Underwater photo : avoid fog

[john_ackbahr]

Hello!

I'm going to dive in Thailand during the Easter holiday, and my

previous photographic experiences while diving were a bit frustrating

: after ca 20 minutes, I use to have fog on the internal side of the

glass of the underwater box, so that photos were impossible. I want to

avoid this.

I heard about Silica Gel bags, and I think this would be the best

solution. But I also read about a liquid stuff that would avoid fog

when you put it on the glass. Does anyone know about it?

Thank you very much!

[vandit]

That liquid stuff is defogging solution, or baby shampoo - however, I would hesitate to put it on something that is in the optical path. Use a couple of silica gel packs - they work better.

 

Vandit

[jeff_phillips4]

What you really want to do is avoid getting moisture of any kind inside the waterproof case. Moisture leads to fogging. This can happen if your case or camera come from an air-conditioned area and then go directly outside (condensation) or, if you have water that got into the case by splashing or some other method. Make sure you thoroughly dry your case before you place the camera inside and then seal it - but do this outside the air-conditioned area (if there is one) of the boat. You can use a silica gel packet inside the case, but anti-fog solution will kill your clarity and make your pictures useless. I've never put anything into the case and only experienced fog when I go into a colder-water area when the atmosphere is hot on the surface or when I didn't seal the case properly (which can be dangerous, as you can imagine).

 

DO NOT USE THE LIQUID! How's that for emphasis?

[vandit]

If you are in Thailand, getting moisture in the case may be hard to avoid. I know someone who flushes his housing out with air from a scuba cylinder - dunno if that hasa big impact of no.

 

Incidentally, other than temperature changes, the heat from the internal flash of the camera can also cause condensation on the inside.

 

Vandit

[liquidlifephotography]

Hey there John,

What type of camera are you using?, through experience i have found that certain cameras are a lot more prone to this problem than others, for some reason especially canon p&s with housings....as mentioned best thing is to avoid any moisture in the first place, so prepare you camera in an air conditioned room in advanced, keep it cool when not diving, (in the shade in, a bucket of water{saltwater will be fine, but use fresh for final rinsing}), and try the gel bags.

If you can also avoid using the internal flash this will help loads in preventing the camera heating up, carry a underwater torch with you to light your subjects.

Best of luck,

Barb.

[frank uhlig]

If the water in front of the window is cooler than the air/camera inside the underwater case , you will get condensation if there is enough moisture to condense.

 

So: start out with a cool camera, do not heat the inside of the case too much with the energy of flashes and make sure the air inside the case is dry.

 

These are rather stringent and counterproductive requirements. So selica gel, bone dry to start with seems to be a must.

 

When done put the selica in the microwave/toaster oven/sun/... to dry completely for better absorbtion of moisture.

[mete_uz1]

The only time I had a similar experience was diving in a high-altitude lake partially covered with ice. The problem was frigid waters and high summer humidity in the air. The simplest trick I found was to put the housing in the water some time before the dive but let the dome port stick out so that condensation formed outside the optical path. Once you have removed much of the moisture from the air inside the housing you are safe to submerge the dome port as well. I think I needed about half an hour for a plastic housing. Aluminum should be faster.

[clauder]

the 'flush the casing with air from a scuba tank' is a good one...

 

SCUBA tank air is extremely dry (it must be, to avoid corrosion, and more importantly, avoid freezing of the regulator when diving in cold water)...

 

even if it is not really possible to get all of the ambient air out, it still should reduce the moisture inside the case a lot (almost close the housing, and blow in the ait through the remaining slit, that should make it a whole lot better)