Q. How do I use the colors on a DSC chart?
A. For accurate reproduction of a scene, position the color signals produced by the DSC chart into their respective vectorscope boxes. This can be done either before a shoot, or if you shoot a few frames of the chart on the set, later in post production. For optimum quality, DPs use both methods, because the less correction that has to be done in post the better, both for image quality and your pocket book. While post production invariably offers greater image adjustment capability, it is always best to start with accurate reproduction of a scene.
Setting up a camera before a shoot involves first aligning a cameras gamma and tracking using the chart’s grayscale. Next, set up the cameras’ matrix to position color signals in their respective vectorscope boxes. Some cameras have limited adjustment capability which is why you shoot the chart on the set for further color adjustment in Post.
The narrow tolerances of DSC charts give users a higher level of confidence in knowing that placing color signals in the boxes should result in accurate color reproduction. While accurate reproduction is a common goal, many clients use our charts to create a unique look. You can always try to reproduce the look later by saving a scene file, but this does not always work under lighting having different spectral distribution. The better way is to shoot a DSC colorbar chart under the look you made and record the waveform and vectorscope readings. Later using the chart under different conditions you can replicate the look by matching the waveform and vectorscope data. Obviously it is important to record lighting angles and relationships; the Billups or DSC VFX patterns are very useful in providing this data.
Making grading decisions with the naked eye is a risky business, requiring both a perfectly calibrated monitor and the proverbial golden eyeball. This should rule out eye-balling color correction and scene-to-scene matching on your laptop. However, with a DSC chart and color and waveform data to complement your NLE, you can make intelligent grading decisions even on a laptop. - Q. All grayscales are the same, right?
A. This is not true - of all the charts we have measured; only DSC grayscales are neutral from white to black. Others are typically 14-35mV (2 to 5 IRE) yellow at the white chip, mostly becoming more neutral towards black. Aligning to a yellow chart will produce bluish, cold-looking images. Other problems; some charts have high infra-red reflection in the black and darker chips which can play havoc with grayscale and color reproduction in some cameras. Obviously aligning to such grayscales will produce inferior images. - Q. Do you suggest that using a DSC chart will save me time and/or money in post?
A. That’s what many users tell us. Eyeballing the color correction (grading) process takes time and is subjective. Recording a precision DSC chart when you change lighting or location helps you lock in color consistency, not just this week, but year-in, year-out. Many networks have been standardizing image quality with DSC test tools for more than 30 years. Some operators are partially colorblind, but still make great color pictures going by the numbers. - Q. Some test charts cost less than DSC’s; what’s the difference?
A. Briefly - Engineering, Patented Technology and Precision - these are built into every DSC pattern.
Anyone with a computer and a $75.00 printer can make test charts for pennies a pattern, but such charts can create enormous problems. Misaligning cameras to inaccurate test charts can be an expensive decision, not only ruining a production, but also people’s good reputations.
Our users rely on the consistency and precision of DSC products and, despite increasing production costs, we have been able to hold present price levels through increased volume. To produce the quality products our clients need requires ongoing research and constant testing of media, pigments and other materials. Depending on the model your ChromaDuMonde charts are measured in as many as 288 places and calibrated before a chart is deemed to be a Pass. By using less expensive substrates and batch calibration for some of the charts (FrontBox Series, Camettes, etc.) we are able to offer products which fit within the budget of even small productions. - Q. Your charts have a glossy finish; can that be problem?
A. Very rarely - the benefits far outweigh the potential problem. DSC’s unique surface significantly increases both grayscale dynamic range and color saturation. An important side benefit is that these charts really take a beating and can even be washed when they get dirty. Some clients even use DSC charts for deep sea diving, and in the space industry.
We do make hybrid matte charts for a couple of the network soaps, aligning many cameras at the same time. Like all matte charts, they are easily damaged, have flare issues and can generate less reliable information. For the other 99% of users, the benefits of our high gloss finish far outweigh the occasional inconvenience. - Q. Do more people use your charts to reproduce colors accurately, or to create a look?
A. We find that most broadcasters, rental houses and service shops set up for accurate color, while those shooting for film output develop a look for each individual project after first setting up to 1:1 accurate reproduction. - Q. I’ve always set-up cameras to a grayscale chart, but my dark tones seem to be crushed and don’t have the deep tones seen on network shows?
A. This is a common problem with traditional front-lit test charts. To hide reflections, manufacturers use a flat matte surface on their charts and this diffuse surface results in varying degrees of flare. Dark tones are particularly affected. For example, 2% surface flare has a minimal effect at the white step, but because the black step should only be reflecting 1% total light, the 2% flare results in an error of 200%. DSC's CamAlign Charts address this problem as discussed above, the laminated surface increases dynamic range and color saturation, and prevents surface damage. The dynamic range of matte surfaced charts is a particularly relevant issue in HD applications. - Q. What size chart should I buy?
A. Unless you are shooting in very large venues (a church or sports stadium, for instance), select the largest chart you can comfortably carry around. Ideally, placing the chart where your talent (or subject) will be, you should be able to zoom in without going to the far end of the zoom. Try not to use the far end of the zoom, because that is not where lenses perform at their best and there will likely be a shift when you zoom back to your actual framing. As a guide, our Senior Wide chart, 24 inches wide, was designed to be used at a distance of ten feet. - Q. Which chart is your most popular for HD production.
A. Our number one seller is the ChromaDuMonde28R (24 colors with 4 flesh tones, Resolution trumpets and CaviBlack). Second place goes to the ChromaDuMonde 12+4R (12 colors with 4 flesh tones, Resolution trumpets, with/without CaviBlack). - Q. I have an HDV camera; which chart is best?
A. Some feel that a $1,000 chart is overkill for HDV cameras; FrontBox charts cost considerably less, come in a variety of patterns, are double sided and feature a backfocus pattern on the rear. - Q. Is it worth it to spend the extra money for the CaviBlack?
A. This depends on what you will be shooting. In HD the answer is normally yes, its the best way to get closest to absolute black. It helps to get maximum dynamic range from the camera, very important in achieving good shadow detail. If you’re working in standard def SDI, then the CaviBlack is also useful; for good old NTSC the benefits are debatable. - Q. You put a recommended upgrade date on your charts, why and how long will they last?
A. The purpose of the upgrade date is to protect both our clients and our reputation. While every effort is made to provide long life to the charts, there is no way of knowing the conditions to which the charts will be subjected. While it is rare, one DPs chart turned yellowish after it was stuck in the X-ray machine at Customs for a long period, he estimates about an hour. - Q. Do you have trade in offers?
A. Yes, we have several trade-in offers to suit the different needs of clients. We have always encouraged the recycling of DSC charts and provide various discount levels as follows.
10% Discount Applied to purchase of new DSC patterns with trade in of other manufacturers’ test patterns.
15% Discount Applied to purchase of new DSC patterns with trade in of DSC test patterns.
35% Discount for clients who automatically replace their charts annually with the same DSC models.
50% or higher Discount for clients who wish to use EcoAlign, DSC’s subscription program that ensures both automatic recycling of old charts while providing clients with replacement patterns every year. - Q. If I align to a chart and then white balance on the set, is this the best I can do to make good color images?
A. Not necessarily, if for example the lighting director has lit the scene for a moonlit look, white balancing the set will totally kill the effect he is trying to produce.
There are two solutions:
White balance on a DSC colorbar/grayscale chart lit with the same type of illuminant that is used on the set, but without filtration,
Do as many network shows do - use a portable Ambi/Combi rear-lit system for camera set up and white balancing. This is very handy as the Ambi can be wheeled around the set and is always ready for use. Note: virtually all modern cameras can be white balanced to a ChromaDuMonde or other DSC color pattern, because the color chips collectively are in effect neutral. - Q. Why should I white balance to a DSC Pattern when I have access to printer paper, or a white wall?
A. A common mistake is white balancing to a perceived white rather than a true white. Few papers are truly neutral being typically blue or yellowish. White balancing to these will induce an undesirable false tint to your images. DSC’s CamWhite is a spectrophotometrically neutral and White n Warm provides both a true white along with DSC popular image warming card.
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