Dive Dry with Dr. Bill

#244: Light the Way... Please

I was a land-based still photographer and videographer for many years before I started shooting the undersea world. I did try my hand at underwater still photography in 1969, but didn't have the skills (or the budget) to do it effectively. I've had many years of experience lighting subjects like Catalina's native plants, as well as pretty women models (fully clothed... of course). Imaging underwater is a different issue. While many of the techniques used by land-based photographers apply underwater, there are substantial differences requiring new skills and equipment.

Water absorbs light, so as you go deeper there is less of it to create a satisfactory image unless you use an underwater strobe or video light. Even down at 200 feet, I often have enough light to record a video sequence. However, it is not enough to create a sharp image that shows the detail in the subject. I was on my first dive on a beautiful Sunday morning at Sea Fan Grotto, and had dropped down to 150 feet to film sea pens. Now these stationary relatives of jellyfish and corals are essentially white in color. However their feeding polyps are very small and require good lighting to bring them into sharp focus.

I settled on the bottom to remain steady as I filmed, and twisted the lamp head on my video light to turn it on. Nothing. I twisted and turned the head repeatedly to no avail. It just wasn't going to work. Not wishing to remain at depth without something to film, I slowly ascended to shallower depths, stopping at 100 and 60 feet for safety before heading to about 20-30 feet where I would stay for the rest of my dive. Just as I started up, I noticed a diver's light sitting on top of a rock. Assuming it was from one of our divers, I attached it to my wrist and swam up towards the cave.

Once inside, I explored the cave for a bit, but couldn't film anything without my video light. Then I saw it... a very large moray eel moving its head about in the gloom of a shelf on the cave wall. Darn, no light to capture this monster and bring it back to my cable TV show viewers. Then I thought... why not try the dive light? So I did. Since dive lights have focused beams rather than the softer, diffused illumination from video lights, this created some harsh lighting, but at least I was able to capture the moray on video tape for my TV program.

When I returned to the King Neptune, I discovered there had been a tiny leak in my video light... just a few drops. However, it was enough to knock out the electronics in the $400 light. I knew the manufacturer no longer stocked parts to repair them, so I was "out of business" until I can afford a new set of lights. There was good news... for someone else. The dive light I found did belong to one of the folks on board, and he was quite pleased that I had retrieved it since it was brand new.

I did two more dives that day, but with no video light I captured little footage for my TV show... or for this newspaper column. That meant less footage to edit that night... always a silver lining. I knew I had to replace the video lights soon if I wanted to continue gathering footage, but I was painfully aware that my budget didn't really permit that... unless the bank would forgive a mortgage payment or three. I was sure they would... just before they foreclosed on my home!

That brings me to the second aspect of light in the marine world. Not only does water absorb light and create less of it at depth, it also selectively filters out different wavelengths or colors. The first colors from the sun's spectrum to go are the lower energy reds, oranges and yellows. Even at depths of only 30 feet, video lights may be required to supplement sunlight and bring out these colors. Greens and blues are filtered out last. This is why underwater footage at moderate depths in our waters have a bluish or green cast, although the green can also come from plant plankton. This is also why deep alga are often red in color... they absorb the more abundant blue and green light for photosynthesis instead of reflecting it back like green chlorophyll would.

My dead video light was similar to the incandescent bulbs you have at home. It had a yellowish cast to it. For some time I've been thinking about upgrading to the newer High Intensity Discharge (HID) video lights which are brighter and bluer in color, and more effectively bring out all the true color in our marine critters. What was stopping me? The fact that these lights can cost $3,-4,000 a set. I don't receive any money for my cable TV show (nor should I since it is on public access). I do it as an educational service to our community and our visitors, showing them the wonders of the waters surrounding the island in hopes my viewers will grow to love them as I do.

Therefore there is no revenue to acquire the new lights. Ah, the life of a starving marine biologist! However, I am working with a manufacturer who may be willing to give me a better deal in view of the educational purpose behind my filming. Until then, continue to enjoy the many existing episodes of my cable TV show. I'll be making new episodes, too... but you'll be green (and not with envy) as you watch them! Of course non tax-deductible donations are always welcome!

© 2007 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays. Please help me climb out of self-imposed poverty... buy my "Munching and Mating in the Macrocystis," "Great White Sharks of Guadalupe," "Calimari Concupiscence: Mating Squid, " "Playful Pinnipeds: California Sea Lions," "Belize It or Not: Western Caribbean Invertebrates, Fish and Turtles," "Gentle Giants: Giant Sea Bass" or "Common Fish and Invertebrates of the Sea of Cortez" DVD's. Yes, take Dr. Bill home with you... we'll both be glad you did!

A sea pen like I had planned to film, my dead video light; the dive light I discovered on the ocean floor
and the big moray filmed inside the cave with the dive light.

This document maintained by Dr. Bill Bushing.
Material and images © 2007 Star Thrower Educational Multimedia