Blue Filters on Lights?

[The Publisher]

Oh, I have an Amphibico Phenom housing, and I always use lights unless shooting wide angle, at which point I white balance against a warming slate, then drop down the red flip filter as needed.

It did cross my mind that the red filter blocks light.

The guy who owns Gates, I went up in his Cessna airplane and we flew around for an hour fun-good guy.

[klemens Gann]

If you have the lights on, using a red filter in addition doesn't seem to make sense to me!?

[The Publisher]

Oh, the Light and Motion lighting concept with a blue filter on the light and the red filter always on is when you are shooting macro up close, the blue light and the red filter balance out for proper color rendition, objects in the background that are not illuminated appear with more red added.

Their whole idea is when you shoot a clip with subjects both up close and illuminated and far away and not illuminated, the colors will be more evened out, instead of the traditional up close with lights on, good color of stuff up close, but subjects far away ALSO in the clip will be their usual all blue.

[nautilusvideo]

Or maybe the best thing is to do is white balance underwater as needed. If you are using HID/HMI/5600K/Daylight lights (which you should be) then in the end this is the best solution.

Adding filters to camera lenses or to lights drops the light output by at least 1-2 F-stops and we all know that our HD u/w cameras need light and lots of it.

In the above water world when I'm shooting for Discovery, Nat Geo, etc. we balance for out light source (the sun, HMI's, tungsten, etc.). I may use a warming card but that's it. The same principles apply to lighting and white balance underwater with the caveat that it takes a lot of light to do almost everything. Shooting u/w always involves compromises and adding filters and gels doesn't substitute for good technique and quality control.

[ronscuba]

Almost all my diving has been clear tropical in the Caribbean, so my comments below are based on that.

My FX7 has an auto gain limit. Currently I have it set to 6db. That pretty much takes care of the grain issue. I use a filter for wide angle since my lights are not strong enough to fill a W/A shot and MWB is easier to set with the filter in place. Many times I can't get a MWB lock w/o the filter if I am deeper than 30 feet.

If the scene looks too dark with the filter, I'll flip it out.

Lights for macro shots, no filter.

One scenario where I use filter and lights together is late day shooting. I set MWB with the filter in place and lights on. The result is the foreground and background are both nicely colored. I learned this "trick" from Annie Crawley's DVD.