Underwater Photography

Home : Video course : Module 2: Video Housings

There are two primary functions of a camcorder housing:

1. to keep water off your precious equipment
2. to make the camcorder inside easy to use.

With these points in mind certain industry trends have emerged with regard to how housings are sealed and operated.

When it comes to ingress of water prevention is always better than cure. Accessories such as leak detectors (electronic devices with audible and sometimes visual LED warnings that you install inside your housing) can help to give a sense of security. However, the fundamental problem is keeping water out in the first place and this is essentially a problem of design, with certain designs proven to be more inherently successful at keeping water out than others. The best designs should protect the user from his/her own mistakes - i.e. be idiot proof (because of the sad fact that user error accounts for nearly all floods).

The build quality of your housing should reflect that there is a lot at stake inside! The most sensible material to build a housing out of for use in the underwater environment is aluminium, either cast or extruded. It should be fully anodised and/or covered with acrylic enamel finish. Plastics are also used extensively in housing manufacture but are not as durable. Plastic housings also do not have the same heat sink properties as aluminium and so are more prone to misting (condensation appearing inside when taken from humid atmosphere into cold water).

Most housings are of the clamshell design, that is to say they split at some point to allow access to the inside. The two halves of a housing should open and close positively, not open accidentally, and without the need of tools. With this brief in mind manufacturers almost universally install stainless steel clasps these days rather than screws and bolts. Clasp fasteners are pre-tensioned to give the correct closing pressure and there can be no argument as to whether or not it is closed properly. It is either open, or closed - end of story! For additional idiot proofing most manufacturers employ the type of clasp with a safety interlock, which cannot be opened accidentally.

Depth rating of housings is dependent upon many variables, such as housing size and wall thickness, O-rings and structural considerations. The depth rating for housings can vary between 60M (perspex construction) and 100M (aluminium). Most housings should operate far beyond sport diving limits (to give a margin for error) which, needless to say, is also well below the depth where interesting subjects are found!

It is almost universally accepted that, in the fight against water ingress, having double O-rings on all moving parts that go through the housing is a good idea. Let's face it, one of the basic principles of diving is that you always have a backup and double O-rings on all control lever shafts give added security and longer periods between maintenance. You can't see them but it's nice to know they are there!

The hidden O-rings around control shafts can suffer abrasion, which will challenge their integrity, if you allow salt crystals to form by drying out. It is vital that you maintain your equipment by regular and prolonged (all night) freshwater soaking (not a rinse under a tap) after each diving day - and do not let it dry out after the dive before you get it to freshwater. More about maintenance later...