variable speed sound sync

[Zak Mulligan]

Hi all!

 

This is my first post here and I'd like to thank you all in advance for the sound advice (pun intended).

 

I'm shooting a music video in a couple of months and have been kicking around an interesting idea for an effect. I'd like to do in camera speed ramps while the artist lip syncs to the song. This could be ramping anywhere from 5fps to 60fps up and down for different parts of the song. In order to do this I need to have a variable speed playback that's synched to the camera for her to lip sync to.

 

So my questions are:

 

1) Could I do this in a ?low tech? manner using a governor motor or variable AC motor hooked to a dimmer that also controls a tape deck - all plugged into the same AC outlet? If so what equipment might I use? Would I need to use an older camera with an older motor? FYI ? This is a 16mm/S16mm shoot.

 

2) Or do I have to use an Arri 435? If so how would I sync the audio? To get the sound to ramp (speed up and slow down) what sort of device could be used?

 

I don?t think the budget would allow for a 35mm shoot, but I?m interested in anyway this could be accomplished.

 

 

THANKS!

Zak

[Guest beanpat]

Hi all!

 

This is my first post here and I'd like to thank you all in advance for the sound advice (pun intended).

 

I'm shooting a music video in a couple of months and have been kicking around an interesting idea for an effect. I'd like to do in camera speed ramps while the artist lip syncs to the song. This could be ramping anywhere from 5fps to 60fps up and down for different parts of the song. In order to do this I need to have a variable speed playback that's synched to the camera for her to lip sync to.

 

So my questions are:

 

1) Could I do this in a ?low tech? manner using a governor motor or variable AC motor hooked to a dimmer that also controls a tape deck - all plugged into the same AC outlet? If so what equipment might I use? Would I need to use an older camera with an older motor? FYI ? This is a 16mm/S16mm shoot.

 

2) Or do I have to use an Arri 435? If so how would I sync the audio? To get the sound to ramp (speed up and slow down) what sort of device could be used?

 

I don?t think the budget would allow for a 35mm shoot, but I?m interested in anyway this could be accomplished.

THANKS!

Zak

 

first off, doing this up 60fps is probably not realistic. I don't know which 16mm cameras can ramp and control shutter angle automatically. I'm assuming you know that the camera has to have this ability? I know the 35mm panavision cameras can and probably thier 16mm version can as well. anyway it most likely will require a camera that can send a timecode signal or pilot signal to the playback device. which will have to be hard drive based or reel to reel. dat can only change speed by a small percentage. have you figured out how a fast the average person can lip sync? that would be a good starting point I think.

sounds interesting though.

 

Patrick

[Brad Grimmett]

2) Or do I have to use an Arri 435? If so how would I sync the audio? To get the sound to ramp (speed up and slow down) what sort of device could be used?

 

I don?t think the budget would allow for a 35mm shoot, but I?m interested in anyway this could be accomplished.

THANKS!

Zak

An SR3 can do the ramps no problem. I've done it before with this camera. The sound may be tough, but I don't know. 60fps should be okay for the musicians. I've done up to that speed before and it was OK. We tried 72fps once on an already fast song and it was comical. The drummer just about passed out halfway through the song. But 48fps was already pushing it because of the speed of the song. Good luck.

[Luke Prendergast]

If it's a mathematically simple speed ramp, eg. linear, then shooting at your max fps and constructing the ramp and sync in non-linear post would be very easy.

[Zak Mulligan]

I don't think the SR3 has an elctronic shutter, I think I would have to go 35mm for that option. I've been thinking of keeping the ramping to between 12fps-48fps, this way I only have a 1 stop range of over and under exposure. I can do a supervised transfer to HD and correct the exposure before it gets to tape. I really need to test all this but right now I'm most concered with figuring out a way to keep the playback in sync with the camera. I'm going to call some sound guys I know and see what they have to say. Thank you for your comments... has anyone tried synching with AC? I thought a lo-fi way would be to use a dimmer that controls a tape deck and an older AC motor. Anybody think this is even possible? Any and all suggestions are welcome :D

 

Cheers

Zak Mulligan

 

If it's a mathematically simple speed ramp, eg. linear, then shooting at your max fps and constructing the ramp and sync in non-linear post would be very easy.

 

 

If the playback is set for 48fps on set and I remove frames in post (I assume this is what you mean) wouldn't the sync be lost? Wouldn't I have to have the audio ramps established and played back while shooting at maximum frame rate? That seems like it could work.

[Marty Hamrick]

f. I don't know which 16mm cameras can ramp and control shutter angle automatically. I'm assuming you know that the camera has to have this ability?

 

Patrick

 

 

I'm assuming the shutter angle control is to adjust for the change in exposure which accompanies speed changes?You could do the same thing by changing the iris setting as you ramp up or down,but that would alter the DoF.

 

I did a shot like this years ago with a Beaulieu R16.It was a ramp down from 24 fps to 2 fps and back to 24.Did it manually turning the meter knob on the side of the camera at the same time as adjusting the fps rate.It worked,DoF wasn't an issue on that as the shot was with a super wide lens.