Fog on lens?
 

Today my el cheapo sony underwater housing with an HV30 in it continously fogged whenever it was exposed to cold water. Which was constantly. The air temp was 65 and the water temp was 52. I kept pulling the camera out and airing the housing but within a minute it would refog. I was whitewater kayaking and ended up killing the camera so before I kill another one I'd love it if anyone had any hints?

Some silica gel inside the housing? You're using the proper rubber seal grease before each shoot? You've carefully felt round all the seals to see if one of them has slight damage?

Tom, thanks. I haven't put silica gel on the housing seals in awhile but I'll reapply and check. But at the YMCA pool, which is alot warmer, the inside doesn't fog. Could it be the temp extremes and if so is there anyway to work around temp extremes?

No - your UWH should have come with a special tube of rubber grease that you smear all over the door seals before a dive. The silica gel packet would just sit inside the UWH and soak up the moisture in the air space.

It does sound like a temperature difference problem though. Are all the bits of kit acclimatised before they all go together?

tom.

Matt,

Be sure to put the camera in the housing in a cool, dry environment (like your room). Give the camera and housing at least one hour to acclimate to the environment in which it will be used. i.e. Don't move it from a warm car to river water.

DO NOT open the housing on the river. You are only letting the moist air into the housing which is then heated by the camera and causes condensation creating more fogging.

Tape the silica gel packet to the camera handle or inside the housing so it cannot move to help soak up moisture. Use a LIGHT coating of silicone grease to lubricate the o-rings and maintain a good seal. PVC housings are also more problematic because they do not dissipate heat as well as a metal housing.

more on housing and fog
 

I agree 100% with Rick comment.

don't turn camera on right after inserting into housing

don't put warm camera in housing or even hot battery right off charger

don't open housing unless you absolutly need to change batt or new tape

don't leave housing w camera inside in direct sunlight cover with towel anything to shade it
hits cooler water, boom fog

bag of silica helps but you need to be sure to keep it cycled, google how to heat in oven...not microwave to remove mositure between trips, keep sealed when not using, you'll find tips if you google it.

try to shut camera off rather than standby mode...heat builds inside

avoid at all costs leaving housing+camera under Air Cond, or cold car, then placing in warmer water, 1 hour to adjust, even splash some water on housing, once it feels closer to water temp, even placeing inside softside cooler filled with water is a trick often used...serves two purposed temp regulation and protection from bumps an bangs

some housing rings (Gates Housings) should never have silicone applied make sure it you do use silicone less is best

use small mag-loop to inspect your rings one bit of sand, one hair on ring

also an don't laugh, a small tampon inside housing may just save you someday it the leak is small...turning camera face lens down occasionally between clips look on housing lens on drop of water inside time to abort keep lens down if you can, it just might save the day sometime.
good shooting