The following post about ISF certification is also available for download as a white paper in PDF format. Click here: Playing to the Rods and Cones
Whether sitting down to watch a movie at home, or viewing high definition content at school or work, you want the picture to not only look good—you also want it to look right. If you’re watching “Frozen” with your kids, and they like Elsa’s blue gown, you want to be able to find a gown of that same blue in the store. And if color variations and other issues might affect a medical diagnosis via telemedicine, it becomes more important than ever to eliminate those variations.
You might think this is all obvious, and that flat panels, projectors, and screens show content as it was meant to be seen by its creators.
You’d be wrong.
Playing to the Rods and Cones
The retina is the light-sensing structure of the eye. It contains two types of cells: rods and cones. Rods handle vision in low light and high resolution details, and cones handle color vision—reds, greens, and blues. Cones are very sensitive to even the most minute color differentials—but our cones do not see high resolution or fine details. To trick those rods and cones into thinking an image is brighter, manufacturers have played with the color.
Thus was born the Imaging Science Foundation (ISF).
“We fool the eye things are brighter with blue tints,” according to ISF President and founder Joel Silver. “The problem is, if you accentuate the blue that means you aren’t getting the greens or reds you need to build a color-accurate image. We want to take whatever the artist created and bring it to the screen with fidelity.”
To accomplish that goal the ISF does two things: The organization trains technicians to calibrate the color fidelity and light efficiency of AV equipment, and certifies display products for color reproduction and fidelity.
“We basically tie ourselves into something called a pure white matte screen –a screen that is a reference color,” Silver says of testing projection screens for color performance. “Neutral white … not a hint of tint to it. The picture you get is what was it was meant to look like from the factory … not tinted.”
To be certified by the ISF, a screen has to have a flat spectral response—or color fidelity. In other words, the screen cannot affect the color of the image enough for the human eye to perceive.
Six Draper viewing surfaces—including five surfaces from the company’s exclusive TecVision line—have been certified by the Imaging Science Foundation (ISF) for excellent color reproduction and fidelity.
- TecVision XT1000X White is a premium reference screen surface with a 1.0 gain. It is engineered for blending applications, precise resolution, color accuracy and a remarkably broad viewing cone. XT1000X White performs best where ambient light is controlled. We call this 4K-ready surface a “reference” screen because it is extremely close to what Silver and the ISF use as a “reference” for testing.
- TecVision MS1000X Grey (LINK) has an on-axis gain of 1.0 and performs very well in situations where moderate to high ambient light is present.
- TecVision XT1300X White has an on-axis gain of 1.3 and performs best where ambient light is controlled but projector brightness is slightly lower than desired.
- TecVision XT1600X White, with its on-axis gain of 1.6, performs best where ambient light is controlled but projector brightness is moderately lower than desired.
- TecVision XT1800X White, on-axis gain of 1.6, performs best where ambient light is controlled but projector brightness is significantly lower than desired. XT1800X White is perfectly suited for active 3D or color combining passive 3D systems.
- High Performance XS850E provides precise resolution, high contrast, a vivid color palette, and a remarkably broad viewing cone for superior ambient light rejection, and is recommended wherever room lighting cannot be controlled.
The bottom image shows the kind of color shift that may occur when high brightness projectors and screens are not calibrated for accurate image reproduction. The original image is at top.
What impresses Silver most about Draper’s ISF certified surfaces is the ability of some of the surfaces to deal with ambient light while preserving color fidelity.
“Finding the color fidelity of high gain materials close to that of no gain materials was wonderful!” Silver says. “Gain without a price to pay is a wonderful thing. I knew from measuring luminance even without the specifications that these screens were high gain, but I wasn’t seeing the penalty of color shift.
“It’s a great challenge,” Silver continues. “Adding gain without paying a penalty in color fidelity requires careful engineering. Compliments to the engineer!”
The goal, Silver says, should always be to pairing standards with solutions. Get the end user the best possible picture no matter the room or circumstances. And to best accomplish that, it takes more than an ISF-certified screen.
“With a compliant screen and calibrated ISF projector, the performance will be perfect,” Silver says. “Even without calibration, with a compliant screen and a projector with a good factory calibrated mode, performance will be very good.”
Of course, ISF certification is just part of the screen choice equation. Long gone are the days of size and format being the only screen choices to make. Nowadays, projector and screen technology have advanced to the point that there are different solutions available based on viewing conditions and content. With more factors entering into screen choice, it’s perhaps natural that the one question Silver most often gets is “what’s the best screen?”
“I answer them with a question,” he says. “What’s the best screwdriver? Projector screens depend on the room. Base it on the standards and on the room. Selection of the screen is an interactive process between dealer and end user to make good pictures in good and imperfect rooms.”
Which could pretty much be a job description for TecVision.
And it takes us back to the very beginning. ISF certification of Draper projection screen surfaces means that when you are looking at the blue in Elsa’s gown, deciphering a medical image, or trying to determine the color of a suspect’s eyes via security cameras, there’s no need to “let it go.” You know you’re seeing what you’re supposed to see and what you want to see.
Real colors. Tuned perfectly to your rods and cones.
For more information on the Imaging Science Foundation, you can check out their website here.
To learn more about Draper’s TecVision Engineered Screen Technology, click here.
