as large.

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If interlace artifacts are in a filmout version from progressive footage, the likely culprit is both lazy reverse telecine, and not catching a bad pulldown cadence setting of a clip.
Exactly correct!
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Old August 23rd, 2006, 01:49 PM   #12
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Originally Posted by Lonnie Bell
other than variable frame rate, and if the color renditions of both 720p and 1080p are the same for this camera, why would anyone opt for 720p over 1080p, especially for a filmout...
Leonard answered this -- the only reason to opt for 720 is if you need more recording time on the cards. You trade a small (very, very small) reduction in picture sharpness in exchange for getting 2.5 times as much recording time. Lots of people seem to think the tradeoff is well worth it.

But if you're looking to extract the absolute maximum from the camera, 1080p does that.
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Old August 23rd, 2006, 02:28 PM   #13
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Originally Posted by Scott Auerbach
Well, folks, I do believe I'm about to make the leap into theatrical production. Does anyone have experience (or links to reliable opinions) on which is preferable for eventual film out: 1080PA or 720 PN? Normally I'd go for the 1080, but I'm not sure whether the pulldown is more objectionable than the lower resolution.
Perhaps you should try starting out on a less technically challenging project. There's no better teacher than experience.
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Old August 23rd, 2006, 03:04 PM   #14
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Perhaps you should try starting out on a less technically challenging project. There's no better teacher than experience.
Too late! ;-)
I'll run tests, but I've been doing "less challenging projects" for 20 years. I've raised the money; the project is a 'go.'

There's really nothing challenging about it... I'm just trying to figure out the pro/cons of the two formats.
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Old August 23rd, 2006, 03:18 PM   #15
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Originally Posted by Barry Green
No, that's backwards. It's interlaced frames created from splitting apart progressive frames. Exactly the same way as film gets telecine'd to video.

--snip--
On other cameras, maybe. But not the HVX. The HVX doesn't start with interlaced frames that it tries to blend into a simulated progressive frame; that's what Canon and Sony do. The HVX starts with a progressive frame, and only a progressive frame. It records those progressive frames within an interlaced data stream, because 1080 DVCPRO-HD is only interlaced.
Ahhhhhhhhhhhhhhh
This was totally NOT clear from the material I'd read.

Panasonic's own chart of recording times/formats describes 1080/24 as being over 60i and 720/24 as being over 60p. Nowhere did I find a description of exactly what was going on in terms of how the signal was processed, though.

What I implied--incorrectly, obviously--was that in 1080 mode the HVX worked like the Sony and Canon, and in 720 it was a true progressive signal.

Thanks for clearing THAT up!
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