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Old May 8th, 2006, 10:13 PM   #1
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Can 720 30p be converted to look like 24p?

Has anyone shoot in 720 30p and tried in post to get the same
look and feel of 24p footage? Any thoughts or ideas or experience,
please share. thanks...
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Old May 8th, 2006, 11:06 PM   #2
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It's possible if you use some kind of motion-based interpolation, but that kind of software is pretty expensive. I'd just leave it alone unless you're outputting to film, very few will be able to tell the difference.
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Old May 8th, 2006, 11:10 PM   #3
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I see a big difference between 30p & 24p footage from the
HD100U. It is a very different look from 30p to 24p.
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Old May 8th, 2006, 11:18 PM   #4
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What editing software are you using? We are using FCP 5.1
and conform 30p to 24p using Cinema Tools. Most legacy stock footage is plain vanilla 29.97. Many clients are requesting some 30p to 23.976 conversions.
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Old May 9th, 2006, 03:01 AM   #5
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Quote:
Originally Posted by Rob Stiff
I see a big difference between 30p & 24p footage from the
HD100U. It is a very different look from 30p to 24p.
Not saying you are wrong, but we know 25p doesn't look different than 24p. So when you say you see a BIG difference, that big difference would have to occur at 26, 27, 28, 29, or 30p. Hard to believe it would be 26. So that means something dramatic must occur at 27, 28, 29, or 30p.

Given equal 180 degree shutters, I can image a tiny difference -- but a big difference -- I'm not convinced. In fact, film for commercials has been shot at 30p to avoid pull-down.

So, I suspect what the difference is -- is that when you watch 24p on a video monitor you are seeing 2:3 pulldown. That is the BIG difference. BUT YOU DO NOT SEE PULLDOWN WHEN YOU WATCH FILM IN A THEATER.

Therefore, you should be able to get a TRUE film look using 30p. In fact, a more true film look than shooting 24p!

Unless you really go to film, shooting 30p -- with each frame presented twice upon video viewing -- is very much like film where each frame is flashed twice by the spinning shutter. You get the SAME strobing artifacts.

You get nearly the same shutter speed and nearly the same frame rate.

That's the virtue of 30p -- plus no editing issues.
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Old May 10th, 2006, 03:40 AM   #6
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Quote:
Originally Posted by Steve Mullen
Therefore, you should be able to get a TRUE film look using 30p. In fact, a more true film look than shooting 24p!

Unless you really go to film, shooting 30p -- with each frame presented twice upon video viewing -- is very much like film where each frame is flashed twice by the spinning shutter. You get the SAME strobing artifacts.

You get nearly the same shutter speed and nearly the same frame rate.

That's the virtue of 30p -- plus no editing issues.
why does 30p look more like film than 24p? cuz of the "strobing artifact"? why is getting "nearly the same frame rate" better than getter the actual frame rate of film?
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Old May 10th, 2006, 04:41 AM   #7
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Steve's point is that there is no way to actually view true 24p. Almost any way you view it comes out as a 3:2 pulldown, which has a jerky feel to it.
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Old May 10th, 2006, 04:56 AM   #8
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Quote:
Originally Posted by Stephan Ahonen
Steve's point is that there is no way to actually view true 24p. Almost any way you view it comes out as a 3:2 pulldown, which has a jerky feel to it.
Exactly! Amazing that folks think by shooting 24p they will be able to view 24p. They can only see 24p if they convert to film.

If you are not going to film -- you'll see 60p or 60i with 2:3 pulldown when you watch on ANY video screen. The 2:3 "judder" look is NOT the same as the "strobing" that comes from 24p film or 30p video. Completely different!

Which means if you really want a TRUE "film look" -- shoot at 25p or 30p.

Which is why the HD1/HD10 works fine for a film look even though it doesn't have 24p.
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Old May 10th, 2006, 05:10 AM   #9
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Hi Steve,

What if you shoot 30p and you end up going to film?

Maybe that's a good question for Andrew Young?

(I would love to shoot 30p because FCP does it natively now)

Thanks,

Tom Chaney

(and for those of us that have already started shooting in 24p, can we mix footage?)

Last edited by Tom Chaney; May 10th, 2006 at 05:48 AM.
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Old May 10th, 2006, 09:29 AM   #10
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Andew Young shot at 30p and when output to film let is play frame for frame, meaning that it was 30p but projected at 24p giving you a very slight slow mo effect. Obviously if there was sound this would cause a problem but his footage did not have it and he mentioned he liked that look for his nature footage.

If you think you might go to film then shoot 24p. If not, use 30p, the progressive at 30p will give you a good look. If you only believe that you can get the real film look by doing 24p then shoot it but what I realy suggest is that you shoot the same thing at 24p and 30p, then burn a DVD and watch it on your tv. See what you think and make your own artistic decision.
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Old May 10th, 2006, 10:01 AM   #11
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If going to DVD..
If you like the look of 24P movies when viewing DVDs, than capturing 24P with the HD100 and transfering to DVD should yield the same look.

This is a correct statement, right?

Last edited by Steven Thomas; May 11th, 2006 at 01:20 AM.
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Old May 10th, 2006, 10:31 AM   #12
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I believe the original question was "Can 720 30p be CONVERTED to look like 24p?" I assume that Rob is asking this question because the footage is already in the can, and we're not talking about what he _should_ have done...(?)

Rob: It is much easier to convert 60i to 24p than 30p to 24p. Film houses that transfer video to film generally don't accept 30p source material, whereas they will gladly accept 60i source material. The reason for this is that interlaced video has greater 'temporal' resolution, whereas progressive video arguably has greater spacial resolution. When you convert from 60i to 24p you have at your disposal a set of snapshots at every 60th of a second which can be matched convincingly (for some) to 24 fps with a 3:2 pulldown.

If you have started with 30p, you could convert it to 60i, then down to 24p again. When you do this, however, you will still discover that the 2:3 pulldown produces a move-jerk-move-jerk kind of feeling, because wheras 24p has captured 1/48th of a second of motion at intervals of 1/24th of a second, 30p has captured 1/60th of a second of motion at intervals of 1/30th of a second. Frame number one will be identical, frame number two will be out by .008 seconds, frame number three will be out by .016 seconds, frame number four will be out by .025 seconds, and so on.

These may seem like small differences, but the eye will detect it, even if your motion-interpolation software is excellent.

Short answer: I'd leave the footage the way it is, at 30p.
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Old May 10th, 2006, 11:18 AM   #13
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I'll throw my hat into the ring on this one...

When shooting film for broadcast and a monitor is visible in the shot, there are two typical ways to avoid a roll bar in the screen; have the playback video converted to 24 fps (with a capable monitor) or shoot the film at 30 fps which will sync with video.

If the latter process is chosen (not very often these days), there may be a single shot of 30 fps transferred at 30 cut in with 24 fps transferred at 24 fps footage (I make the transfer distinction because, as being discussed above with Andrew's footage, transferring at a different frame rate results in an undercranked or overcranked appearance). The result of this is a cadence that looks very different than that of the surrounding shots, enough so that I used to say to myself "here comes the pan to the TV" when such a shot would appear. It's pretty obvious. Not huge, life-changing or radical, but if one's eyes are attuned to 24 fps, it's apparent.

Now, I've also sat in a dailies projection room and seen film footage projected at 24 and then occasionally sped up to 30 (in an effort to plow through hours of dailies). There is definitely a difference in appearance with 24 and 30 fps projection. It's quite similar to viewing 24p vs 30p originated footage on a monitor, regardless of pulldown or no pulldown being in the mix. It has something of a "video" look to it, in fact.

Steve, while it's agreeable that the difference between 24 and 25p is hard to detect, I think it's not too hard to imagine that the CUMULATIVE effect of the incremental alteration of information between 24 and 30 can result in a visual change. Much in the same way that Andrew's footage shot at 30p had a noticeable slowdown when transferred frame to frame onto 24 fps film, yet films shot at 25p and transferred to 24 do not.
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Old May 10th, 2006, 01:21 PM   #14
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Quote:
Originally Posted by Charles Papert
Steve, while it's agreeable that the difference between 24 and 25p is hard to detect, I think it's not too hard to imagine that the CUMULATIVE effect of the incremental alteration of information between 24 and 30 can result in a visual change. Much in the same way that Andrew's footage shot at 30p had a noticeable slowdown when transferred frame to frame onto 24 fps film, yet films shot at 25p and transferred to 24 do not.
I don't disagree that the move from 25p to 30p will be visible to some. My original point was that the BIG difference someone saw was more likely the 2:3 pulldown ON vs OFF -- than the change in rate.

My second point, when questions were asked, was that we really should differentiate between a "Telecine-look" verses a "Film-look." I'm not saying one is good and the other is bad. I simply realized that a whole bunch of new folks are shooting 24p without an understanding of what they were really getting.

My third point, is the vast majority of low-temporal rate video will NEVER go to film. And, given the hasstle of capture, mixing with deinterlaced 60i, and export -- there is an advantage to shooting 30p.

When you say you can see the difference of a 30p shot within 24p, I'm not sure this can be generalized. First, you know the shot is coming. Second, it is a switch from one rate to another. Third, I'm not sure if the scene were lit as though it were film, the typical audience could see much of a difference.

Now, if you really want to create a "look less like video" at 30p -- turn-on the Motion Filter. This adds a judder to pans that will likely trick most of the audience.

And, that's what "film look" is about. It's only a trick to fool the audience into believing either that video wasn't used or that film was used.

I'm watching a lot of films from the `70s and `80s on INHD. These film have wonderful grain. There is no way IMHO that any video camera is going to give a result that looks as good as these films. To me, film has a texture that 24p video does not. (I love the grain in my old 16mm film.)

So when you say that 30p has a bit of a video look -- I feel modern film stocks have already moved film toward looking like video. No wonder Lucas can make the switch to all electronic motion pictures.
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Old May 10th, 2006, 04:48 PM   #15
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Just a question, if you shoot 30p and end up going to film, why not just project the film at 30 fps in the theater? I recall that movie studios stick with 24 fps despite TV's use of 60i because going up to 30 fps would increase their film costs 25%. If you're willing to pay for the extra film in the end, though, why not just avoid 24p altogether and project at 30?
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