Proper procedure for anti-fogging liquid application

[TRIG]

[Quote; One of the most important things about a digital camera is to not expose it to the heat then place it in cooler water which creates condensation. I keep my camera/housing in a soft beverage cooler to insulate it. [/B][/QUOTE]

Another good tip, thanks Gilligan.



TRIG

 

[Eli]

Very interesting alternative, Dee. Definitely something that a guy would never have thought of! The Canon housings are very small and most dessicant packs wont fit, so a piece of a thin panty liner is a clever suggestion.
But will this make my camera tempermental once a month?

 

[Dee]

Eli once bubbled...
But will this make my camera tempermental once a month?

Not unless you put the tape on the wrong side! ut:

 

[Genesis]

Ports fog for the same reason anything else fogs - you have a surface that is below the dewpoint of the air on the other side. The moisture condenses on the surface.

The best way to avoid this is to have the dewpoint of the air in the housing be very low. Possible ways to do this include:

1. Load the camera in the housing in a hotel room or other air-conditioned space, where the dewpoint is very low compared to the temperature of the water. Do not open the case on the boat. No fog.

2. Purge the housing with scuba tank air (-50F dewpoint typically) before sealing it up, and insure there is no LIQUID water inside (e.g. splashed in) that can evaporate to raise the dewpoint.

IMHO the silica packs are waste. A pad as Dee described also won't absorb enough evaporated water to matter, but MIGHT help in the case of a minor liquid flood, in that it will trap the water rather than letting it slosh around. Of course in a REAL flood you're hosed.

I don't open the housing on the boat as a rule. If I have to for some reason, then I grab a tank and purge the housing with nice, dry scuba air before sealing it up. While I can't avoid ALL exchange while closing it once I do that, I take steps to avoid as much exchange as possible. Just be careful not to blow droplets of water into the housing while doing the purge! I have a "tilt valve" BC hose attachment that works real well for this (as well as blowing up baloons and similar things.)

 

[Eli]

Dee once bubbled...


Not unless you put the tape on the wrong side! ut:

ROTFLMAO!

 

[bdombrowski]

Genesis has it right.

It's all about dew point and making sure the air inside the housing never drops to a temperature that equals the dewpoint.

If you open your housing on the boat in the morning to load your camera, the humidity is likely very high, and the dewpoint is just a few degrees below the ambient air temp. When you close the housing, you trap this air in it, then take it down underwater where the temp is cooler. The trapped air cools to the dew-point.... fog!

To avoid this, the best rule of thumb is to never open the housing on the boat unless your inside an air-conditioned cabin. If you must open it outside, carefully try to fill the housing with dry SCUBA air before closing it, like Genesis suggested. Forget desiccants, maxi-pads, and mask defog. Those are band-aids and your are still exposing your camera to moisture which isn't good.

I once got into a bit of an argument with a guy on a live-aboard. This person believed he was a very experienced u/w photographer. He had an expensive housed SLR. He saw me loading my film and housing in the a/c cabin and said "You shouldn't do that in here, you'll get condensation inside your housing when you dive." I politely explained how that wasn't quite right. He didn't buy it and laughed at me.

Apparently, this guy failed high school physics. He was out in the moist salt-air with his N90 and assortment of Nikon AF lenses strewn about the deck. That was a couple of years ago. I'm betting his lenses have mold in them by now. Hopefully some poor sap on Ebay doesn't end up with them.

Regards,

Brian