Filming in a sauna

Hi,

I have a job coming up where we need to film in a sauna.  Has anyone ever done this successfully with an underwater housing to protect the camera? 

Any ideas would be great. 

Thanks,

Doug

Sounds, errr, intriguing! 

An underwater housing would protect the camera for sure. You might have to do a little experimentation with whether you get fogging inside the lens port. If you use an aluminium housing - rather than acrylic - i wouldn't think that a problem. 

You'd be filming wide-angle right?

Thanks Tim.  I would be mixing up the focal lengths so using a zoom to not have to open the housing.  

Ok, hmmm, I can't think of any reason why it would not work.

Normally, for wide-angle underwater, the lens focuses on a virtual image of the subject - not the actual subject. This can cause difficulties getting the edges sharp because of the curvature of the wide-angle port and the lens being incapable of providing sufficient depth of field.

But if you are photographing above water, the lens doesn't use a virtual image to focus - but the actual. So "soft edges" should not be an issue with wide-angle.

I'm sure others will chip-in too.......

Fogging inside is unlikely to be a problem as the housing is getting hotter - heat does not cause housings to fog internally if they are dry inside.  The cold water causes water to condense on the optics as they cool off.

the problem would likely be that the dome would fog externally and keep doing it till it warmed up - you might try scuba mask anti-fog on the outside and keep it wet - similar to what you do when shooting in the surf. 

I'd also vacuum the housing as the air inside will want to expand as it warms - a flat  back housing is likely to allow air inside to escape then when it cools off it will be hard to open.   If you apply vacuum the internal pressure should stay lower than external pressure as it warms up.

Housings are not really designed with internal pressure in mind and it may create some issues depending on the exact housing design.  Housings generally rely on external pressure to keep everything closed - not their latches! and if you get higher pressure inside it will put strain on the latches/bayonets etc.

I would think internal fogging would be your biggest problem. When you install the camera into the housing make sure you are in a room with dry air (like in an air conditioned room). Maybe put a couple of silica gel packs in the housing. I have seen my dome port fog when I accidentally left it in the sun on the boat, but the fogging went away pretty quickly once I got it underwater. I live in an extremely humid climate. 

58 minutes ago, UWPics said:

I would think internal fogging would be your biggest problem. When you install the camera into the housing make sure you are in a room with dry air (like in an air conditioned room). Maybe put a couple of silica gel packs in the housing. I have seen my dome port fog when I accidentally left it in the sun on the boat, but the fogging went away pretty quickly once I got it underwater. I live in an extremely humid climate. 

 

Internal fogging after leaving the housing in the sun only occurs if there are water droplets inside the housing that can evaporate then find somewhere colder (the port glass usually) to condense.  These droplets might be hiding behind the o-ring in the groove for example.  If they are inside the o-ring when the housing is closed they can evaporate if the temperature goes up.

If it's already dry inside - no liquid water-  it can't occur from heating.  Taking a housing full of humid air underwater is a different scenario.  The port glass cools off to less than the dew point inside the housing and you have fog.  For condensation to occur there is one requirement - surface must be colder than the dew point of the air.  The dew point is the temperature where water starts to condense due to the air being saturated with water - it can't hold any more water.

Taking a housing into a sauna the biggest problem is condensation on the outside as the housing is cooler than the dewpoint of the air inside the sauna.

1 hour ago, ChrisRoss said:

Taking a housing full of humid air underwater is a different scenario.  The port glass cools off to less than the dew point inside the housing and you have fog.  For condensation to occur there is one requirement - surface must be colder than the dew point of the air.  The dew point is the temperature where water starts to condense due to the air being saturated with water - it can't hold any more water.

Yes, I believe you are right Chris. The fogging may have occurred after I took the housing underwater from sitting in the sun, but in any case it cleared quickly. I have made a habit of assembling my rig in an air conditioned room (if possible), and not letting it sit in the sun for too long.

Chris,

Thank you so much.  This is very helpful and will now lead me to study up on everything you discussed.  I love that I'm always learning from these communities.

4 hours ago, UWPics said:

Yes, I believe you are right Chris. The fogging may have occurred after I took the housing underwater from sitting in the sun, but in any case it cleared quickly. I have made a habit of assembling my rig in an air conditioned room (if possible), and not letting it sit in the sun for too long.

Good habit to get into - the sun can only cause fogging internally if there is water to vaporise - still a good idea to keep the housing out of the sun though.

I haven't worked in a sauna, so this is interpolated from other experiences. Summary of my thoughts - some already covered above.

A housed system will be heavy compared to a bare camera. Not such an issue on a tripod, but soon becomes tiring if hand-holding.

You don't need pressure proof. Just moisture resistant. A compact such as a TG6 or an action cam / Go Pro may have good enough quality, be more convenient to work with, and be a lot cheaper than buying a housing (unless you already have a housed system)

For a housed system, to minimise fogging inside, assemble in dry conditions. Add a small sachet of desiccant inside the housing. As already noted, unlikely to be an issue if its hotter outside.

Leave the camera or housing in the operating environment for a few hours for temperature to equalize to cut down on internal or external fogging.

Flat or dome port on a housing won't make a difference to focus in the air. You won't need any correction diopter on the lens for a dome.

Possibly a dumb question, but does the sauna have to be hot?  Spray bottles can simulate sweat and there’s no visible steam in a sauna anyway.  

Following up from troporobo's comment, I guess the question in my mind is:

Does Kyanos mean a sauna or a steamroom? 

Both are hot, one is dry, the other isn't. Thinking different problems...

I'm guessing that most directors would shoot a sauna 'cold' and either add steam in post or use some sort of haze. Probably would be a much cheaper option if you don't already have a housing, you can buy haze in a spray can for pretty cheap.

Canned Haze?!??! Love it!!!

Does it come in Purple?

9 hours ago, TimG said:

Canned Haze?!??! Love it!!!

Does it come in Purple?

ha ha ha ha ha good one Tim :-)