Ike housings and fogging

[vkalia 1]

What is the propensity of Ike housings to fog up when the internal flash is used? Do they fog up about the same as smaller, manufacturer-made housings or does the greater air volume inside mean that they fog less?

 

I find silica gel packs, while useful, rarely work super-reliably. So all else being the same, if the Ike housings do tend to fog when used with the internal flash, I'm going to get a cable-fired strobe. Otherwise, optical-cable firing.

 

Thx,

Vandit

[Islandbound 1]

I have never had the Ikelite G7 housing fog up, ever. Where I live it is over 90 degrees with the same in humidity almost year round. The water is well over 85 degrees in the upper 10 feet and can drop into the 70s below that easily.

[vkalia 1]

Thanks, IB. That's good to know - I am in a similar location myself, so I reckon I'd probably have a similar experience.

 

So a fiber-optic cable may indeed be an option for me.

 

Vandit

[davephdv 0]

It seems that most fogging up is due to taking the housing into air conditioned rooms and then out into hot and humid environments. Plastic domes or ports due seem more susceptible to fogging than glass ones. The manufacture of the housing doesn't seem to matter.

[jlyle 8]

It seems that most fogging up is due to taking the housing into air conditioned rooms and then out into hot and humid environments. Plastic domes or ports due seem more susceptible to fogging than glass ones. The manufacture of the housing doesn't seem to matter.

 

It isn't the housing, it's the camera. When you move a camera from an A/C room out into hot/humid air, condensation will occur, inside the camera. This hidden moisture will cause fogging when the camera is sealed into a housing and warmed by the internal flash. It's a good idea to keep your camera in a sealed plastic bag and let it thermally equilibrate before using it in hot/humid climates. Where there is no moisture, there can be no fogging.

 

The acrylic lens ports don't tend to fog as much as glass ports, so this is less of an issue with Ikelite housings.

 

1. Avoid hidden condensation inside the camera by using the sealed plastic bag trick, above.

2. Put a couple of desiccant packs inside the housing.

3. Seal the housing in an A/C room.

[4. A panty-liner in the bottom of the housing is cheap insurance against a minor leak!]

[DesertEagle 2]

jlyle's advice is excellent.

 

Ikelite's housings are typiclly less prone to fogging problems than the small name-banded housings. They allow a little more room around the camera, and their thick-walled construction should act as a better insulator against colder waters outside.

 

Another consideration is your strobe. If you use an Inon with the external TTL, it will mimic your camera's preflash and multiply it. That will cause the camera to use less strobe power.

Edited September 8, 2007 by DesertEagle

[jcclink 8]

Condensation requires water vapor & a sufficient temperature difference across the housing inner & outer surfaces. Acrylic is a much worse conductor of heat than aluminum, & is therefore more susceptible to fogging. Using an internal flash all the time greatly increases the chances of fogging because it continually adds heat inside the housing which may not be dissipated fast enough. I even had a Tetra 5050 (aluminum housing) fog a couple of times because I was taking pics too fast for the heat from the onboard strobe to dissipate. What you want is everything at the same temperature then condensation cannot occur. Keeping the system at normal ambient temperature is a big step towards minimizing the chance of condensation. This means work on your camera in the same climate as you will be using it. Or give it a sufficient time to acclimate to diving conditions. I generally stay away from AC. Working in a cool/cold room then jumping in tropical water is not good. Although AC is supposed to remove moisture from the air you never really know how efficient it is, especially in tropical areas where the units don't receive proper servicing. I'm more concerned about the AC blowing dust around when I have the housing open then maybe removing some moisture from the air. Silica gel packs definitely will help minimize condensation.

Edited September 8, 2007 by jcclink

[RogerC 4]

equilibration, temperature difference, insulation, airspace, acrylic, metal, ports, whatever....

 

fog craves not these things.

 

It's all about dew point temperature.

 

Your housing has some water vapor in it. At some temperature (the dew point temperature) that vapor will condense. The higher the humidity in your housing, the higher the temp that will happen at. Condensation will happen on any surface that drops below the dew point temp, on whatever is coldest in your system. Working in an air conditioned room means you are using air with lower moisture content. Moving a camera from cold to warm means it may get some condensation on it and carry moisture into your housing. It doesn't mean you will get fog. You only get fog when you go below dew pont temp.

 

Keep your humidity low with dessicant and it will never happen.

 

Keep your dessicant fresh and dry (get the indicator kind) and it will be reliable.

[meimei 0]

It isn't the housing, it's the camera. When you move a camera from an A/C room out into hot/humid air, condensation will occur, inside the camera. This hidden moisture will cause fogging when the camera is sealed into a housing and warmed by the internal flash. It's a good idea to keep your camera in a sealed plastic bag and let it thermally equilibrate before using it in hot/humid climates. Where there is no moisture, there can be no fogging.

 

The acrylic lens ports don't tend to fog as much as glass ports, so this is less of an issue with Ikelite housings.

 

1. Avoid hidden condensation inside the camera by using the sealed plastic bag trick, above.

2. Put a couple of desiccant packs inside the housing.

3. Seal the housing in an A/C room.

[4. A panty-liner in the bottom of the housing is cheap insurance against a minor leak!]

jlyle

 

did i read wrongly??... panty-liner?..??

[jlyle 8]

jlyle

 

did i read wrongly??... panty-liner?..??

 

Yep, panty liner. Cellulose will absorb 10cc of water per gram, that's why it's used in panty liners, disposable diapers, etc. When treated with SAP (super-absorbing polymer), it's even more effective at soaking up water.

 

Should a few drops of water get into the housing from a minor leak, the panty liner will absorb it and possibly prevent damage to your camera, lenses, or electronics.

 

Of course, if you are afraid of being teased on dive boats, you can always use a piece of a disposable diaper instead.

 

[RogerC 4]

I have started putting humidity indicators in my housings. These should warn me of even a slight leak. Fogging is one sign of a possible leak, a rise in humidity will happen before fogging.

 

These indicators show that the humidity in my housings is less than 30% when all is well, at any temp. I like that.

 

http://www.staticcontrol.com/proddetail1+1j6+11329.aspx

Edited September 19, 2007 by RogerC

[james 0]

Good thread! I need to write an article about this.

 

Roger is correct - all that matters is you understand the concept of dewpoint. In my "day job" I often consult on drying of natural gas pipelines, so I have a bit of experience here.

 

As relative humidity of air goes up the dewpoint goes up. When you seal your housing above water, you are obviously above the dewpoint as it's not raining into your housing :-)

 

When you go into cooler water w/ humid air trapped inside your housing, (say you go from 90F outside to 80F underwater) the housing starts cooling from the outside in. Pretty simple concept. Whatever cools fastest will start to condense liquid water on it when it gets to the dewpoint temperature.

 

Lexan or Acrylic are good insulators. Glass is not as good. Aluminum is not as good as any of those. So if you have an Aluminum housing the water will condense on the inside of the Al housing first - which is not a problem. If you have a plastic housing with a glass port you are in trouble, as the water will condense on the glass. If you have an acrylic housing w/ an acrylic port then it's a toss up.

 

Solutions are vapor absorbers, or to close the housing with NO or as little trapped moisture as possible inside. If you trap it with dry air inside, that dry air may have a dewpoint of 50F - so you'll never hit that unless you're in Seattle :-)

 

Cheers

James

[james 0]

OK, just for kicks I whipped out my Saturation Vapor Pressure curves :-) Yes, I'm a dork, there's no need to tell me.

 

At 30C air can hold 30 grams / meter^3 of water vapor (saturated air)

 

At 20C air can hold 17 grams / meter^3 of water vapor (saturated air)

 

So if you dive from 30C air into 20C water then 13 grams / meter^3 of water vapor will condense somewhere inside your housing. Since we typically dive in tropical spots where the air is usually saturated this is pretty scary eh?

 

Cheers

James

[jlyle 8]

One other tip: If you can't load your camera in an A/C room, you can use the air from a scuba tank to purge the housing before you close it. The compressed air in your scuba tank is supposed to be very, very dry.

[RogerC 4]

OK James, here's a puzzle for you. Let's see if you come up with the same answer Jim and I have in private and in other threads.

 

It's common to leave a housing in the sun and get fog. How can this be? the temp of the housing has gone up in the sun, not down, it should be less likely to fog.

 

Hint: it does not happen to people who use dessicant all the time.

[james 0]

Water that was inside the camera boils off then condenses inside the housing.

 

James

[bobf 0]

no facts here.....just what I've experienced.

 

5 years ago when my c 4040 Ikelite digicam housing (6140.1) developed fogging on the port, the good folks at Ikelite were surprised to hear this.......hmmmmm.............we know their integrity.......therefore it must have been a new development........a characteristic of digicams with onboard flashes?

 

what I found to be the solution for me while diving in the tropics was:

 

-storing the camera overnight in an air conditioned room

-using 3 small rechargeable dessicant packs inside the housing (larger

ones would not fit)

-one cut up panty liner in the bottom of the housing

 

the system works......

 

what I also do is place the dessicant packs away from the battery compartment of my camera (4 AA NiMH).

 

i think placement of the dessicant packs is important because i think the camera batteries may be associated with the problem of heat inside the housing. imho (not fact) the batteries may add even more heat to the housing in use than the onboard flash. placing a dessicant pack filled with trapped moisture next to the warm battery compartment might then void the benefit of that specific pack.......

 

plausible?

[LULA 0]

One other tip: If you can't load your camera in an A/C room, you can use the air from a scuba tank to purge the housing before you close it. The compressed air in your scuba tank is supposed to be very, very dry.

 

 

I recently start using that thecnique , and it works perfectly, the fogging problem stoped

[jkling17 0]

The only thing that I would add is that you turn off your camera when you are not using it. I don't have to worry about flash-generated heat as I just do natural light photography.

 

But, if I leave my camera on constantly then I'll definitely fog up after about 35-45 min. I've heard of the panty liner thing also and know of a few that swear by it.

 

Jeff

[Easydiver2 0]

My Ikelite housing for my Canon Powershot S80 does not fog up at all. I use a plastic cleaner on the inside of the lens port. The cleaner contains a defogger. The water temps are 75-82F and I prepare my camera in a cool temperature garage before I close it up and go diving.

 

On one boat dive for 57mins. 45-50ft depth I shot 159 images, note my internal flash output is set to the lowest setting just enough to trigger my external flash. If you are NOT using a ext. strobe then you may not have the option to lower the output power of the internal flash.

 

If you have to open the housing when it's hot, then try to do your work in the shade before closing up the housing.

 

Try these tips out and let us know what works or not for you. It's good to share experiences.

Charlie

[antacid 1]

I have only dived in Asia, and have not had any encounters with fogging yet. I've used the Canon A95, A620, A640, 350D in a variety of housings and have not missed a shot due to a fogged up port.

 

The water temperature ranges from 26-29 degrees celcius, and the air temp is anywhere from 28-34 degrees. The closest i've come to "blue-nuts" diving is probably in Bali which has 20 degree waters.

 

i notice that most of the newer cameras dont really have a problem with fogging, and the dessicant packs can be more trouble than its worth. i've seen a couple of housings flood because the pack was caught in the o-ring and stuff like that.

 

i usually advise DUP students not to use dessicant packs unless necessary, but leave the ultimate choice to them.

 

perhaps using the auto-power off feature on cameras will help reduce heat build-up. at the very least, turn off the LCD screen when not in use. it prolongs your battery life too. i did 15 dives on 1 set of AA batteries while in similans last year.