Shooting in a Swimming Pool

[Wandering Ear]

Mark, I'd suggest always running the boom mic, and possibly having a room mic running as well, that way you give post production the option of tailoring the amount of reverb as much as possible, especially when running lavs. It will help them match the shots where you can't get in very close with the cu's.

Thing brings me to something I've thought about doing for quite a while, but haven't broached the subject much. I was going to make it it's own thread someday, but here goes.

If post is on board, you could also record an impulse response (popping a baloon works quite well). This would allow post to model the room with a convolution reverb, and make matching the different shots in the room easier. Does anyone regularly do this?

K

[Simon Hayter]

'Thing brings me to something I've thought about doing for quite a while, but haven't broached the subject much. I was going to make it it's own thread someday, but here goes.

If post is on board, you could also record an impulse response (popping a baloon works quite well). This would allow post to model the room with a convolution reverb, and make matching the different shots in the room easier. Does anyone regularly do this?'

Interesting, I've never heard of this before but I'm going to suggest it to my post department. I often have to shoot in rooms with a lot of reverb. Thanks

Simon

[Marco Lopez]

'Thing brings me to something I've thought about doing for quite a while, but haven't broached the subject much. I was going to make it it's own thread someday, but here goes.

If post is on board, you could also record an impulse response (popping a baloon works quite well). This would allow post to model the room with a convolution reverb, and make matching the different shots in the room easier. Does anyone regularly do this?'

Interesting, I've never heard of this before but I'm going to suggest it to my post department. I often have to shoot in rooms with a lot of reverb. Thanks

Simon

Actually Altiverb gives you this option. You record an impulse on set ( a clapboard would do) and then import the file in altiverbs plugin and use that impulse to match ADR with the on set sound.

[Wandering Ear]

Most convolution reverbs will give you the ability to use your own impulses. I've been able to record a couple when I'm in a great large space, but so far I haven't been on a production where it was used in post. It seems like it could be the evolution of room tone. Now it's room tone & impulse.

[taylormadeaudio]

Correct. The speed of sound in the medium won't change the frequency. The speed of the source or the observer relative to one another will alter the frequency (Doppler effect) but that isn't the case here. If you want to confirm this, put the post end of a tuning fork in water and listen to the sound in the water. It will stay the same. What is happening in the swimming pool case is that the water and/or hydrophone is emphasizing the high frequencies and attenuating the low frequencies thereby shifting the perceived "noise" to a higher frequency average.

Best,

Larry F

Lectro

I started to reply something to this effect and then figured, no, wait -- someone else who is far more versed at explaining these things than I am will inevitably chime in. Thank you Larry : )

~tt

[taylormadeaudio]

Most convolution reverbs will give you the ability to use your own impulses. I've been able to record a couple when I'm in a great large space, but so far I haven't been on a production where it was used in post. It seems like it could be the evolution of room tone. Now it's room tone & impulse.

I always thought it was fairly common practice.

~tt

[studiomprd]

I was going to say, "yeah, that's what ||I meant"

or "Thanks Larry",but

that wouldn't further the thread

[taylormadeaudio]

It's ok Senator, you can say it anyway

~tt

[studiomprd]

" The speed of sound in the medium won't change the frequency. The speed of the source or the observer relative to one another will alter the frequency (Doppler effect) but that isn't the case here... "

That's what I meant...

Thanks Larry!

[Mark Andrews]

I would like to give a big thank you to everyone who contributed to this thread. I returned home at 9am this morning after our second and final night in the swimming pool, and I am confident that both the sound and images captured by the crew should allow the creation of a beautiful film in the edit.

From my side of things, the pool was perhaps not as difficult as expected, mostly due to the very accommodating nature of the pool staff. We did lower the level of the water to below the drainage area, and combined with shutting off the noisy pumps it did the trick.

The biggest issue was when we were doing the underwater shots. As the pool was not crystal clear underwater it appeared very murky on camera, so the pool staff added extra chlorine to clear it up somewhat. That meant the filters had to be left on, or else the risk of air bubbles jamming up the pools system was too high (which would have resulted in the shoot being entirely cancelled). So we had to cope with having the filters running, which was akin to a noisy air-con unit under the water. They can probably minimise it a bit in post, but still not ideal.

I came up with a simple way around the non-waterproof lavs by not using them. In the end, we got the dialog we needed with an MKH50 on the boom (and ran a few wild lines for extra coverage). When he was swimming along we had the hydrophone underwater and the MKH50 in a basket following along over him. I had a Sennheiser ME66 as a room mic at the back running just about all the time, just to provide extra options.

For the crowd scene we used 4 mics - the MKH50 on the boom above the crowd. The ME66 at the back of the room, and two cos-11's on radios planted as a concealed, spaced pair. It was far from exactly accurate, but I was happy with the results.

Overall I learnt I love the MKH50. Great mic. I also learnt a little about hydrophones, and about staying awake throughout the night.

~Mark.

[Jim Feeley]

Thanks for the follow-up report. Glad everything went well.