Slow mo trick using your camcorder

Erk wrote on 10/18/2002, 11:53 AM

Like others who have posted, I've had trouble getting smooth slow motion using velocity envelopes when the camera is moving (eg, the camera is following someone walking). Resampling, "best" quality etc. often sometimes just doesn't help.

Here's a trick I've used as a workaround. On my Sony TR-720 Digital 8, there is a slow-mo button I've only found on the remote control, not on the camera itself. (On my remote, its the middle button on the bottom row). This gives you a standard slomo speed, maybe 1/2 speed.

What I discovered is that my camera will play this slo mo video out the firewire into my capture utility. First I capture the video at regular speed, make some preliminary cuts, print that to tape, then fly it back in in slo mo. Very clean. Usually saves time too, since a cuts-only, no-FX standard DV track will print to tape without rendering.

I can even hit the slow mo button for certain scenes, and then back to full speed, during regular capture, saving even more time.

This works for fast motion as well.

I don't know what other makes/models might have this feature. Probably pretty common.

Perhaps someone more technically knowledgeable can comment on the resolution/quality of the slow mo generated by the camera. It looks pretty good to my eyes. I gather that the camera is simply running the tape at a lower speed, and because DV is DV, each individual frame as it comes across the head is output at its full (original) resolution and quality.

G

Comments

HeeHee wrote on 10/18/2002, 1:10 PM

This sounds like a novel approach to slo mo issues, but a bit combersome.

Have you tried enabling the "Quantize to Frame" option in Vegas? This usually solves most slo mo related problems.

Erk wrote on 10/18/2002, 2:11 PM

Hee,

I always set Vegas to Quantize Frames, but it doesn't seem to help some of the problem slo mo scenes I mentioned.

G

salad wrote on 10/18/2002, 3:37 PM

I had used this technique of cap'ing DV in slo-mo, using Vidfactory 1.0.
Upon playback of the finished VHS I noticed BAD stuttering at those slo-mo parts...even with using the resample all video feature. I can't remember if I had tweaked the velocity during editing, but I found it was better for me to cap at standard playback, and apply the slo-mo in the program.
However, that was Vidfactory 1.0....
I would not be surprised to learn that cap'ing in slo-mo works just fine with VV3.0d.
The codec is much improved, as is the application.
Did I say "d"?

Let us know how it works out.

SonyDennis wrote on 10/18/2002, 10:10 PM

Erk:

Neat trick, I would have never guessed that would work.

I'm perplexed why you're not getting stellar slo-mo from Vegas. I do it all the time. Perhaps you could sent us one of your project files and we can render it with media we have here. DrDropout@SonicFoundry.com, reference this thread, and he'll forward it to me.

///d@

Erk wrote on 10/21/2002, 11:05 AM

SonicDennis,

Upon doublechecking, I think my slo-mo problems all involve footage that originated as film that was converted to Mpeg2, then to standard DV for editing in Vegas. Could there be a variable connected to film's slower frame rates that creates problems down the road? If so, perhaps there is a way to correct for this.

I'll try to isolate and example and send it on.

G

salad wrote on 10/21/2002, 2:18 PM

.....on that note......I have archived files originating from DVD, using codecs such as MS aviMPEG4, DVsoft, and Huffyuv. VV sometimes does not handle these formats very well when slo-mo is applied. My work-around was to render the sections that needed to be slowed down.....with just a little slo mo and checking the resample and reduce interlace flicker, then bring those renders back in as replacements, and apply the rest of the slo-mo I needed....applying the resample option again. You can try swapping field order also, as a test.

tinklady wrote on 10/21/2002, 6:45 PM

Thanks That is a very neat trick.

mm2k wrote on 10/21/2002, 11:04 PM

You really want the slo-mo that you might have seen in music videos that looks like 60fps ? It cost about 3 grand for the software mainly pros use it. I have not once seen anyone in any VV forum mention it, no disrespect, but all you VV user need to do more homework when involving youself in the world of video editing & f/x. And now the software name, "Retimer" by Realviz at www.realviz.com This software makes slow motion flow as smooth as pouring honey. Slow mo is pretty good in VV but no program cam compete with this that I have found. One does come close, its called Twixtor by www.revisionfx.com If you find anything in this department please post it, 3K is a bit steep.

SonyDennis wrote on 10/22/2002, 2:02 PM

Erk:

Indeed, if your video was telecined from film, then your slo-mo will not be ideal. You should first do inverse-telecine (using Virtual Dub or something) to get back the orignial 24 fps material, then slo-mo that. Even then, you've only got 24 fps to work with, which is not nearly as good as the 60 fields per second that Vegas uses from interlaced video for slo-mo.

///d@

Erk wrote on 10/22/2002, 3:04 PM

SonicDennis,

Thanks for that, I think that solves some mysteries. I don't think I've had any slomo problems with anything but that "telecined" footage (a new word for me....)

G