| Unfortunatly auto white balance will not compare to manual white balence.The former works on the basis the camera "sees" some white in the intended shot and then sets all the other colours off from the white.Underwater there will be no "pure white" as the blue or green tint of the water will fool the camera into setting it's colours off that,with the resulting effect of colour misrepresentation.
Manual white balance requires you to take a pure white referance with you and each time you take a shot you would point the camera at the referance and "tell it" to set it's colour balance off it,rather than the sourrounding water.Note colour balance is both specific to and remarkably varient at quite small changes in depth.
Sony video cams judge their white balance through the lens so you need an external white referance and the case must allow you access to the manual white balance button(s).
Some high end Panasonic cams have a seperate dedicated white balance sensor and the trick then is to place a piece of pure white card INSIDE the case infront of the sensor.You can then run the cam on automatic white balance as long as you switch off/on each time you move up/down more than 4mtrs.The internal card gives the cam a constant pure white referance which it uses each time it is switched on.
The trouble with filters is the reduction in light coupled to no effect beyond say 15mtrs (and thats just when you need every bit of natural light going).  |