DSC COLOR CHART for PROPER WHITE BALANCING
This photo was taken in the early 2000’s when Tom was using the Sony F900 High Definition camera in the Amphibico housing. He pioneered the use of HD underwater and amassed an extensive footage library of HD tapes shots around the world.
The footage was always properly white balanced because, before shooting, Tom ensured he used the DSC Labs color chart with the lights, and at the depth, he was filming. When that footage went into the professional edit suites, it rarely needed any color correcting because the DSC chart allowed Tom’s white balance settings to be perfect!
DSC charts are used throughout the TV and film industry and are considered the Hollywood standard. DSC develops cutting edge technology that helps clients produce consistent optimum quality images. The charts are used not only used in television and motion pictures, but also in Law Enforcement, Medical and Security applications. David and Sue Corley started DSC in their basement in 1962 and have grown the company into the world leader with their charts used in every environment on land, in the sea, and even in space!
Tom wrote the following article about his use of the DSC chart, and why it is critical for proper white balance, when he was filming with that Sony HD system. His reasoning holds just as true today, even in the world of digital cinematography:
UNDERWATER COLORIMETRY
As a marine wildlife cinematographer who spends much of his life in, around, or under water, I confront a number of challenges that are not so common to those faced by topside cinematographers. Those of us who shoot underwater or topside anywhere around the ocean encounter more precarious situations with regards to caring for our equipment. We also experience a wide variety of lighting issues that must be learned in order to get top quality images of marine wildlife.
Paramount to capturing precise color match and exact contrast in the marine environment begins with acquiring the correct and most accurate white balance. Color saturation is totally altered with the bending of light rays as they enter the water column. The amount of light is again affected by the amount of turbidity or particulate matter in the water. Features such as wave action on the surface, clouds in the sky, and other issues further alter color saturation.
As you descend deeper below the surface, the lack of light coming into the water column dramatically affects the color spectrum of brighter colors such as reds, greens, yellows, etc. In the first few feet of depth, bright red objects start to lose their true color and become a drab brown by the time you reach 30 feet or more. Orange and yellow colors drop off next as you approach the 60-foot depth. Blue can be distinguished to 100 feet and greens fall away too, until – eureka! You’re left with a very monochromatic and drab looking topography with dull-colored fish life that wouldn’t capture anyone’s interest for long. If you cut yourself underwater or you spear a fish at these depths, the color of the blood will appear green rather than red.
It’s not just vertical depth that causes this effect: once you’re at the depth you have chosen to shoot the horizontal distance also causes loss of color. For example: A diver shooting in just 10 feet of water with a subject 10 feet away will have filtered out nearly all the warm colors because the light now has to travel 10 feet down and 10 feet out which equals 20 feet. Horizontal color loss is the reason that underwater lighting systems are not very effective if not used properly. Most strobe or constant lighting systems will reach out 6 to 8 feet effectively but offer very little illumination beyond that distance. So the photographer at 10 feet of depth and l0 feet from his subject is going to get little to no color because not many lighting systems will reach out 20 feet. Whenever you see an underwater show that has brilliant colors in it you can generally assume it was shot either with lights of some sort or the perfect white balance chart.
Is there no hope? Yes there is: In working as a professional underwater photographer and cinematographer for more than 40 years, I have learned many things about lighting, both from the years of experience (the hard way!) and from other experienced shooters in the same field. My crew and I may have a bit of an edge on High Definition work in the water considering that we switched from film to HD in 1999, long before HD became a household name.
For us, the answer to getting perfect color saturation both topside and underwater with our cameras is to use the correct DSC Labs color correction chart. While many models of the chart are available, a few of them suit our specific needs: a small waterproof one is perfect for underwater use, a larger one for topside work with our Sony F900’s, and a new version specific to the RED. The DSC Company has pioneered the field in establishing the exact mathematical formulas for their DSC charts by using spectrophotometers and waveform vector scopes. They have established precise white balancing charts to match color combinations to achieve perfection in producing correct colors.
The old days of pulling a white balance off of a white plastic board, walls and t-shirts are pretty much left to history, or amateurs, as it may be. If you consider any other source of white balance, you are paying the price for manufactured materials that have any number of UV inhibitors built into them, which will throw color off considerably. In fact, white boards or other white-colored materials will generally give an IRE (incandescent ray emulsion) reading of somewhere around 8 or 9, as compared to the proper chromadumonde chart, which will give about 100 IRE. The IRE is a direct relationship to the color saturation – the higher the IRE value, the truer the color saturation.
Therefore, choosing to use a DSC chart over a white card is not rocket science for us! Considering that everything we shoot is in HD or greater lines of resolution (to allow for the most vibrant and real life colors possible) we simply cannot afford to have anything less than perfection in today’s competitive work place. In fact, with our switch to RED digital cinema formats, we continue to rely on our DSC chart. Contrary to popular belief, RED camera users are not exempt from this procedure. DSC has created a specific color chart for RED users. Shooting RAW allows digital media to be manipulated in post, but that consumes both time and money, so it makes much more sense to shoot with proper white balance from the get go.
When white balancing underwater, we try to get as close to the chart as possible, to avoid the problems of refractive light loss as mentioned earlier. We fill the frame with at least 70% of the chart with an equivalent light source in which we’ll be shooting, in order to give us the best saturation and precise color match possible. For underwater menu settings on our Sony F900R we had a UR-Pro filter installed in the color wheel in the ND-4 position by BandPro in Burbank, which put a tad more red into the mix if needed.
It is important though to re-white balance as you descend deeper to take into account the continued loss of available light, especially if you are not using an alternate light source.
Whether shooting with our powerful Keldan lights, whether for large subjects and wide-angle shots, smaller lighting systems for macro work, or natural ambient light with no artificial lights, we are faced with the challenge of obtaining the correct white balance. Using the DSC chart to white balance for each situation (and checking the white balance with our chart underwater) allows us to achieve stunning results.
The true kaleidoscope of colors found beneath the sea are far more impressive than those found anywhere else on earth and only through proper white balancing can they be captured in all their brilliance.