i just got a housing to use with my canon hv20. my question is, is it wise to use compressed air to fill the housing with prior to closing it? i wouldn't pressurize the housing, just blow the air into the cracked door, and then seal it. the atmosphere here is quite warm and muggy here (90F+, +80% humidity), and the the water i'm diving in is fairly cold (68F). the canned air i'd be using is CO2 from one of those bike tire inflators. my only concern is the cam might function differently with a different air mix in the housing? anyone have any thoughts on this?

Hi Austin,

There really isn't any reason I can see to do this. In fact you are likely to open yourself up to all kind of problem. The cold air from the can will hit the warm sides of the housing and condense (if the housing is metal) and you will introduce moisture into a place that by default needs to keep very fry. I regularly take a large housing and camera from 35 degrees C where it has been baking on a boat down to 18 degrees C without any problems. I strap a large bag of silica dessicant inside the housing to absorb any moisture. Just put the camera in the housing without any messing, be safe and enjoy yourself.

Good luck,

James

that's good to know, i'm going to be shooting out in a hot and muggy swamp, with limited/no access to a conditioned environ, and i read about people loading their cams in their cars with full a/c running. and i figured i could use the compressed air to replace the cold air from the car...

I shot a feature ddocumentary in the mangrove swamps here in Mozambique. We had only had one camera and the working day involved putting the camera in and out of the housing several times a day. We came up against a issues which I can share.
- Moisture in the casing. Hot and muggy swamps led to hot and muggy people with sweaty hands. In the beginning we had issues with the front port steaming up this was mainly solved with the big bags off silica gel, I taped one to the camera handle.
- There were a lot of bugs in the mangroves and a few times I ended up with a Mosquito in the housing. This was always discovered during a shot as it landed on the front lens and led on to a mad rush to remove the offending bug so that we could continue with the work. This would be a good reason to load your housing in a 'sterile' environment.

The main thing overall is to avoid rapid changes in temperature so that a 'chilled' camera into a hot environment, or chilling a camera in a hot environment I personally would avoid. Best scenario would be to have two cameras, one left inside the housing and one for your topside shots. If this is not possible then take care putting the camera in the box.

Cheers,

James

Which housing are you using for the HV20?

i got the sony spk-hcb, $100 on amazon... i just put the remote in a bag, and use it to conrol the cam when it's in the housing.

http://file.meyersproduction.com/hv20/hv20%20housing/