Huh? I don't think any of the previous posters read the entirety of the OP's post. The OP describes lens-fogging
of his camera and wants to know what kind of anti-fog gel or spray to use to prevent it.
First of all, mask-fogging and camera lens-fogging are two completely separate animals. The causes (and cures) are very different.
With a new mask, fogging occurs due to the inside of the lens coming into contact with certain substances during the manufacturing process. Humid air inside the mask then condenses on the inside of the lens. People have various techniques to clean the inside of the lens: scrubbing with abrasive cleaner, washing with detergent, scrubbing with toothpaste, using a lighter, etc. This initial cleaning may have to be repeated on several occasions in order to be effective. After this initial cleaning, divers will use various anti-fog agents to prevent fogging during the dive: spit, baby shampoo, or proprietary goos/gels/liquids. These methods all work to a varying degree.
Lens-fogging of an UW camera has different solutions. Putting anti-fog gel on the outside of the lens port is not going to help. I really wouldn't recommend touching or treating the inside of the lens port either. If you do, you're only asking for problems. Lens-fogging on the inside of the lens port occurs due to condensation of the warm, humid air inside the case on the glass. This is caused by the temperature difference on either side of the glass (cold outside, warm inside). There are several things you can do to prevent fogging of your UW camera lens-port:
- Place one or more small pieces of desiccant (moisture muncher) somewhere inside the UW housing.
- Pre-equilibrate the air inside the UW housing to be as close as possible to the temperature of the water you'll be diving in. This can mean placing the camera housing in cool water prior to the dive. Along these same lines, don't leave your camera sitting out in the hot sun prior to your dive. Keep it covered with a towel or leave it in the shade. During the dive, I tend to turn my camera off when I'm not actively setting up or taking a shot. This can help with not heating up the air inside the camera housing and may help the batteries last longer.
- Ensure that only dry, dehumidified air is inside the camera case. The best way to do this is to load your camera inside the UW housing in an air-conditioned room prior to the start of your diving. Alternatively, some people will carefully spray some dry tank air into the UW housing before shutting the case -- don't know how effective this is, though. Minimize the times when you have to open the housing during surface intervals, since the air on a dive boat can be humid. To this end, use long-life batteries and large memory cards.
I hope that you find one or more of these techniques helpful. Good luck.
P.S.: BTW, stop spitting inside your camera housing. It's not helpful and may actually introduce
more moisture into the housing environment.
