Tuesday, January 30, 2007
Trade Tricks: Underwater Digital For Travelers
Create amazing images beneath the water’s surface with your digital camera
Many housings are designed for specific camera models. Available either through the camera manufacturer or a third party, housings provide a rugged casing with a depth rating of as much as 40 meters (about 120 feet). They also feature full access to major camera controls. Housings such as the Olympus PT-020, which accommodates the Camedia C-5060, and the Canon WP-DC300, for the Canon PowerShot S50, are built to withstand the increased water pressure as you swim deeper.
Such housings incorporate an O-ring gasket that provides secure closure and prevents water from entering the compartment. Before taking a camera into the water, properly lubricate the O-ring with compatible O-ring grease. Check that there's no debris in the O-ring's channel and that the O-ring is clean and flexible.
Before entering the water, submerge the housing into a pail of water to ensure water tightness-without the camera. If there are no signs of leakage (bubbles rising to the surface), insert the camera and close it securely.
After diving in salt water, submerse the housing in fresh water for 10 minutes. After gently rinsing it, dry the housing completely and remove the camera.
The Ewa-Marine housings offer an alternative to the camera-specific housing. They're made of double-laminated PVC sheet and include a lens port, made of flat optical glass, and a large clear window for the camera's LCD. With numerous designs for a variety of cameras, the flexible housings often are rated to a depth of 10 meters (about 30 feet).
Getting The Best Picture
Almost immediately after passing through the surface, red light is absorbed by water, resulting in a bluish tint to images (when the camera's white balance is set for daylight). To compensate for this effect, set the white balance to the Cloudy setting to warm up the scene, or you can set a custom white balance on a blue card to compensate.
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