.What's the best method to slomo 24P????

[GeoffB]

I shot a wedding in 24P and need to slow down many segments and am not at all happy with the slow motion I get from some of my faster footage. Is there anything I can do in Final Cut Pro 4 to make it smoother or less noticeably jittery?? I've just done a slow motion render at 30% with frame Blending. Thanks in advance for your help....

Geoff B.

[Barry_Green]

I do not have the answer for you, but after extensive playing with the various modes I came to the determination that if you intend on slowing something down, you should shoot it in 60i. I was able to get by far the best slow-mo results from footage that was shot in 60i, vs. 24P or 30P. The small tradeoff in vertical resolution was more than made up for in much smoother temporal motion.

So, that doesn't help you here, I know, but for anyone who's contemplating shooting something with the idea of implementing slow-mo in the future, go 60i!

[GeoffB]

Well yeah, that doesn't help me right now. Thanks anyway. Besides, for future shoots, if you don't know which segments will be slowed down, how do you decide when to use 60i? I mean here I have this beautiful 24p image and I need to probably scrap it and shoot all 60i images? I just don't think the 60i image looks anywhere near as nice as the 24p thus the reason why I bought this camera.

There has got to be a way to smooth out the 24p slow motion with better blending. If anyone knows any trick or technique, I would really appreciate it. Perhaps for future projects, I should take into consideration the motion rules that filmmakers use with their 24fps images in my preproduction planning. I mean I'm doing this to facilitate actual narrative filmmaking so, maybe this could be incorporated.

My "fast stuff" is probably best viewed as violations of the motion rules of filming which are to be stringently avoided. I know there are some really gifted people on this board who could maybe further this discussion or at least point some of us in the right direction.

Thanks,
GeoffB

[Zoomforce]

The best way to do slow mo for 24p is to shoot your slow mo scene at a faster rate.. just like they overcrank film... unfortunately the only option you have is a 20% slowdown by shooting 30p with the same settings. Most NLE's can do a slow mo, but make sure you dont get it to interpolate the frames between as it most of the time will look like crap.

[Barry_Green]

Okay, sorry to de-rail the question, I'll try to get back to helping you out...

Have you heard of Twixtor? People recommend it all the time, but I've tried it and can't get consistently good results from it. It's a program that adds generated frames, and when it works, it works amazingly well.

Here's a sample video Stephen Van Vuurren did:
http://www.sevensmilingsharks.com/media/twixtor.wmv

Now, keep in mind that's a 24-fps video, but he shot it on a motor-drive SLR at 2 frames per second -- so Twixtor was creating 22 out of the 24 frames per second. There's obviously some problems, but - DANG. If it can generate information like that, it certainly should be able to interpolate enough to give you a 50% slow-mo effect.

They have a downloadable demo, so maybe you could try it out and see if it does what you need.

[GeoffB]

So filmmakers who use film for slow motion have to overcrank or double the speed of their film to gather enough image to slow it down? Then they also have to know when they are going to need something slowed down in advance so they know what speed to film it at?

This obviously wouldn't work too well in documentary filmmaking or event filmmaking unless its highly scripted. Does this mean that I can't shoot 24p all the time and expect to use any of the shots for slow motion?

The shots that I have that look O.K. are the ones that don't seem to violate the motion rules as I understand them:

1. don't film static shots with objects moving directly across the frame.
2. only use motion that is coming towards the lens or away from the lens as this is slow enough motion for 24fps to keep up with it
3. if you dolly a shot you must follow your subject in the frame as they are moving or if they are still, turn the camera to stay on them as you are moving- all to hide the motion that is exposed by 24fps filming.

Could someone check my math here. Don't know enough about filmmaking to use this camera to its fullest extent yet.

Thanks,
GeoffB

By the way, I'm really glad there's a board like this! You guys are a huge help.

[Barry_Green]

So filmmakers who use film for slow motion have to overcrank or double the speed of their film to gather enough image to slow it down?

Yes. You shoot at a higher speed (in the old days you used to actually hand-crank the camera, hence turning the camera faster was called "overcranking"). That gives you more frames, which when played back at 24fps would obviously take longer, hence slow motion.

The DVX is capable of this to a slight degree: you can shoot 30P and import that into a 24fps timeline and have the same effect as if you'd shot film at 30 fps and then played it back at 24. Or you can shoot 60i and slow that down a lot, exquisite slow motion, at the expense of a little vertical resolution.

Then they also have to know when they are going to need something slowed down in advance so they know what speed to film it at?

Exactly. That's how it's been done for the last 100 years.

This obviously wouldn't work too well in documentary filmmaking or event filmmaking unless its highly scripted.

Well, it's how it's done... I mean, there's no other way to do it. The only other way to do it is to step-print, doubling frames as you make your final print, but that's very choppy (same results as you're getting now). When transferring to video you have some more options, you can transfer the 24fps at a 20fps rate, which will give you slower motion, but still choppy. The ONLY way to get smooth slow motion, in film, is to shoot it like you intend for it to be slow-mo'd, meaning to overcrank.

Does this mean that I can't shoot 24p all the time and expect to use any of the shots for slow motion?

Well, yeah. If you're going to want to slow-mo it, you'll get much better results from 30p, and infinitely better results from 60i.

That, or use Twixtor (if it provides satisfactory results for you).

The shots that I have that look O.K. are the ones that don't seem to violate the motion rules as I understand them:

1. don't film static shots with objects moving directly across the frame.
2. only use motion that is coming towards the lens or away from the lens as this is slow enough motion for 24fps to keep up with it
3. if you dolly a shot you must follow your subject in the frame as they are moving or if they are still, turn the camera to stay on them as you are moving- all to hide the motion that is exposed by 24fps filming.

Could someone check my math here. Don't know enough about filmmaking to use this camera to its fullest extent yet.

Those are exactly the rules that you should follow to minimize the strobing that occurs from the slower sampling rate (i.e., you'd get smooth film or smooth 24P doing that). But, that doesn't have anything to do with slow-motion. Slow-mo is accomplished by overcranking.

"regular" video can be slowed down all you want because it's sampling motion at 60 times a second. 24P gets a motion sample only 40% as often. So there's just not enough info there to make smooth slow-mo shots out of. 60i video, when slowed to 50% speed, uses one field from each and every 60th of a second to generate a frame. You have 60 motion samples to choose from. But with 24P, you've only got 24. That's all there is. If Twixtor works for you, it can generate the missing frames you wished you had shot in the first place... other than that, maybe you can try a motion-blur effect or something, but basically if you shoot it at 24P you're in the worst position to make slow-mo footage.

24P = excellent film look, lousy slow-motion
30P = not as good film look, a little better slow motion
60i = no film look whatsoever, but great for slow motion.

[Zoomforce]

Wow.. I just love your huge ass responses Barry.. man you deserve that Guru Title :)

Anyways, the only other way to do it is to smart resample or interpolate the frames between each frame in slow mo.. this gives a smooth movement, however it also adds a side effect of something that looks like extreame motion blur. Twixtor I believe does this, and Vegas has something called Velocity Enveloped that you can use as well... Like Barry though I have never had great success with that.

[GeoffB]

Wow. Word. Hey I think you guys have answered every question I have. Thanks, you guys are great. Barry I like your conclusions. Nice and simple.

I guess I'm really glad I have this camera because at this price to have the choice between the three frame rates is great.

Thanks again for the help,
GeoffB

[Guest]

I am a newbie so please bare with my ignorance.. But If I shot something at 24p (not advanced) and export it out of FCP4 at the normal 29.97 then send it into after fx to slow it down would that work getting smoother slomo? Then just reimporting it back into FCP4? Just curious cause thats kind of a bummer cause I love slomo.. But I also love the look of 24p? I guess it's whatever you love more..

[Barry_Green]

I guess I'm really glad I have this camera because at this price to have the choice between the three frame rates is great. *


Three frame rates? With a little help in post, the DVX can shoot at six frame rates: 1, 12, 15, 24, 30, and 60. And the DVX100A can do even more: 1, 2, 3, 4, 6, 7, 12, 15, 24, 30, and 60. We all wish for more high-speed frame rates, but unfortunately there's no way to get them...

Thanks for all the kind words you guys offer. I try to help whenever I can. Experiment with Twixtor and see if it offers you what you need. Other than that, yes, you kind of have to pick your frame rate depending on what you want to accomplish, but again, keep in mind no other camera can do anything like this, so (like we used to say in software development) "it's not a bug, it's a feature!" :)

[DVX100Shooter]

You know what....I have heard people say if you know your going to slo mo a shot when your shooting or about to shoot a particular shot to switch your dial to 30p for smoother motion in post. Now I recently shot a Car Show in 24p mode and I just got done editing it with FCP and I have some shots of models next to cars and some shots of them in the bikini contest and I slowed them down just by going into the settings for that particular clip and changed the speed to 50% and it turned out nice after it rendered! There was no need for me to shoot in 30p.

[Barry_Green]

Hey GeoffB, I just had a thought...

You are editing in a 24P timeline, right? If not, if you're editing in a 60i timeline, that would make your 24P footage slowing down look just horrible (duplicated fields, etc.) So if you were in a 60i timeline, try importing the clip into a 24P timeline and slow it down there. It'll still have choppy motion, but it would look much better than if you were trying to slow down a 3:2 pulldown clip!

[magicdavek]

I work with Final Cut Pro, After Effects and worked (past tense) with Adobe Premiere (a nice program, but no match for FCP). I've never used 24p, however (I'm a DVX wannabe). I've used slow motion in each program. Here's a possibility to try. Those more knowledgeable may point out that this may not work for some technical reason. Also, this wouldn't help unless you know ahead of time you're going to use slow motion. Basically, shoot in 60i. Import into FCP and slow to desired level. Then (and here's what I haven't tried) convert to 24P in FCP or After Effects. Finally, add film look with software like Digieffects "CineLook."

By the way, have any of you used "CineLook?" It would be interesting for someone who uses both a DVX100 and "CineLook" to tell us if there are any presets in "CineLook" that could help match video shot on other cameras (e.g., VX2000/PD150) to the DVX100's output. This may be a tough question because it seems that there are several settings on the DVX in 24P mode. But anyway, it would be interesting if "CineLook" could be used as an adjunct to get footage from other cameras to roughly match the DVX100, at least approximately-so the untrained viewer may not notice.

[xander76]

Another thing to look at if you are not happy with slomo is Digital Anarchy's http://www.digitalanarchy.com/ ReTimer SD. It's a plug-in for AE, FCP, or combustion that does time-warping of clips. I saw a demo reel last night at the FCP User Group party at MacWorld, and I was pretty impressed. However, I have not played with it myself, so I can't vouch for it.

(FYI, I am not affiliated with Digital Anarchy.)

[Carrington Benz]

Is this the same product ? - I heard about this product a while back & someone directed me to this site called "realviz".

http://www.realviz.com/products/rtsd/index.php

This looks like the kind of slomo I need in my life!!! 8)

[xander76]

From the digital anarchy website:

Based on the engine of REALVIZ's award-winning application, ReTimer 2.5, this innovative technology enables calculation of each and every pixel move.

So it sounds like it's at least based on REALVIZ's plug in if not the exact same thing.

[Guest]

Hi Gang.

A bit new to all this, so please correct me if I'm wrong.
In FCP4 could you not use the time remapping tool to slow down the footage and then simply add a deiinterlace filter to take care of any "flicker" that would occur on an NTSC monitor?

travis

[jaredalv]

You also need to check out Boris FX Red's 'Optical Flow' filter. Here's the link:

http://borisfx.com/products/RED/feature_overview_revised.php#over

then scroll down to the section "Optical Flow Technology".

This is an effect rendered by the masters over at the 'Cow.

Hope this helps.