Shooting Underwater SCUBA Video
Light wavelengths: You start losing red at about 20 ft., orange around 30 ft., yellow at about 40 ft., green at about 65 ft, and blue at about 90 ft. Light and color absorption increase dramatically at depth. As a rule, ambient light decreases by 50% for every 33 feet of descent. Of course there are variables like the visibility factor when there are high levels of phytoplankton in the water column, etc.

 

William Barrett (MoovyMagic-at-aol.com):
Well, you're not GAINing blue, so much as losing everything else, longest wavelengths first. This may seem a silly distinction, but it's not, because you have to restore more than just red.

We designed and purchased our personal equipment to help things a bit visually. The divesuits are a bright royal blue. The fins black, the Old Classic, Jet Fins. (The eye is less drawn to them than to white or to weird fins like that backwards snappy thing) The home-designed and built BC's are back-mounted and light grey. Point being, right off the bat we only need worry about color for non-diver subjects. Yellows and reds in personal equipment get to looking UGLY and muddy pretty quick, even pretty shallow. So, since it's all gonna shift blue anyway, it'll be a more pleasing color if it's blue to start with. I also think it's a classy, timeless look compared to all the silly electric trendy hotsy-totsy dayglo colors so common in today's gear.

There is a filter around called the UR Pro. It isn't red. It's a strange amber-but-not-quite-amber color to look AT. I guess I could say it's like Bloo-Blokker sunglasses to look THROUGH. If the camera is left on auto-tracking white balance, the UR filter seems to not do much in shallow water to about 15 feet, where color renditions are very good, except for large horizontal distances. The filter seems to come into its sweet spot from maybe 20 to 40 feet or so for "normal" carribean-style clear water. It's quite useful down to maybe 80 feet, and beyond 80 feet, there simply isn't ANY long-wave light, no matter HOW much differential gain you provide.

We rarely light underwater. It just creates so many problems in the distant objects going solid blue, because the ones close in to the lights are driving the tracking balance more towards the normal range. We rely on God for the lighting, and the UR Pro to tidy the specrum up a bit. Reflectors to re-direct penetrating sunlight work better than you would think. Weirdy enough, I've actually tried blue-gelled underwater lighting to get intensity for a foreground subject, but surrenduring to the inevitable and unlightable distance effect as the dominant effect. It worked amazingly well! Try it!

We've shot with single and triple-chip cameras with the UR filter and without, and on auto-tracking white balance, and it's mostly looked pretty good. If you have access to the manual white balance button underwater, you might try going to fixed manual, and then forcing a fixed balance. But the question then becomes white balance on what object, and at what range? That's not so simple a question as when topside. I think auto-tracking's the right answer. The question is then one of what camera is most adaptive in tracking range, not just the chip count. Having said that, the extra sensitivity of a single chipper (no optical splitter block) gives you more intensity headroom for the tracker to track within.

Finally, we always do some color correction in post. We've tried red gain, and an all-over red wash or a red-yellow wash from the switcher, and to my eye a little overall wash from the switcher adds a nice look if not overdone. Just a little. Now, nothing says you can't add optical filters external to the underwater housing. So if you determine by experiment a best filter for various depths, you could change on the spot. We haven't done this......yet.....but it seems a fertile ground for experiment.

Safe diving... And never forget underwater photography has proven to be statistically one of the most dangerous underwater activities. For three reasons:
    1. One carries a lot of gear in addition to the regular dive gear. Adds complexity to the workload.
    2. It's expensive gear, and you'll risk your ass to save it, where you'd just let a knife or a weight belt go.
    3. Photography dominates your mind. Your situational awareness goes to hell when you're pre-occupied with fiddly fussy bits instead of thinking about BREATHING AND STAYING ALIVE.


The only time I ever got bent was in a POOL, when I wasn't thinking about the diving, but the shooting. What could happen in a pool, for God's sake? Two things. (And maybe others) First, photographers develop the nearly subconscious habit of holding their breath while shooting. Fine, unless you're ascending underwater when it can easily cause stress hyperinflation and rupture of a lung. Doesn't even hurt till the embolism hits. Believe me, this is a LOT easier to do than one might think. Especially in shallow water, where a four foot ascent represents a greater percentage of pressure change than it does at fifty feet or more. Since so much photo shooting is done in shallow water--especially when in fresh water lakes, it's a real consideration. Or you can go to the deepest part of the pool, 12 feet in my case, and shoot and surface to consult, and then do it all again maybe thirty times, trying to catch that perfect springboard diver's water entry in a dramatic straight-up point of view from the bottom. Well, the dive tables don't count dives under 16 feet as building up ANY nitrogen for you to have to blow off. You don't need to de-compress gradually, but you DO gain some nitrogen load, even at 16 feet. But the dive tables don't consider so very many up and down cycles. Turns out such an extremely weird profile puts one way off the charts. I didn't get hurt, but I got real woozy and stupid for a while.

Some say I never got better...............

bb (The Only Certified Diver Ever Reported "Bent" In A Pool.)

 

 

Betty Wills (betwills-at-airmail.net):
As a dive master, one of the things I stress most during my u/w photog classes is SAFETY FIRST. I also run students through a series of buoyancy skills at pool before we ever hit the open water, and I emphasize employing a good buddy system. I realize solo diving is the newest fashion, but for photogs, it ain't kewl. I had an excellent assistant on this last trip. To begin, he's a dive instructor so he was very conscious of what I was doing. He kept the gauges read, carried my camera on the descents and ascents, and saved my butt when I lost my weight belt at 115 ft. I was laying across a rock shooting white tips and marble rays, when the buckle on my weight belt hung on a jaggy. Before I realized what was happening, I was already floating up. He reacted instantaneously - I was still shooting - and grabbed me and the weight belt at the same time. There's nothing like experience is there?