underwater Photo Course :: (2) Equipment Guide :: Underwater Camera Housings :: Digital Underwater Cameras :: Design
Camera Housing Design
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U/W Photo Course
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Most housings are of the clam-shell design, that is to say they split longitudinally
down the middle 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 steelAn alloy of Iron Chromium Manganese Silicon and Carbon (May also contain Nickel and Molybdenum). A4 stainless (AKA type 316) is completely resistant to seawater corrosion and is the preferred grade for marine applications.
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, a housing 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.
Compactness is a major factor in choice of housing for the travelling photographer. The
larger a housing is, the heavier it must be in order to remain neutrally buoyant in the
water. Bulky units not only take up more space, but also contribute to excess baggage
charges and aching arms! The trend now is to build a housing for a specific camera. It can
then be constructed to 'fit like a glove' and allow you to operate 90% of the
cameras' controls.
Camera manufacturers are now producing their own underwater housings and it is tempting to think that you can purchase
one and start diving. You still need a strobe and therein lies a minefield of compatibility issues. It is best to develop a
relationship with a specialist supplier, who can give you the right advice. More often than not, a third party housing manufacturer is the best solution for your camera because it will provide the best system components.
Depth RatingThe depth you can take underwater photo equipment to before it floods!
Most aluminum 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! The depth rating of a housingA casing or box with waterproof seals designed to contain a camera or other equipment in such a way that it can be used underwater. is dependent upon many variables, such as
housing size and wall thickness, O-rings, and other structural considerations. The depth
rating for housings can vary between 30'/10M and 300'/100M.
Typically, perspex housings have a lower depth rating than aluminum.
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