Fogged Housing and Camera:
While diving in Indonesia’s Lembeh Strait this past September my Olympus Tough TG-056 housing fogged up, making it impossible to take photos. The air and ocean water temperature were both 27 to 28 °C, with high air humidity.
To prevent further fogging, I tried the following without much success: drying the inside of the housing with a towel, washing it with mild soap and water, and drying it with compressed air.
Then a kind lady diver gave me some packs of desiccant. After I had dried the inside of the housing with compressed air, I put a desiccant pack between the bottom of the camera and the housing, with no more fogging for the remaining two weeks of diving.
While this was happening, and to make my life more interesting, the inside of my Tough TG-4 camera’s front lens also fogged, maybe because when I removed the battery to charge it, I left the battery/SD compartment door open.
As a remedy, I put a pack of desiccant inside the battery compartment; then I put the TG-4 camera and three desiccant packs inside a dSLR housing and pumped a vacuum with its vacuum leak detector. I left the camera in the evacuated dSLR housing overnight, the fogging disappeared and has not recurred.
Suggestions: To prevent fogging of the camera lens, keep the battery door closed, and use a USB cable to connect the camera to a computer to download the photos and charge the battery. The battery can also be charged with the USB cable and the USB electric charger.
Before closing the housing, dry its inside with a towel, and with compressed air blow out any moisture trapped in small spaces, such as behind the push button assembly. Then promptly insert the camera and desiccant, and close the housing.
Or, close the housing with the camera inside, and place it in a refrigerator for 10-15 minutes to cool - the housing needs to be closed so that moisture from the refrigerator does not condense in it. If the housing fogs, open and gently dry its inside and the camera with a towel and/or compressed air.
Put a desiccant pack in the space between the camera’s bottom and housing, and close the housing. If no pack is available, with a nozzle blow compressed air into the almost closed housing to replace all the wet air and immediately lock the housing (this has previously been suggested in these pages).
It is a good idea to have several new desiccant packs; used packs can be regenerated by brief heating in a microwave oven.
All the above is rather obvious, but at the time I searched the web for a solution to fogging and did not find one, and as I had not before used a desiccant pack I did not consider it until the kind lady diver gave me one - I hope my story is useful.
p.s. The topic of “Housing Fog” was started here in 2007 with comments through 2009; I am resurrecting it 8 years later.
It is amazing how many creative approaches and solutions underwater photographers come up with to combat fogging.