Go Pro Fogging

[Marty Cerven]

I personaly wouldnt use any product on the lens, even if it doesnt damage the lens it may effect the image quality, using desiccant will do the job well without the need for this I think.

The only product I use is spit when using the camera just above the surface, if you spit on the lens then dip in the water this keeps water from beading on the outside lens. Obviously this is only an issue above the water and will do nothing once you take the camera below the surface.

 

[TravisD]

There's more than one way to skin this cat, but my experience last year on a liveaboard was that I had no fogging issues. I sealed up the camera in my room each time, blowing air directly from the a/c unit into the housing as I closed it up.

Another thing to keep in mind - a lot of the reports on "fogging" may actually be the dome lens issue. Some other folks on my trip had the camera and reported fogging, but looking at it, it really seems to be the focus issue.

 

[krukster86]

I have had the inside of the GoPro U/W housing fog up, but it had no effect on the video.

 

[aj555]

Just buy the $15 anti-fog inserts from gopro. Problem solved

 

[cowdog77]

Nice post.....succinct and to the point, much appreciated!

 

[danpass]

Use the GP anti fog inserts as regular dessicant packs won't fit (unless you use the fat back and stuff it with dessicant packs instead of LCD, batterypac, etc)

and otherwise do the air conditioned room thing.

The Hero2 generates heat to manage battery life. I've tested the dual battery setup in the freezer (minus 20F) recording the face of a G-Shock watch timer; 3.5hrs of life

but it fogs up, even with the GP strips, a/c room, etc and irritatingly it is ONLY the inside of the dome lens that fogs ... sumbitch.

But I've run the Dive Housing rig in 82F water without GP strips for an hour of continuous recording without issue but in Cozumel (with the dome housing) at the Dolphin experience it fogged up. Strangely enough I stopped the recording for about 5min, the fog cleared and when I started it up again (continuing in the same environment) it did not fog up for the rest of the event.

It'll be nice to figure out the magic prep combination lol

 

[archiebald]

The Hero2 generates heat to manage battery life. I've tested the dual battery setup in the freezer (minus 20F) recording the face of a G-Shock watch timer; 3.5hrs of life

Sorry but this logic is back to front.

As with all batteries, the Li-Ion batteries in a GoPro lose efficiency at low temperatures (They also lose efficency at very high temperatures as well but not within the range we would be interested)

The reason why the life is shortend in the freezer, is simply due to loss of efficency at low temperatures.

The reason why the battery gets warm during use is due to a chemical reaction taking place during discharge. To a certain extent, this will help to prolong the life in very cold conditions.

The reason why the camera gets warm is because the electronics are doing work and heat is being generated.

So, the generated heat is just a by-product of being used. It just happens that happily for us, that heat can also improve the battery lif a little in cold conditions.

but it fogs up, even with the GP strips, a/c room, etc and irritatingly it is ONLY the inside of the dome lens that fogs ... sumbitch.

Normal domestic freezers work at -18C (0degF). In order to prevent condensation inside the casing under these conditions, you would need to get the dewpoint of the air inside to lower than -18C before you sealed your camera in. I'm pretty sure that even when in perfect condition, the desiccant pads will not be able to pull sufficient moisture out of the air to prevent fogging at this level.
The reason why the dome lens fogs first is because it is glass and the rest of the body is polycarbonate. As glass has a higher conductivity of heat, this is the area that gets cold first.

If what you said about your freezer (-20F = -28C) is correct then your air dryness before starting would need to be even lower in order to prevent fogging.

I work in the plastics industry where we routinely have to dry raw materials to moisture levels below 0.005% using air at dewpoints of between -20C and -40C. Believe me when I tell you that there is nothing in your house that can achieve this level of dryness. Air conditioners, hair dryers etc have no chance. It would require an industrial desiccant dryer system.

But I've run the Dive Housing rig in 82F water without GP strips for an hour of continuous recording without issue...

82F = 27C. So as long as the dewpoint of the air was less than 27C when you closed the case, then the result you got was to be expected. Maybe you closed the case in your hotel room?

...but in Cozumel (with the dome housing) at the Dolphin experience it fogged up.

Maybe your conditions at the time of closing the case were worse, or the temperature of the water was cooler.

Strangely enough I stopped the recording for about 5min, the fog cleared and when I started it up again (continuing in the same environment) it did not fog up for the rest of the event.

May have been coincidence, difficult to say

It'll be nice to figure out the magic prep combination lol

I have already posted a detailed list of tips further up in this topic that may be of some help. Once you understand what "dewpoint temperature" is, then the magic just becomes science.
-------------

As an interesting aside, when air is compressed it is essential to get LOTS of moisture out. This is because when you compress even reasonably dry air with just a few water molecules in it, the water molecules get squeezed up against each other and very easily condense. All industrial air systems use air dryers after the compressor to remove the moisture. If you don't, you end up with liquid water in pipelines and operation valves. This creates MAJOR maintenance issues. In addition, as compressed air re-expands, it cools so any water present may turn to ice and freeze, blocking valves and regulators.

Now think about a scuba tank and your regulator. Any moisture present in the air would be a very bad thing indeed.

So based on this, fire departments work on a required dewpoint specification of -54C (-63F). I am not sure what scuba air is specced to, but I imagine it will be very similar. Source

This is the reason why the persons above who have reported using a dose of scuba air to purge out their camera cases have reported very good results. They are able to get their casing down to very low dewpoints before snapping them closed.

 

[g550driver]

An alternative to the anti-fogging strips is to use strips cut from a shammy.. (SHAMWOW).. These can be had in 10x15 sheets for $5.00 or so (on EBay)... Enough to make a gazillion anti-fog strips.. LOL (well, not quite a gazillion, but quite a few)

 

[danpass]

Sorry but this logic is back to front.

As with all batteries, the Li-Ion batteries in a GoPro lose efficiency at low temperatures (They also lose efficency at very high temperatures as well but not within the range we would be interested)

The reason why the life is shortend in the freezer, is simply due to loss of efficency at low temperatures.
......

http://gopro.com/cameras/hd-hero2-motorsports-edition/#features

Hence the reason for the heater. Battery life would have been less in the freezer without the warmer.

 

[flareside]

Hence the reason for the heater....

There is no heater. The "Integrated Battery Warmer" is the main image processing chip and it naturally runs very warm. The battery warmer was not something they intentionally added to keep the battery warm, it was already there. (But hey, why not make a marketing gimmick out it if you can.)