Import 30p clip to timeline then change comp setting to 24p and render: Is this wrong?
by Carlyle Gordon
on
Sep 22, 2009 at 1:34:07 pm
For 24p film look, I have footage shot on Canon HV-40 set to 30p mode. I import into AE, then have AE automatically create new comp to match clip settings. I then change comp settings from 30p to 24p and render out to an uncompressed clip.
Am I making my clips more film-like or just making a mess of things?
Re: Import 30p clip to timeline then change comp setting to 24p and render: Is this wrong? by Dave LaRonde on Sep 22, 2009 at 2:34:03 pm
[Carlyle Gordon]"Am I making my clips more film-like or just making a mess of things?"
You're making a mess. You can illustrate it to yourself by doing the following:
Draw a long line on a piece of paper. On one side of the line, make marks to divide it into 30 equal parts. On the other side of the line, make marks to divide it into 24 equal parts. Now examine how those parts line up. You'll see that it's an irregular pattern, which extends to the motion you'll see in a rendered movie. It ain't pretty.
There are four ways to get 23.976 footage:
Shoot 24pn -- look up the term if you have to.
Shoot 24p and remove the pulldown.
Shoot 29.97, and use specialized frame rate conversion software like Magic Bullet, Twixtor or ReelVision to create 23.976 footage.
Shoot 29.97, and use AE to do the frame rate conversion, which is hit-and-miss at best.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Import 30p clip to timeline then change comp setting to 24p and render: Is this wrong? by Kevin Camp on Sep 22, 2009 at 3:50:20 pm
personally, i prefer 30p to 24p for broadcast. 30p has 20% greater resolution and will look smoother when broadcast or played on any device that can't show 24p (which is any tape machine or interlaced tv set).
30p footage displayed on progressive devices will look the same as on interlaced devices. any 24p footage on interlaced devices will get a pulldown added to make it 30i. this will not only add interlaced frames to your progressive footage, but also a slight stutter to movement.
personally, i would only work in 24p by choice if the project was going to film or i wanted the end result to go to both ntsc and pal -- it's easy to take 24p and change the frame rate to 25 for pal, and it is easy to add a pulldown to get 24p to 30i for ntsc.
Re: Import 30p clip to timeline then change comp setting to 24p and render: Is this wrong? by Carlyle Gordon on Sep 23, 2009 at 12:30:27 pm
I suppose if you are OK with the video look this is OK, but if you want a more cinematic shot on FILM appearance, you will need to slow things down a bit somehow. 29.97 or 30p, has smaller scale "video look" written all over it. Don't get me wrong though. Shot properly 30p can look very cinematic.
Re: Import 30p clip to timeline then change comp setting to 24p and render: Is this wrong? by Dave LaRonde on Sep 23, 2009 at 12:52:46 pm
[Carlyle Gordon]"Shot properly 30p can look very cinematic."
...which is why as broadcasters who typically work on tight deadlines and little time to fart around with alternate frame rates, Kevin and I both tend to say, "Film, schmilm!"
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Import 30p clip to timeline then change comp setting to 24p and render: Is this wrong? by Kevin Camp on Sep 23, 2009 at 5:28:19 pm
personally, i don't think there is anything about interlacing that says 'film'... and interlacing is what you're going to get on 3-out-of-5 frames if you have 24p in atsc (or ntsc).
it's fine for progressive dvds as long as you know it will be on a progressive capable tv, but otherwise it's interlaced. don't get me wrong, it's not awful, we've been seeing every film on tv with it since 29.97 was set as the ntsc frame rate, it's just not progressive and not film-like.... it's film-on-tv-like...
if you still want to get the 30p footage to 24p, then there are two other 'free' methods that may be better than just dropping every 5th frame.
the simplest method would be to drop the footage into a 23.976 comp, but enable frame blending (layer>frame blending>pixel motion). this should only be done if there are no cuts in the clip and should produce smoother motion, but may produce noticeable artifacts in interpolated frames.
the other would be to try andrew krame'rs frame rate conversion technique (i think it's still here in the tutorials section, if not check his videocopilot.net site). first you'll interpret your footage as 23.976 (file>interpret footage>main, conform the frame rate to 23.976). take that into a new comp and add the timewarp effect. set the speed to 125 (if you like math, 125 is derived from 29.97/23.976 x 100).
the advantage of using timewarp is you have some control over how frames are interpolated. look at the tuning settings to try and minimize artifacts on interpolated frames. 'extreme' filtering often helps as does tweaking the vector detail.
you can also add some motion blur in that can help make it look a bit more 'filmy' -- often video shutter speeds are much higher than typical film shutter speeds, giving video frames a 'tight' feel compared to a softer film feel, but that can come down to how the video was shot (ideally shoot 30p video at 1/60th shutter speed; 24p at 1/50th or either with 180 shutter angle if that's an option to look filmy), or the effect you were going for on the shot (like saving private ryan was purposely shot with a tight shutter angle -- around 45-90 -- for effect).
