Color Facts

Version 7.5 was first introduced in 2008 at the Integrated Systems Europe (ISE) trade fair in Amsterdam and is the current version of calibration software that, on the one hand, is intended as a calibration tool for all kinds of display technologies and, on the other hand, serves as an evaluation tool allowing you to check particular properties of various electronic display devices.

Just as with the Spyder3TV, the package includes the new Spyder3 sensor, which, when connected by USB to a windows PC or laptop, can be applied to the measurement of a variety of monitor properties, such as color accuracy, gamma, color temperature, grayscale linearity, brightness, contrast and many others. Contrary to many purely software-based solutions, CF is a non-proprietary software solution (i.e. it does not only work with same-brand devices), allowing you to use it with professional measurement devices from other manufacturers such as Minolta or Photo Research. This is particularly important, as not every sensor can be used with every kind of display technology.

The Spyder3 sensor is still a good entry-level device for the world of professional display calibration, but Datacolor has left the door open for any users gaining in know-how (or whose applications are changing) to use the CF software in combination with an even higher quality sensor. It's no wonder therefore that ColorFacts has become one of the most frequently used calibration tools within just a few years.

It is used equally by home-theater installation engineers, calibration specialists, technical editors and even private home-theater enthusiasts. As well as its comprehensive compatibility with measurement sensors, CF supports various test pattern generators from firms such as AccuPel, Extron, Quantum Data and Sencore. These devices feed the test pictures required for measurement directly into the display being calibrated and can be controlled from the PC or laptop, using an RS-232 cable.

ColorFacts allows measurement of color space, color temperature, grayscale linearity, gamma, brightness and contrast, among others.

Before calibration, the user must inform CF which sensor the measurement will be carried out with, and using which source (a test pattern generator, the graphics card of the PC or an external DVD player) the test pictures will be delivered to the screen.

Similarly to the game "Battleship", each color and white point was given an x and y coordinate, which allowed precise localization of each hue. This is necessary because humans all judge color subjectively, and an objective definition of color is only possible mathematically. The CIE 1931 chromaticity diagram was therefore the research basis for the modern television, and served as a reference for electronic picture reproduction devices, defining which color spaces and color modes they should be able to display in order to give a standardized color reproduction.

The color space of a display is defined by the chromaticity and saturation of the primary colors red, green and blue as displayed on the monitor. When these three points are connected with straight lines, a triangle is formed that is known as the "Color Space".

All colors within this triangle can be reproduced by this display, whose three primary colors should ideally conform to the prescribed color standards. These color standards are defined by official bodies such as the  ITU (International Telecommunication Union), the SMPTE (Society of Motion Picture and Television Engineers) and the EBU (European Broadcasting Union).

The "horseshoe" CIE 1931 diagram served as the theoretical basis for the introduction of color television.

The three modern color standards EBU (PAL), SMPTE-C (NTSC) and HDTV all describe different color spaces.

CF is therefore a monitoring tool that on the one hand allows the color performance of a display to be checked, and on the other hand can also be used to carry out corrections to the color space - this is of course only possible to the extent that the display being calibrated allows access to its color processing settings.

Before measuring the color space, the software is told which reference to compare to - HDTV in this case.

Particularly in terms of the green measurements, this TV is nowhere near the correct value.

This display has a color grading whose primary colors can be almost exactly matched to the HDTV color space.

ColorFacts offers the option to determine the gamma characteristic of the display by measuring various grayscales, and then to represent this as a graph corresponding to the display gamma of the monitor. The gamma curve can then be displayed as a single line, which describes the brightness response from black through to white, or in the form of three lines, one each for red, green and blue, which describe the relation of the primary colors to each other in terms of gamma.

The pink line gives the display gamma in the form of a line representing the sum of the RGB components.

In this representation, the relation between the primary colors (RGB) is shown, which should ideally give a color temperature of D65 (6,504 Kelvin) at all brightness values.

The possibility does exist to set the reference point in CF prior to measuring the color temperature, so that the subsequent measurement can be compared with the correct reference value. The results can be displayed as either a colored bar chart or as (x, y) coordinates. If the monitor's color temperature is incorrect, and the display manufacturer has allowed it to be adjusted, ColorFacts is the ideal tool to help adjust the monitor's white representation to the D65 reference point.

Prior to measurement of the color temperature, ColorFacts is told which "reference white" is the target for the color temperature setting.

If the calibrated color temperature corresponds to the reference value, the RGB bars will all reach 100%.

Inputting the coordinates directly is significantly more precise, allowing the color temperature to be set to four decimal places.

The foot-lambert is of interest above all for determining the total picture illumination of a video projection - this is still frequently measured in foot-lamberts (fL) and is essentially more important than the ANSI Lumen rating of the projector. This is because the fL measurement relates to the brightness on the projection screen, which is an important factor in the movie theater. The foot-lambert value varies depending on the size of the picture, while ANSI Lumen values do not, as their measurements always relate to one area in particular.

The "Options" menu contains the setting to choose between the metric and imperial forms of the measurement results, and there you can also select which sensor and test pattern generator will be used. The grayscale linearity - as with the gamma - can either be displayed simply as a line, or in the form of three separate RGB plots. These then help to visualize the relation between the primary colors which - in the long run - makes up the color temperature, or the "color" of white.

ColorFacts Professional provides many more options, which we will not discuss here as this would clearly go beyond the scope of the article. Those who are interested are recommended to attend a training session after purchasing the system, where the methods and possibilities of ColorFacts will be discussed in greater depth, enabling you to get the best performance out of the calibration software. For more information on the training sessions offered by Datacolor, see www.datacolor.eu/jkp. Training sessions in other locations - and in English - can always be arranged.

The grayscale linearity can be displayed as the relation between red, green and blue.

The contrast wizard allows measurement of a monitor's full-on/full-off contrast.

Various parameters can be defined in the "Options" menu, for example whether the values are displayed in metric or imperial units.

With its comprehensive sensor-compatibility, the CF 7.5 is an ideal tool for all display calibration applications - the possibilities are more likely limited by the display, the operator, or the sensor being used, than by the software. While Spyder3TV provides the private user with a simple picture optimization solution, ColorFacts Professional 7.5 is a professional tool, which in the hands of a trained user, allows the best picture to be extracted from any display device.

"Order here" ColorFacts in the EU and in the US.

The Televisions.com test laboratory, AV T.O.P. Messtechnik, uses ColorFacts Professional in its TV tests. It is, on the one hand, a professional system and, on the other, a user-friendly, graphically interesting system for color measurement and optimization. For truly precise measurement, however, particularly in terms of the color space, the Datacolor sensors are not sufficient. We use Minolta's high-precision measurement devices in order to give accurate results even at low brightness settings and with large color spaces.

That said, if the desire is for rapid picture optimization using sensors, it is ColorFacts every time in our eyes, even though there are a few extra functions and capabilities we would like to see introduced. Spyder3TV is a very much simpler system, which can at the very least help to adjust the most important settings, and is also well-priced for the typical private user.

One fundamental point still stands - if you want professional picture optimization, you need to hire a professional. Even the best calibration tools are no substitute for the experience of a calibration expert. To be fair though, even the pros are lost without a system like ColorFacts.