Lesson 7 The Underwater Photo Course
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Care and feeding

Whatever your camera, it is basically some fine engineering, optics and electronics which cost you a lot of money, and its only protection against flooding with sea-water is a few pennies worth of thin rubber O-rings. It makes eminent sense therefore to lavish as much care and attention on these little rings as is humanly possible.

O-rings seal by loosely filling a groove when assembled, and when one side is subjected to pressure, the O-ring progressively deforms to completely fill the groove space, forming a most effective air or water-tight seal. As the raw material of the O-ring offers some frictional resistance against this deformation, an essential part of the mechanism is a very fine lubrication layer on the O-ring permitting it to slide into its final resting place as the pressure increases.

An O-ring seal is so effective that it can withstand pressures of 300 bar and more, and is routinely used to make high pressure seals in diving equipment, yet the design of the seal is also often important, and a seal designed to resist pressure from one specific direction may be easily dislodged if pressure is applied from the other side.

Do bear in mind that it is this pressure that makes and keeps the seal intact, and for that reason your camera is at its most vulnerable when it is in the water, and the pressure difference is very low, such as at the surface. Jumping in the water with your camera is, to my mind, a form of Russian roulette - you'll get away with it a few times, and then find your camera full of water. For the same reason, many floods have occurred in the rinsing bucket after the dive by some over-enthusiastic dunking in and out.

However an O-ring is only so deformable, and relies on smoothly engineered surfaces to slide upon and to seal against. Inevitably, damage to those surfaces, such as scratches, or contaminants, such as dried salt crystals, sand, or hairs are beyond the O-ring's capacity to deform around, and a weak spot, or even an incomplete seal may result. This is what leaks are made of, and little leaks will, in time, become major floods.

Some O-rings in a camera or strobe assembly are termed 'user-serviceable' meaning that you should remove and clean them every time they are disturbed. Examples are doors, battery compartments, and strobe connections. Others are classed as 'non-user serviceable' and can only be maintained by qualified service personnel. These tend to be through-casing control shafts such as aperture and focus adjustments, or the host of other adjustment features found on camera housings.

Care and maintenance is about keeping your equipment in top condition, keeping even stray water droplets out of sensitive equipment, and keeping O-ring seals secure. Remember that sun, salt, dirt, and careless handling are all eagerly waiting to ruin your fun.

Do's

Pre-dive

Post-dive

General

Don'ts

Be careful

Some sources recommend the use of materials such as WD40, and Silicone Fluid to lubricate and waterproof moving parts, including shafts with O-rings. Others warn about the dire consequences of their use on certain parts of your equipment. If you must use these chemicals, and there is a place for them, never spray them onto your equipment. Instead, spray the end of a cotton bud, and apply the lubricant with that. Similarly on the subject of spraying, be careful of 'air cans' that contain liquid contents, and keep them upright when using them on your equipment to avoid liquid sprays in the wrong places.

Threads

In many cases, O-rings are used to seal compartments with threaded covers, such as the Nikonos V battery compartment, and especially strobe lead connections. You will be very conscientious about cleaning these O-rings, but may well ignore the threads just next to them which have been immersed in salt water, but which are unlikely to have been properly soaked through in fresh water.

Take the time to carefully clean these threads, both connector and camera, every time you clean the O-ring, and get all the salt water out of the connection, before greasing lightly with silicone grease. Often the threads of the connector and the threads on the camera are made of different metals, and this will cause electrolytic corrosion, so keeping them clean and well greased will help prevent corrosion, which if bad, can lock the two together so severely that you may not be able to get them apart without damage.

You will find other threads, especially on your strobe arm, so be sure to treat these with equal respect, and clean and grease them regularly.

Floods

Someone once parodied John Wesley by saying "An ounce of prevention is worth a pound of cure". This may be very true, but in our case it is likely to amount several hundreds or even thousands of pounds worth of cure, and an unhappy insurance company.

The bottom line is - "If the camera floods - it's your fault". There are no excuses, and no-one else to blame. You probably:

Whichever one it is, you may or may not get sympathy from your buddies, but it will have ruined your day. Don't let it happen to you!

The corollary is - "Never touch anybody else's camera". If you are forced to use somebody else's camera, have them assemble and test it, and give it to you in the water. That way, if anything does wrong, it's their fault and not yours!.

In real life however, floods happen. In my short time photographing, I have already had three strobe connector floods, and have irreparably flooded a Nikon F90 and 60mm lens. It hurts. Don't let it happen to you.

Even if you do get a leak, by being careful, you can keep the damage minimal rather than letting it develop into a disaster. Two hints are

When the unthinkable happens

If the unthinkable happens, (it needn't be "when" if you're careful), and your camera does flood seriously, first aid includes

I actually had an opportunity to put this advice into practice in August 1997. We were on a week's liveaboard, and one of the other guests managed to flood a Nikonos III and a U/W Nikkor 15mm lens. He was understandably depressed and quite resigned to the fact that his week's photography was at an end. I usually carry a set of jewellers screwdrivers with me, and on this occassion, as it was a manual camera, we stripped them both down, dried them thoroughly, and re-assembled them. He was back diving with it within 6 hours.

Realistically, most of this isn't really going to help if your camera has any degree of sophisticated electronics in it. Modern cameras (since Nikonos III) are largely unrepairable if flooded, and the standard service treatment for a flooded Nikonos V body is a complete new inner body mechanism at a cost of about two thirds of a new camera.

Flushing with water may help to reduce the salt content in the camera, but is unlikely to remove it completely, as capillary action will help the salt water seep into places you'll never remove it from, and where electrolytic reactions will start eating your camera away from the inside. Even if you are in a "Technical" environment, where you can flush with plenty of de-ionised water, freeze-dry it, and pack it away in a pressurised container full of inert gas, it probably won't help you. Much of the damage is done in the first few minutes, and it will invariably end in tears.

Not all floods occur through the main O-ring, and flooded flash connectors are especially entertaining, as they apparently will permit water to run up wires and through bulkheads, flooding in addition to the cable, probably both the camera and strobe. Flooding of the lens O-ring on the Nikonos V will frequently flood both the camera and the lens.

Careful and thorough maintenance is the key to avoiding floods, and careful and observant descents is the key to preventing them from becoming complete disasters.

Subal housing maintenance

Preparation

The main O-ring is a gasket rather than a piston seal so leaks will usually occur through this O-ring, and it must be carefully prepared before each dive.

Loading and unloading

After the dive, don't let housing dry in the sun, keep it off the deck don't point it into the sun (this can damage or destroy the shutter curtains) rinse well after every dive, but be careful not to cause a flood in the rinse bin by mishandling, or by piling cameras on top of one another.

Maintenance

Don't attempt to maintain internal O-rings as they need special tools to safely remove, and are hard to put back. They can however clog with sand and mud, so operating all control levers when rinsing is very important, as is a regular service.

Scratches on dome or flat ports can be avoided by careful handling, and the use of protective port covers when not underwater. However, if they do occur, then external scratches are not so important as they will be filled up with water on a dive and not noticeable. Internal scratches are another matter, and will adversely affect your image quality. These may need polishing out, or can on occasions be masked out by filling them with black paint. In either case, seek professional advice before doing anything.

Essential tools and spares

A toolkit for photographers might contain:

You may choose to add to this list, particularly if you are going on a long or important trip. If you feel that you would be able to change it under 'field conditions', then bring along a spare strobe lead, and if your trip is particularly important, bring a spare camera and strobe.

General preparation and maintenance

Keep your housing clean and free from grease and dirt. Wash it regularly with a very dilute solution of mild detergent using a small sponge or cloth to clean any oil or grease from the external and mating surfaces.

Clean lenses with specialist lens cleaning fluids and tissues. There are new quick-drying polymer films which can clean lenses exceptionally well, so use these occasionally, but be careful to follow the instructions for use, and keep the fluid away from the lens mountings.

Never use any abrasives, even mild ones such as toothpaste, and certainly never use any sort of chemical solvent, even alcohol, unless it is a part of an approved lens cleaning fluid. Sea and Sea advocate the addition of a cup of white vinegar to a sink of water when rinsing their equipment, and this is therefore OK for their camera gear.

Storage

Inevitably, however keen an underwater photographer you are, there will be long periods of time when your equipment will not receive any use. To keep it in top condition, you must store it correctly.

Of greatest importance is making sure everything is properly dry before storage, I'm sure that you have seen diving masks with fungal growths around the edges of the glass - so don't let your camera equipment get in that condition.

In general:

One last point involves protective cases. Many underwater photographers use rigid sealed cases, such as those marketed by Pelican and Underwater Kinetics. These contain pluck-foam to provide a firm fitting for your equipment.

If, like me, you sometimes need to put your equipment away in the case every day on vacation, there is no doubt that by the end of the week, the foam has absorbed quite a bit of salt water, however careful you were. Salt itself is hygroscopic, that is, it will attract water out of the atmosphere. This being the case, the foam will never truly dry out if there is salt left in it. It is well worthwhile, once you get home from your vacation, to remove all the foam and wash it thoroughly in fresh water, squeeze as much water out of it as you can, and hang it up to thoroughly dry. I allow at least a week, and it can frequently take as long as that before the foam feels dry to the touch when squeezed.

Wash out, and dry the inside of the case, and remove and service the O-ring (why should this one be left out?) before putting the foam and your equipment back in. In this way you can be sure that your equipment is in the cleanest, driest condition before leaving it for months at a time.


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This page was last updated on 11 August 1998
Please address any comments to Mark Mumford