Focusing noise with Sony RX100 M2 in Recsea housing?

[benignor]

Hi, I have noted that recent videos taken underwater with this setup have an annoying, sometimes very loud, vibrating noise. This happens only underwater. Example below. I think I can hear a very faint similar noise in UW video taken about 1 week prior with the same rig, but even that i'm not so sure about.
[video=youtube_share;oPDkhMZsTiQ]http://youtu.be/oPDkhMZsTiQ[/video]

I just took a clip with the camera out of the housing -no noise. Immediately after, I put the camera in the housing, put it in my sink - noise.
[video=youtube_share;udm4XsTYgOw]http://youtu.be/udm4XsTYgOw[/video]

What could possibly be causing this behavior?

 

[Incident]

That is the sound of the small motors used to drive the focusing mechanism. The reason I would suspect you hear it in the housing but not outside the housing is that the sound is both trapped in the housing with the camera, and that perhaps the vibration it causes is also being captured.

Even big DSLRs when used in video mode can exhibit this problem.

Can you turn off the mic on the camera when used to make a video?

 

[Interceptor121]

Incident is correct. It is a problem of all cameras capable of continuous focus in video mode. You could of course work with manual focus but that may prove an issue unless you have a wide angle lens and your subjects are pretty far
I put audio recording to OFF in all my clips and actually I don't recall one dive I have done where I missed the audio track

 

[benignor]

Thank you all. I thought that was the case, but wasn't sure. It seems to be louder in some clips than in others, but looking at some examples, it seems to be exactly as you are suggesting: the ones where the noise is much more muted seem to be ones where I was using a wide angle and the subjects were far away, which presumably meant the focusing motors didn't have to work constantly.

Thanks!

Incident is correct. It is a problem of all cameras capable of continuous focus in video mode. You could of course work with manual focus but that may prove an issue unless you have a wide angle lens and your subjects are pretty far
I put audio recording to OFF in all my clips and actually I don't recall one dive I have done where I missed the audio track

 

[KeithG]

this is why my old school amphibico video housings all had an external hydrophone. if you forgot to plug it onto the camera then you got lots of tape drive motor noise (and even worse, mechanical switch clicks on my first housing).

with the hydrophone there was only your breathing, pops and clicks from other divers bubbles and the odd grunting /squeal from the fish. catching a parrotfish chomping into the reef provided a startling crunch.

no need for a music track if you have a hydrophone.

 

[EL Pistoffo]

There are many camera that will pick up focus noise even topside. In camera mics have that inherent issue.