Camera Housing Leak Tests

Years ago, a friend of mine had a submarine housing for an expensive Swedish Hasselblad camera. I owned such a camera myself. He offered to share the housing with me if he could share my camera. I didn't think this was a good deal. In the event of a flood, the housing would survive but the camera would not.

Fast forward 20 years later. Digital photography didn't bring the financial savings we were promised. Instead of spending money on film and processing, photographers now spend their money keeping up with the latest hardware and software. This has repercussions for underwater photographers, as the latest camera needs to be fitted into the latest appropriate underwater housing, effectively doubling the cost. Often, we jump into the water with as much as $10,000 worth of gear, so a flood is disastrous. It's worse if you're a professional videographer. Modern, high-tech video cameras can cost $50,000 or more, so the financial risk of taking one underwater is very high indeed.

Gates, probably the most popular housings manufacturer for these cameras, offers a vacuum leak-test system that proves the housing is air-tight and therefore will be watertight before the assembled rig gets anywhere near water. But only one manufacturer, the Belgium-based Hugyfot, offers this facility at the moment for those using humbler stills cameras.

Instead of putting your camera in its housing and then gingerly dipping it into the freshwater rinse tank to see if you can spot bubbles escaping (with possible dire consequences if you do), simply pump the air from the housing, and watch an indicator to see if air leaks back in. In the case of Hugyfot, a built-in pressure sensor and LED warning light will tell you if it does. Air, unlike water, is kind to expensive electronics.

Install the camera in the housing, checking that all the controls are linked and functioning perfectly. Instead of neurotically checking and rechecking the main O-ring and its groove for any grit or hair that might have intruded and caused a disastrous flood, you can simply seal up the two halves of the clamshell, then check for leaks. I don't even bother to grease the main O-ring because, in use, it doesn't need to move; it is simply compressed. The air pressure inside the housing at this point is the same as that around you, and the red LEDs flash to tell you that. Two sets of LEDs will flash -- one on the camera hot-shoe near the housing's eyepiece, and one at the bottom, seen through the housing's big window.

There is an additional bulkhead connection to the housing with a cap, just like a strobe lead connection. Remove the cap and apply a vacuum pump. Hugyfot supplies an electric pump but I found that a manual Vacuvin pump, intended for removing air from half-empty wine bottles, does the job just as well. Then pump the air out of the housing. There is a valve inside the bulkhead connection that prevents air leaking back in while you do it. This takes less than a minute, and when the pressure sensor inside the housing detects a sufficient drop in pressure, the red LEDs turn to green. Replace the cap on the bulkhead connection. (I was told that if I forgot to do this, the valve inside will keep water from intruding into the housing.) Wait 20 to 30 minutes. If no air has leaked back into the housing, the LED stays winking green. It's very comforting. If it returns to red, there's a problem, and you need to start over and look for that intrusive hair or grit, but hey, at least your camera is still dry!

The little lithium battery that runs the system has stayed working for more than a week during a trip. The flashing green LEDs are not intrusive when using the camera underwater, but a quick check that it's still green just before you jump in will work wonders for your confidence, and allow you to concentrate on other things. A side effect of the vacuum test is that it pulls in all the O-rings, and seals the housing tight. It is impossible to remove the back or the lens port while the green LED is showing. When you want to do that, release the vacuum by unscrewing the bulkhead connector, and listen to the satisfying inrush of air. So much better than an inrush of water!

Evidently, there is no patent on this system, so it's surprising that other underwater housing manufacturers haven't adopted it. However, they have taken the marketing decision that "their housings don't leak." I've been using housings by nearly all of them over the last 20 years, and twice I have made a mistake in assembly and lost a camera to a flood -- you never forget such an event. I don't see these vacuum test systems as a test of the housing, but more of a test of me.

People who buy an expensive housing for their camera and want to believe they made the right decision. They tend to vigorously defend that decision. I recently had some grief on an underwater photography forum for expressing these views. I was accused of bias because some naively believed Hugyfot had supplied me with my housings at no charge. Not true. However, even if it were, I still put my own $5,000 camera inside, and I am betting that money on my decision to use that brand of housing. I would be pretty stupid to put my expensive camera into an inferior housing just because that part of the deal was free.

There is a plethora of underwater housings for cameras, and they are all good -- provided the user is good, too. You may choose to put your money on your own infallibility, but I prefer to bet that I might make a mistake at least once in my life when assembling my housing. In fact, the vacuum leak-test system has indicated to me that I've made a mistake twice since August. However, this mistake did not prove fatal, and I was able to rectify it before taking the rig anywhere near water.

Two independent manufacturers, Backscatter and Underwater Camera Stuff, now offer a similar vacuum pump facility as an after-market add-on for virtually all the underwater housings for top-end digital cameras ( www.backscatter.com ; www.uwcamerastuff.com ) At the moment, only Hugyfot offers that facility as a factory-fitted standard; its American dealer is Tackle Shack Water Sports in Florida ( www.tackleshack.com ). And though I mentioned earlier that I was surprised no one has copied the Hugyfot system, Nauticam displayed a copycat prototype at the London International Dive Show last month).

I foresee this important device becoming more popular as people wake up and smell the coffee, and more of these expensive, not-so-protected cameras become toast. Others may protest and need to be dragged kicking and screaming away from that cautious test in the freshwater rinse tank.

John Bantin, a longtime contributor to Undercurrent, is the technical editor of DIVER magazine in the United Kingdom. For 30 years, he has reviewed virtually every piece of equipment available in the U.K. and the U.S., and makes around 300 dives per year for that purpose. He is also a professional underwater photographer.