I never suggested strobe light was infinite. And I never suggested that filters have no value (I use them in my day to day topside shooting). What I am suggesting is that they have limited value in general shooting underwater.
I have tried various filters underwater - in almost all cases I hated the effect as the images became very unnatural looking. But if you have some ideas on particular filters that may work well underwater, let me know - I am always willing to try something for a dive or two to see if it does something worthwhile.
Your milage may vary. I know mine does.
M
What you said was that times where strobe light would not be "sufficient" were "inconsequential". In other words, strobes will always be powerful enough. That is what you said. You also said "... but I (personally) can't see a reason to use one ...". You position is clear and I did not misrepresent it.
Let's face it, Paul. You're predjudiced against filters like 99% of the uw still photographers out there. If the pros don't use them they can't be worthwhile. All the technique there will ever be has already been developed. It's interesting that you broadly dismiss filters as "unnatural looking" yet you shoot through the worst possible filter there is, the water itself, on every single shot. Just what is "natural looking"? Turn your strobes off and find out. Photographers alter the look of the natural scene all the time. It's silly to call that natural.
Underwater is different in that you always know that ambient light is bad and in what way. You don't know how much. That means that for a given type of shooting, the right filter will be consistently suitable, unlike land. Of course, it won't work if one shot is macro and the next is a pelagic, but I doubt your rig is capable of that anyway. Digital has the advantage that post-processing will always be an option, so if even a filter isn't the best choice, the shot is typically not ruined, just suboptimal.
The ideal filter is one that is the inverse of the filtration effect of the water. That's impossible because water varies in both quality and distance for every shot, but the right category of filters are the flourescents. Flourescent filters are not typically found in a typical photographers gear bag so I doubt you've tried them. A flourescent filter is composed of two elements: a color temperature shifter and a green notch (magenta component). For green water and close up you want more of the second and less of the first. The opposite is true for blue water and long distances. I suggest the Hoya FL-D and the Singh-Ray FL-B for these two cases. I also like the straight CC40M and CC50M gels/resins for just the notch. Avoid the Tiffen versions, though.
Another technique is also valid. For CFWA you may prefer to enhance the effect of isolating color by using a blue filter on your lens and a warming filter on your strobes. I'm not ready to try that yet.
Digital is a great format for enabling experimentation and I hate to see people held back by old predjudice. Filters won't just work by putting one on and shooting as usual; you have to choose the right one and adjust your exposure. If done correctly, they can be yet another useful tool in your ever-increasing bag of tricks.
