Oly 4040, Oly pt-010 awful fogging, need housing suggestions

I had a 3040 and had no fogging problems with the same Oly PT-010 housing. The 4040 fogs after a lot photos are taken on a dive, even in warm 83 degree water. I will be doing more cold water diving as well as the warm diving.

I tried defog liquid and silica packs. The defoghelped a bit, but the housing eventually fogged on nearly every dive. I tried setting it up inside an air conditioned room, but it fogged immediately after taken outside and then took time to clear so not much better.

Does anyone have any new ideas (I reviewed forum history) or housing suggestions? I havea feeling it is a combination of a small housing (little air space), and a camera that gets HOT, even with the flash on the lowest setting to trigger external strobes.

I've never had a problem when I used the PT-010. I've alway put in 3 small silica pack.

If you set up your camera inside an air conditioned room. Close the housing before leaving the room. I don't see how the inside can fog if you do that. Fogging on the outside does not matter.

I think you're right that the difference between the 3040 and the 4040 is the amount of heat created. If anything you should be setting up in a warm environment, not a cold one.

When you use the silica pack, put it in a while before you dive. These things take time to absorb water so I suggest you give it time to produce super-dry air inside the housing. That always worked for my 4040.

Also, make sure you're using a fresh silica pack. If it has been exposed to outside air for a while, it's worthless until it's been "recharged".

It is unusual to have major fogging in the PT-10 housing. It is larger by volume than most of the 'plastic' housings. In areas of high humidity you do need to, when ever possible, seal the housing in an aircon room. This will reduce the moisture content of the air inside the housing and therefore reduce the possibility of condensation forming. When you take the housing from a cold aircon room outside it will fog up but this is usually on the outside only and clears when you hit the water. The temperature inside your housing is always going to be hotter than the outside sea temperature, the secret is to reduce the moisture content of the air inside the housing. I have not had to use silica packs nor anti fog solutions in the PT-10 housing with an C2040.

Dumb question, but are your silica packs good? you keep them in a bag or something, and they're blue, not pink, if they are the kind that change color, right?

Cold room is preferred. Cold air holds less moisture than warm air, and air conditioners draw out even more moisture.

Set up your camera as soon as possible, let the silica do its job. If you can let the silica work for an hour or so, there's no way you should get fog if the silica is working at all.

Excessive fogging is usually caused by a leak regardless of housing material or manufacturer. The leak can be imperceptible, but it is allowing the moisture that allows fogging. Aluminum housings are susceptible to seepage through the aluminum. Plastic housings don't have this possibility unless they crack, but any "O" ring seal can gradually pass a slight amount of water.