>Published : 30th May 2005
>I've got a 16mm commercial shoot coming up where I have to fill a 16:9 frame with water that vibrates-ripples in time to a music track. This will be a background to post production graphics and strap lines. I have some time to experiment and will take full advantage of this luxury. Having spoken to the director briefly we came up with the idea of a large clear perspex tray filled with clear or coloured water sitting on a couple of speakers (out of frame) playing the music track, I'm thinking in terms of focusing on the surface with a narrow depth of field to lose any under water or bottom of tray aberrations.
>I will have time to experiment with the lighting, which I'm not to concerned about but, if anybody has an idea on this and the tray rig I would be happy for suggestions.
> I have to fill a 16:9 frame with water that vibrates-ripples in time to a >music track.
>A key thing will be the angle you aim the camera at the surface of the water. Looking across the surface at about 30 degrees from horizontal would work nicely; you'll end up making a surprisingly large tank/tray to avoid having a horizon line in frame mind you. Using a black coloured tank and/or water dyed dark blue/black will give a great reflectance if you then light a cyc/screen/20'x20'wind bag/whatever as a vertical element beyond the tank. Graduating the fall of light on your backing could enable you to create shape across the surface of the water.
>What kind of music track is it? Is there a regular bass drum pattern for instance? If the music is complex then certain sounds may create too many interference patterns and you'll end up with a right mess - it may be worth getting bass, treble, etc, on separate tracks (all with corresponding timecode) then shooting with a digislate and combining ripples in post. Similarly, positioning several speakers in different positions under the tray and getting separate channels playing through them would visually isolate sounds. Is there such a thing as a waterproof bass cone?
>If there is then you could have a fairly rigid bottom to the tank and cut circular holes right through and glue in speakers with silicane sealant. That way you'd vibrate the water in more specific places. Either way you'll probably get best results with only a few mm of water and adjust the volume to get the optimum ripple.
>It may be worth experimenting with using x2 speed music and a x2 fps. If the music is continuous throughout an alternative recording with sections of silence would allow some cessation of movement too.
>You'll rapidly get the ripples reflecting off the edge of the tank, outside of the edge of frame, and they'll mysteriously travel back into view; spoiling the effect of a limitless body of water. Shooting each beat or music cue as a separate element is the only safe way around this.
>Tom Townend wrote :
>It may be worth experimenting with using x2 speed music and a x2 fps.
>Talking to myself here (!) but it would be *very* nice to use an ArriSR3 and combine ripples with speed ramps. Since the speed of a ripple is pretty linear (close to the epicentre at least) it would look cool if you started a ripple at 100fps and then ramped down to 12fps or less a split second after 'detonation'.
>Just a thought like....
>I would pay a drummer or percussionist to hit the container to the rhythm that suits you. Depending on the beat the container is hit, I'm sure you will get a variety of patterns/looks. The speaker idea is good too, and you should be able to try it fairly easy.
>You might be able to drop a speaker right in the water there are speakers designed for pools, but you might just be able to seal a speaker in a plastic bag - let the air out the top so that the plastic bag sits right on the cone...
>...Just a thought...
>Don't use expensive speakers - I would go to a discount electronics store and look at some of the cheaper car stereo speakers for this sort of thing
>There are transducers made to turn solid objects into speakers that might bolt nicely to a tray of water.
>Then again, you could get a large speaker with a kevlar cone (or coat the cone with something water-resistant that you can spray on) and fill the cone with water, then fire up the speaker.
>Of course, you may have just build a large-bore, single-shot water canon...
>A couple of suggestions: Have several sizes and depths of water containers standing by. The reflections of the ripples off the side walls may make the water ripple more than you want.
>A wider container may work better as the ripples will decay and not reflect back into the primary ripples.
>You may also want to try the Jurassic Park trick. Get a bass piano string (at the bottom of the scale), secure it to the base of your container, and pluck it for some righteous ripples.
editor/Senior Doer of things
>Thank You gentlemen for your all your suggestions, which I will certainly will try.