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-   -   Good clean smooth musical video-like slow mo....how? (https://www.dvinfo.net/forum/non-linear-editing-pc/8555-good-clean-smooth-musical-video-like-slow-mo-how.html)

Chris Simmons April 11th, 2003 03:21 AM

Good clean smooth musical video-like slow mo....how?
 
Hi I have been watching music videos for a while...and I love the quality of slow motion they get. How do they get such clean slow mo effects without the ghosting I get when I add frame blending.

I watched a making of the video special on MTV. But I do remember a clear behind-the-scene shot of the main video monitor while the action was being recorded by the main camera. I saw 24 fps at the bottom of the screen. That particular shot that was one the monitor ended in the final music video in slow mo. It was clean.

So I figure, if they can get thses types of slow mo results at 24 fps, I should be able to get clean slow mo at 30 fps.

Is there some other trick or software they use?

Thanks alot for any help.

Tor Salomonsen April 11th, 2003 07:00 AM

I don't know what they use on MTV. But Vegas will give the sweetest slow motion you can imagine.

Mike Rehmus April 11th, 2003 08:50 AM

24 fps would result in a fast motion if run at 30 fps. It takes 60 fps watched at 30 fps to give you 1/2-speed motion. Very likely the slow motion is created the normal way with a film or video camera running fast. Software tries to do 'tweening' but it just is not as good or smooth as that generated by taking the shot at higher frame rates.

Robert Knecht Schmidt April 11th, 2003 10:01 AM

The "sweet" slomo seen on MTV is done by overcranking a film camera, or by a combination of that and other effects composited together in post, as with "bullet time" type sequences popularized by GAP commercials by Buf Compagnie and The Matrix.

While you'll never be able to achieve anything quite as nice with a video camera--even a CineAlta isn't capable of overcranking beyond 60i fps--there are specialized software programs such as RealVIZ Retimer that "tween" (interpolate) frames of motion video by computing motion vectors of pixels and edges. I don't know how good a result you'll be able to get with such software, but it's worth looking into if your project demands slow motion without the benefit of a film camera.

Henrik Bengtsson April 12th, 2003 04:24 AM

As Robert stated, the musicvideos usually uses a filmcamera working at a higher fps than 24. Many filmcameras can even do as high fps as 150 which would result in a very smooth and even flow.

The RealViz package ReTimer works by morphing from frame A and B to create the inbetween frames. This works to an extent and only with very special type of images. Generally it needs lots of contrast, and a very separated background. And you still can't go very much beyond the limits of "normal" slow-mo anyway because the morphing signs will be too evident.

So if you want the superslow-mo im afraid the only good way to get it is to go film.

/Henrik

John Threat April 12th, 2003 11:39 AM

Or, do playback at the music video slowed down, and have them act everything out in slow mo.

Bill Ravens April 12th, 2003 12:08 PM

you can "overcrank" with Vegas....render at 60fps, then slow it down with the velocity envelopes and re-render with "resample" enabled. The results are astonishingly smooth slo-mo.

Robert Knecht Schmidt April 12th, 2003 12:14 PM

Bill,

Any sample footage available?

Chris Simmons April 14th, 2003 12:22 AM

Bill do you know if there is a way to do this in AfterFX of Premiere or Combustion? I don't have access to Vegas at the time.

Trey Perrone April 14th, 2003 06:00 PM

how do you recommend going about this process of "overcranking" in vegas Bill? Im using the 4 version. i dont see any option listed when I open the render as box. the only way i know of changin speed so far is with the velocity envelopes. If you have any pointers i would relaly appreciate it. i recently slowed down some football clips by right clicking the clip and setting the undersample rate to .5 and they played pretty well on the pc, but when printed to VHS had a real strobelike effect that wasnt apparent on the pc. in retrospect maybe i should have changed the playback rate to .5

Bill Ravens April 14th, 2003 06:27 PM

Overcranking involves turning each field into an individual frame, resulting in 60 frames/sec, then slowing the motion back to 30 frames/sec. The price of doing this is a reduced rez. I haven't found a convenient way to do this in V4, but, it can be done very easily in VirtualDub. The resulting 60fps file is then imported in V4 for slomo with the velocity envelope and resample turned on..

I'll put a sample clip up at: www.geocities.com/ravens404
download the file called slomo2.mpg bt right clicking on that file(1.73 Mb)

Note: it's pretty low rez so I can upload it fast. The original is quite good.

Bill Ravens April 14th, 2003 07:48 PM

oops...forgot about this...V4 WILL overcrank.
Highlight the clip on the timeline, then select FILE/PROPERTIES.
From the menu that opens, you'll see a box called frame rate. The default values only go up to 29.97, but, you can manually type in 60.....or 59.997. Re-render then work with the re-rendered file at 29.97. Not sure this works, but, I tried it with a short clip and got pretty smooth slomo.

Trey Perrone April 14th, 2003 09:14 PM

the option to do that is grayed out on my clips...hmmm.... i tried a couple diff clips, original raw captures from a GL1 that havent been rendered or edited previously. tried to disable resample but it still didnt let me change that frame rate....any tips?

Bill Ravens April 14th, 2003 09:37 PM

ahhhh....be sure to select FILE in the upper right hand corner of the V4 window....then PROPERTIES. Don't right click the track to select PROPERTIES.

You want to set Project Properties, not track proper.ties

Trey Perrone April 14th, 2003 10:37 PM

ok i must be a complete imbecile bill....i was right clicking the file and it was grayed out. NOW i am clicking file properties, and i set the frame rate at 59.97 hit ok....playing back i see no difference in the file (should I?) i check the properties again it is still set for 59.97 FPS. the area below the preview pane says 720x480x32, 59.97. now i render out with best quality progressive.
now i open a new project and i goto import the file i jsut created, and the properties when i click on it are set 29.97 FPS for vid...i import the file and its apparent the change in the last project settings have not visibly changed anything...maybe i am missing something here. obviously i wasnt selecting the correct properties before, but now i am and its staying set for the project....?????


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