Survival of the fittest - weatherproof, splashproof, waterproof

We think nothing of driving in torrential rain – why should taking pictures be different? 

If you think keeping water out of a camera is tough then just consider how effective simple door overlaps and rubber strips are on vehicles. Some people bullishly dismiss rugged cameras, confidently proclaiming that a little rain never hurts and that they never worry about it. There's some truth in this - fresh water is quite benign stuff, and light rain droplets don't force their way in on their own. On top of that good cameras aren't made just for good people, they have to work across the world, suffer accidents, and survive spills. Humid latitudes, photographer's perspiration and air conditioning add extra stress to the designers' lot – and that's before we consider the sea – the deep, wet, corrosive sea...

So is your camera 'proofed' against everything or anything? Even if it should be, do you trust it enough to actually test the manufacturer's claims?

No entry?

It helps to start by understanding what it takes to keep water (and other unwanted stuff) out of a camera, and why perfectly sealing it isn't as easy or entirely beneficial as you might think.

An umbrella will keep you dry, it simply stops rain falling on you. Similarly, most cameras can cope with a few light drops of rain. Think about it, it doesn't take much to ensure that small quantities of unpressurised moisture won't fall inside - as simple as including gutters around apertures and avoiding open holes in the top. Upper controls and fittings simply need to overlap any openings through the casing. Card and battery doors just need to overlap and gaps should be small and tight - surface tension just won't let water fall through a hairline crack. 

Professional DSLRs such as Nikon's D3X come with weather-sealing around their major control and access points (marked here in yellow) but interchangeable lens systems are difficult to totally waterproof.

Stopping rain is only the start of the story. Humidity can also be a problem. I takes pretty serious sealing to stop gas, and as a result, airborne humidity is constantly passing in and out of most cameras. It isn't impossible to hermetically seal camera bodies, but it isn't necessarily practical. The volume of cameras can change quite dramatically as their lenses (either built-in or bolted on) are zoomed in and out.

So normal cameras have to cope with everyday environmental stress without being airtight. If you're the kind of person who goes in when the rain starts to get heavy you may be the best friend your camera has.

Rating

There are some standard ways to rate environmental protection. The most widely used and understood is the IP (Ingress Protection) rating system - a numbered scale which details protection against solids, liquids and impacts. I won't quote it verbatim but there's a good summary here. http://en.wikipedia.org/wiki/IP_Code The first digit indicates the protection against solids, the second liquids. The top rating IP68, for example, is dust tight and proof against immersion, a garden power outlet for example might be rated to IP56.

The IP scale coincides somewhat with the American NEMA ratings – although they're not exactly the same - and the Japanese JIS ratings correspond to the second digit of the IP system. The table below shows the IP ratings of the cameras we tested in our recent 'Compact Waterproof' Camera Group Test.

 Camera Rating
Sony TX10 IP58
Panasonic DMC-TS3 IP68
Fujifilm XP30 IP68
Pentax WG-1 GPS IP68
Olympus Tough TG-810 IPX8
Ricoh PX IP68

The IP rating system maybe a little technical but it is definitive, unlike the completely misleading depth ratings on watches which flatter only to deceive. Given how comparatively simple it is to make a waterproof watch I'm at a loss to know why else they make such a meal of it...

Wither without weatherproofing?

Of course cameras which don't claim any degree of resistance still shouldn't keel over at the first spot of rain, but their vulnerability is an unknown quantity. Sensible design lets you use them under normal conditions, but what counts as 'normal' is impossible to establish.

If your camera has no specific weatherproofing specification, you have to decide what your own threshold for risk is. Mine increases as the end of a holiday approaches and depends how many cameras I'm carrying. I'd suggest that anything more than light rain should normally be the trigger to cover your equipment up.

Humidity is harder to recognise and deal with, people assume hot air is dry - it isn't. They think cold air is wet - it isn't. Air can hold more water as it gets hotter. Managing the transition from hot/wet to cold/dry air is key. Condensation on the exterior of your camera isn't a big deal, but condensation inside most definitely is. It's best to bag the camera as you move between environments and allow the camera time to warm up, inside the bag. If you need to dry electronics, air conditioning is your friend, because the same air that dries your sinuses will draw moisture out of the tightest cases (as will immersion in dry rice).

Weather window

A lot of cameras out there do include some degree of weatherproofing in their specification, but definitions vary from brand to brand. It is very important to read the documentation that came with your camera (or the specifications, if you're at the purchase research stage) to establish exactly what might be meant by 'waterproof' or even the more vague 'rugged'. 

I think the definition that Olympus offers is a good one; 'weatherproof', meaning protected against water splashed from any direction. That tells you what you can expect, - proofing against moving droplets or falling water but not immersion. Olympus proudly declares that its entry-level Tough-series compact cameras are protected to the IEC standard 529 IPX4 – which if you look up the code does indeed indicate protection against splashes, but the leading 'X' means it isn't tested against solids (such as dust or sand)

Performing seals

Weather sealing is simpler for some camera types than others. Flat, folded optic cameras have a head start since they don't need an external moving lens mechanism. They can be  sealed behind a flat pane - air exchange isn't a problem as the case doesn't change in size. As soon as something external has to move you need 'real' seals. These seals have to be in contact with both surfaces, preventing ingress and wiping away any standing water without interfering with handling. Almost all lenses have some dust sealing but velvet pile doesn't stop water - it soaks it up and spreads it out! Concentric lens seals have to be impermeable and hard wearing - a diver knows to maintain his seals but John Q public is rarely aware of his responsibilities.

O-ring seals on the USB/power compartment of a compact-camera... ...and on a waterproof housing.

These seals are always living on borrowed time, they work while they are clean and tight but use will wear them and they will eventually fail. You can help them by clearing water, dust, debris and unidentifiable crud yourself. Surface seals rely on their softness to conform to mating surfaces.

Splash dance

After weatherproofing the next marketing leap is typically 'Splash proof'. This suggests increased resistance to water, but actually, this loose definition is also covered by the IPX4 'weatherproof' rating. So in fact, the degree of proofing on a camera marked as 'splashproof' is not necessarily and more - or better - than a cheaper, 'weatherproof' model. 

There's another subtle wrinkle here as cameras with interchangeable lenses appear to struggle to conform to formal ratings because changing lenses voids any protection. If you attach a non-weathersealed lens to a weathersealed DSLR for example, and the lens gets wet, water can easily enter the supposedly protected camera, via the lens. 

The upshot is that as far as I am aware, there is no formal rating for any of the big, professional D/SLRs that you might expect to be most upfront about their limits – or lack of them.

Anecdotally, the Pentax K-series vie with Olympus' flagship models as the most resilient. If you've ever been to a trade show where these models are demonstrated, reps for both companies never flinch from dousing them. However, neither pins their flag to an official IP rating.

The big boys are much more coy about their gear although the likes of the Canon EOS 1-D Mark IV/1-Ds Mark III and Nikon D3S/X are workhorses designed to serve in all weathers. Utimately, flagship bodies really should (and do) shrug off downpours but their protection is undermined if you don't look after seals or invest in similarly-sealed lenses.

Beyond wet - waterproof

DSLRs aren't waterproof. They cannot be immersed - at least not for any length of time. A DSLR might survive brief immersion in fresh water if fished out immediately (and thoroughly dried out) but protection against immersion isn't a design feature (and of course, there's no guarantee). The toughest cameras you can buy aren't DSLRs, but compacts. 

There's a breed of waterproof compacts which can laugh in the face of puddles, and even rivers and oceans. If you've browsed the IP rating system you'll have noticed that it stops at immersion beyond 1m (3.25 feet). Immersion moves the goalposts; water surrounds every weakness and as you go deeper it presses in with increasing pressure. One of physics' most beautiful coincidences is that for every 10m (33ft) of depth another atmosphere (1 bar or 14.7psi) of pressure is added to the army of molecules trying to enter your electronic toys. Cameras that are specced to breach the surface of of the sea don't just need seals to direct water away, theirs must resist pressure, as must their controls.

As you'd expect this level of protection is a step up, - four steps up in fact. These models are protected to the IEC standard 529 IPX8, which means that they are rated to survive immersion. All the cameras in our recent 'Compact Waterproof' Camera Group Test come with this rating.

The Pentax WG-1 GPS and Panasonic DMC-TS3 both come with an IP68 rating which does certify them against immersion in water.

Some of the waterproof cameras on the market ask you to limit how long you submerge, but most are truly aquatic. The difference between the seals to achieve ratings of 3, 6 or 10m is minor and, I think, mostly down to market differentiation. In fact after abusing a few of these models quite extensively I know that there's a lot of safety margin, and there needs to be as the instructions on maintaining seals are usually minimal. I've taken new cameras to double their depth ratings without any harm but I'm not sure how long you should expect that level of protection. That margin allows the advertised rating to be viable for a reasonable time. Ratings count for something fresh out of the box but once used they are on borrowed time - extended with care, but reduced by abuse.

Now we've walked through water resistance I think you'll understand how critical every little bit of rubbery gap filling is. I've seen dumb divers swab down the seals on their equipment with fluffy towels and crud covered fingers but to work well seals need to be in complete contact. Hair, grit, dust and salt crystals are all lining up to lift seals and let the neighbourhood in. A quick wipe with a clean finger is often the best solution.

Beyond waterproof - Dive housings

For divers even 'waterproof' isn't enough. Normal recreational divers need protection from water pressures up to 4 atmospheres (about 60psi). The Holy Grail of a waterproof deep sea camera has been abandoned since the famous Nikon Nikonos. The continual churn of digital photography provides much less incentive to invest in the development of compromise cameras when there's a vast choice on land. Today's divers shoot with conventional cameras, but preserve them inside special waterproof housings. 

Dedicated underwater housings, such as this model from Ikelite for the Nikon D7000 can withstand much higher water pressures than even the toughest 'rugged' compact camera

Any seal or o-ring needs to be inspected and cleaned if necessary. There's a dive culture of obsessive cleaning which can be just as dangerous as lack of maintenance - a working seal in good condition doesn't need attention! The danger is that any disturbance will introduce new material. I've been away for 4 weeks and never removed the main seals, just cleaned their exposed surface. These seals are also greased, another point of zealous ritual! The grease is lubricant to allow the seals to move into place so very little is required. People tend to slap it on so liberally that it actually collects debris. This is not a good idea. The last wrinkle divers have to look out for is that the right grease is used... soft coloured silicone seals are not compatible with regular silicone grease and should only be treated with the type of goo that comes with the housing.

Salt of the earth

One good very reason for having a water-resistant camera is that you can wash other nasties off it. Oddly after using a camera quite hard a cold-blooded wash down might seem callous, but if you work near the sea, amongst dust, or take a careless latte over the camera in a Starbucks, being able to hose your baby down is a boon. Seawater is evil stuff, corrosive, abrasive and capable of lifting seals. You do not want to leave it to do its work, freshwater can be your friend!

Pros can laugh off a lot of problems; they change gear often but while they work it hard they also know how to care for it and will miss some of the long term effects. Those tend to bite careful amateurs who hold onto prized gear for longer.

The Bottom Line

There's plenty of talk; words like durable, robust and tough don't mean much on their own. Only if they are backed up by ratings and reassurance can you really expect any real protection. Companies which document the resilience of their products are generally more sympathetic to claims if damage does occur.

It's very confusing, and all the more so as it's the users who really get to test this stuff. Obviously there's a certain amount of reticence to test the limits amongst people with less money than sense and simple lore tells you that pride comes before a fall. The camera that's never taken to sea will never be filled with saltwater when a seal fails. Some of us have to work close to the limits; we need to take pictures at sea, in rain and snow or even underwater and many of us will have suffered casualties.

All the care you can muster will just delay the moment when something will go wrong... but don't dwell on it, use your toys as they were intended – get insurance if you are losing sleep!

Reference
IEC Standard publication 529


Rob started SCUBA diving around the birth of practical digital photography with some of the earliest housed compacts. Now he specialises in Great Britain's marine wildlife and helps runs the Marine Conservation Society's Seasearch project in the East coast. He has a technology background, used to working on a range of weird and wonderful things - pictures and video from racing yachts, video analysis and even digital cinema systems. His pictures appear in press and print, are used by wildlife conservation bodies and government agencies and there are even finger puppets based on his favourite seaslug! Visit his website for more.