Colour filters? Green/blue

[e14724]

Ive got green and blue water filters for my video camera. Looking at previous videos of capernwray (where im doing a bit of practicing until the weather sorts itself out!), the water can appear green and blue. What filter would you recommend?

What would happen if I used both?

FYI i cant alter the WB whilst under....

My previous test i used the blue, as i had a problem with the green, it may have to be try it and see.....


Cheers

[Okeanos]

You should use the green. Colour filters are only a stop-gap and will give different results at different depths in different conditions. Custom white balance is the only way to go unless you are using lighting of some sort. The blue may be better in the very shallow water. Past 15m neither is gonna help much anyway.

Don't bother trying both, you'll be cutting out too much light.

[e14724]

I will try the green filter next time out and see how it compares. Ive also got some lights on order from the states, not the best available but sufficient for what i will be wanting to achieve. £200 including postage 2X50 watt Xenophot halogen on 12" arms with 45 min burn time. They seem ok, and im not in a position to spend anymore... fingers crossed

I have been leaving the camera on auto white balance, this is different from full auto mode, will this have a similar effect as doing a white balance check before each shot?

Sorry about sounding too dense

[reef hook]

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).

[e14724]

Ive just had alook at my panasonic camera and it does have a white balance sensor. So, if i place a small white card in front of it inside the housing, before each shot a quick on-off will balance the colour for me. Does this eliminate the need for filters as the camera now "knows" true white and can adjust for the colours it is seeing?
Sorry for sounding dense, im still very new to all this....

[e14724]

Ive manged to rig up my housing to allow me to alter the WB, ive sacrificed one of the other controls. Wow what a difference, i put a colour filter on and then altered the WB, the result was as if it had no filter on!

Thanks for the tips