"When working with HDR, I recommend a minimum of 100 nits measured off the screen after calibration. What about resolution? The higher the resolution of the projector, the higher the resolution of the screen needs to be. For example, if speakers are going to be placed behind the screen, you need to consider the potential light loss of a perforated screen or the reflectivity of a woven screen. "The projector, room, sound system, and the client's preferred viewing habits affect the choice of a screen material. I recommend trying to achieve 30 fL (approximately 100 nits) of peak light output for HDR in a front-projection system."ĭavid maintains that the best screen depends on several factors. In the best of all possible worlds, unity gain (1.0) will give you the best performance if the projector has enough light output for HDR. "I generally recommend a gain no higher than 1.3. "Also, it is not advisable to use a high-gain material," he continues. ALR screens usually cause a color shift, and they sometimes adversely affect gamma. That is far from ideal for either HDR or SDR. "In my opinion, the only good application for that type of screen is when the user plans on viewing with ambient light in the room much of the time.
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I've heard some say that a high-contrast ambient light-rejecting (ALR) screen is best for HDR, but Kevin disagrees. In a front projection-based home theater, the room is part of the system if it is light, it will minimize contrast, and if it is dark, it will maximize contrast." Screen
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Light walls or a light-filled room decreases the contrast of the system. In a front-projection system, light travels through the room itself, so the room is a huge part of the performance. HDR projection looks great in this room! (Photo by Scott Wilkinson)ĭavid agrees, adding, "A flat-panel display is a closed system where external factors don't affect the performance of the display, but rather our perception of the display. 1: This is an example of the ultimate projection environment-completely black. Of course, colors also get reflected onto the screen." Fig. A combination of black and medium to dark grays throughout the room is ideal for the best experience and performance from any front-projection system (see Fig. A black screen wall is ideal, because it will absorb any stray light being reflected. "Light-colored surfaces reflect light from the projector onto the screen. Kevin points out that the color of the room is equally important. Ambient lighting can have a large effect on display contrast and can wash out the image when viewing darker imagery, so getting the room in proper condition for viewing goes a long way." You want to be able to control the conditions as much as possible to get the best presentation.
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As Kris says, "Room conditions are largely the same for HDR as they are for SDR. EnvironmentĪ completely light-controlled room is critical for the best HDR performance. Then, come back here to learn what you need to know to get the best HDR performance from your projector. If you're not up to speed on the whole subject of HDR, I recommend you start with my article " HDR From A to Z".
Spears and munsil gamma calibration how to#
What does that optimization entail? I asked three distinguished calibrators for their thoughts on how to obtain the best possible HDR picture quality from a projector: David Abrams of Avical, Kris Deering of Deep Dive AV, and Kevin Miller of ISFTV. Will it look better than SDR from the same projector? Absolutely, as long as you optimize the room, screen, and projector settings. Will it be as bright as a flat panel? Certainly not. Given that reality, is it really possible to get a good HDR image from a projector? I say yes, though some experts wouldn't call it true HDR, but rather "extended dynamic range" (EDR), which lies somewhere between SDR and HDR. And yet, many projectors today tout their ability to accept and display HDR content. Projectors have a much lower peak brightness, and only the best have black levels anywhere close to that of a good flat panel. At least, it is on modern flat-panel TVs, which offer a huge range between their peak brightness and black level.