GoPro fogging - this is ridiculous!

[RickI]

I am usually in subtropical areas with elevated outdoor temperature and humidity and air conditioned interior spaces all over. Desiccant strips can saturate in hours at times and can become largely useless with minimal warning, in my area. I trashed some unique inter-island aerial footage in the Bahamas shot from a plane's stabilizer learning this hard fact four years ago. For that reason and other negative experiences, I no longer use the desiccant strips.

Paper towel sections work here, there is no theory about it, just several years and tens of thousands of clean images to support it, in my area. I have also used it for short stints in the mountains in snow with success. Storing and sealing the housings in AC, means not even bothering to change the paper towel sections for weeks or months, unless they get wet.

Desiccant strips accumulate water and don't readily dry out in AC, they need to be baked dry on a regular basis or changed out. If they are exposed to high humidity, they can saturate rapidly. Paper towel sections do dry in AC with no baking required or really anything else. People in temperate areas may have different experiences, so use what works in your area.

Also, heating of the housing interior will cause condensation at times, this is a fact again backed up by lots of practical experience above, on and under the water. It is identified as a factor in analysis of fogging of housed gear by many manufacturers. Are you assuming constant pressure within the housing? With heating, internal housing pressure will increase impacting the dew point.

For folks theorizing about going with replacement gases, have at it. Underwater housings have been pressurized with nitrogen for about 60 years and in other cases, vacuums have been pulled for at least the same time frame. Both measures will impact fogging and other problems but to do it right, means installing a valve.

[gbgreen59]

His math using 30C at 80% RH = DP 27 C does not equate to 40C @ 60% RH. He pulled those numbers out of the air.

Once the housing is closed, whatever mass of water (in its vapour phase) is contained within the housing is fixed. Once the ambient interior air contacts the glass lens (best thermoconductor) that is at the dew point, it will condense. Regardless of the internal housing case temp being raised by the battery discharging.

The paper towel is cute, but unless your paper towel has been dried, it contains water at the same ratio as the air you stored the roll of paper towels in.

Here is THE ULTIMATE solution:

1. Squirt a bit of canned inert gas (like the wine preserver) into the housing with the door facing up and the lens down. You will have SUPER DRY air/gas in the housing. The dew point will be close to the freezing point of water. You will not get condensation.

2. Use the GoPro desiccant strips also. They will address any possible water that MAY be (hypothetically) present on interior surfaces of the camera board, battery etc during your session.


Alternately, you can get close using the "Air Conditioner Fill" method.

Or, you can put the desiccant strips (not toilet paper or paper towel unless it has been super dried in an ELECTRIC oven. into the housing and close it up in hour or two ahead of your session. This will allow the strips to absorb any of the water vapour in the housing.

Interesting and makes pretty good sense. What I do for water and snow is I close the GoPro housing before I leave and it has the misture strips inside. It may be 1 or more hours before I actually take it out and use it. Maybe that is why I don't have fogging. The temperature is stable and the strips have had over an hour to absorb moisture.

[flyrob]

Rick

You are a smart guy who contributes immensely to kiting in so many ways. And you have a lot of credibility.

But in this case, your anecdotal "this works for me" and dismiss and co-mingle other more science based practices as all or nothing or "theoretical" is not helpful.

Take your affection for paper towels and dismissal of desiccant strips.

Dessicant strips have a much higher capacity for holding water/moisture than paper towels.

Period.

Otherwise the electronics industry, the drug industry etc etc would use "Rick's Paper Towels" instead of expensive silica gel or desiccant papers to reduce the relative humidity within their packaging.

As to dismissing desiccant strips that are not correctly stored and then saying your paper towels are better. Either of these materials will equalize to the same relative humidity as the environment in which they are stored. The desiccant strips can hold MORE water/water vapour than paper towels.

Dessicant strips are so cheap, reusable, easily recharged and stored correctly as to be a non-issue. Bake them in a toaster oven at 250F for an hour or so and store them in a little glass spice bottle (optimum) or even in a little zip lock bag and you will have a much superior and more effective desiccant to keep your housing free of condensation.


As to using an inert gas. You don't have to employ fancy valves "pull vacuums" etc to "do it right". In fact, those measures would complicate and introduce more risks.

By displacing some of the ambient air with a drier gas, you WILL reduce the dew point and bring it down below the point at which it would condense on the lens.

I ride and use my GoPro in Lake Ontario and the Great Lakes and in the DR, Florida etc in varying conditions. Since I started using the wine preserver gas and the desiccant strips I have NEVER had any fogging at all. Yet the other guys with toilet paper, diaper material, rice etc often get fogged up.

[RickI]

Use what you would like and good luck. Ignore long practical experience of what works and what does not in subtropical areas over years of use in favor of theory if that is your choice. It is curious but so be it.

The following is just a small sample of images above, under the water and in other areas but look for evidence of fogging. Water spotting is a different problem and one I am still working on through various means.

http://www.pinterest.com/flkitesurfer/g ... otography/

[flyrob]

I'm just a little torn on which model to get: black, silver or white. It seems that the black is quite a bit better in many regards, but not sure if I need such precision. It's my first action camera so not sure I need the top of the line, but if it's only $100 more might just pull the trigger on the black.

I have held off on the new Black model as I have heard that its power consumption is much higher than the others and makes for really short recording sessions.

As most of our use is for posting on Vimeo (at best) the ultra high resolution of the Black is lost and it really slows down editing and rendering. And unless you are using a really high powered multi-core computer with SSD's etc it can become a pain in the ass! Ultimately, the native high resolution is compressed in editing and extrapolated in rendering and the compressed and lower resolution is worse than if you had have just recorded and edited in the resolution you intend your end production to be viewed in.

[flyrob]

Use what you would like and good luck. Ignore long practical experience of what works and what does not in subtropical areas over years of use in favor of theory if that is your choice. It is curious but so be it.

I am not ignoring anything. I have no doubt that your unique combination of practices is effective for you and your experiences.

My practices are not theory. They work for me and they will work for anyone. I am simply using science to explain why they work.


This kind of discussion is like herbal medicine or anti-vaccine advocates dismissing the science of modern medicine.

[nicor]

I'm just a little torn on which model to get: black, silver or white. It seems that the black is quite a bit better in many regards, but not sure if I need such precision. It's my first action camera so not sure I need the top of the line, but if it's only $100 more might just pull the trigger on the black.

I have held off on the new Black model as I have heard that its power consumption is much higher than the others and makes for really short recording sessions.

As most of our use is for posting on Vimeo (at best) the ultra high resolution of the Black is lost and it really slows down editing and rendering. And unless you are using a really high powered multi-core computer with SSD's etc it can become a pain in the ass! Ultimately, the native high resolution is compressed in editing and extrapolated in rendering and the compressed and lower resolution is worse than if you had have just recorded and edited in the resolution you intend your end production to be viewed in.

Thanks! this is very useful I just needed nudge in the right direction.

I have an Mac Air, and i'm not very tech savvy. Just looking for solid camera to capture good solid shots that I can create a short vid and maybe post later on.

I suppose I'll go with the Hero 3+ Silver unless I find even that's too much.