Stewart Filmscreen Phantom HALR
High Ambient Light Rejection projection screens

When choosing a projection screen, take care to consider carefully the environment in which it will be used. With the right screen, the difference can be night and day...

The pictures shownin this article are undoctored images of a demonstration projection screen put together by Visual Fidelity, the Australian distributor of Stewart Filmscreen. As you can see, it is made of two different projection surfaces spliced together in the middle, illuminated by the same projector.

So what do you think? Which image would you prefer to see in your home? The left side is colour-rich with respectable blacks, while the right side is washed out and in some cases barely visible. We’d all pick the screen surface on the left. Right?

Night and day
In fact, the surface on the right is the choice of professionals — it is Stewart’s premium matte white surface, SnoMatte 100. This is the material used as a de facto standard by most Hollywood studios, post-production houses and colour-timing facilities — the reference quality for imaging professionals seeking critical colour matching and image quality.

So what’s going on in the pictures here? The answer, clearly, is ambient light, the bugbear that keeps bigscreen projection out of so many locations, even though the screen sizes available for front projection easily trump even today’s ever-enlarging televisions in terms of delivering truly cinematic movie entertainment. Today’s projectors are cheaper than ever, more advanced in their resolution and connectivity, brighter, even longer-lasting as LED light engines supplant the traditional lamp-based light sources. But you do still need a dark or at least darkened room, whether that be a dedicated windowless home cinema, or a lights-dimmed lounge. It has to be movie ‘night’ — you can’t enjoy a morning flick or an afternoon sports game, because ambient light will wash most of it away.

And that’s what is shown here. These photos were taken in a meeting room with the overhead LED lights on and daylight streaming in. SnoMatte 100 (on the right) might be “the world’s most accurate projection surface”, but as with all matte white type projection surfaces, it will readily wash out under moderate to high levels of ambient light.

Phantom HALR
The screen surface on the left, then, is Stewart Filmscreen’s new Phantom HALR surface — HALR standing for ‘High Ambient Light Rejection’. Stewart is a great believer in a ‘horses for courses’ approach, and after more than 70 years providing screens to professionals, commercial and domestic customers, it offers a wide range of surfaces suitable to their customers’ equally wide range of applications. It is all about selecting the most appropriate screen surface for the given space.

Stewart’s solution is the use of multiple screen layers, with differing properties. On the very front of a Phantom HALR screen is a two-way diffusion layer through which light passes to reach a second layer. That second layer has a highly reflective optical coating, so that the projector light then bounces back through the front diffusion layer to the viewing position. That’s your movie image sorted, and in full quality; Stewart notes in particular that there is none of the colour shift that occurs on some other ‘ALR’ screens, so that Phantom HALR will calibrate out to Rec. 2020 or Rec. 709 without obvious aberrations that skew the primary and secondary colours.Phantom HALR is the very latest in solving the cinema-age-old issues of ambient light. And this is a clever trick, when you think about it. Projection screens are built to reflect the light from your projector back to your viewing position — but here we’re asking the screen to keep reflecting that projector light while not reflecting the light from anywhere else.

But for ambient light, the dual-layer design is able to reject light coming from angles other than the perpendicular. It’s double protection, indeed, since any ambient light that sneaks through the diffuser layer on the way in can be blocked, post-reflection, on the way back out. The result — clear from the images here — is that a Phantom HALR projection screen can deliver a peak gain of 1.0 while achieving 82% ambient light rejection.

Flexibility AND transparency
Other ambient light rejection screens are available, but Stewart’s Phantom HALR has a number of clear advantages. First is that colour accuracy, delivering a daytime image as richly as you’d hope to enjoy at night.

Secondly, Phantom HALR is the only ALR screen on the market that can be acoustically transparent, perforated using Stewart’s Microperf X² THX-Ultra or Cinemaperf.

This allows you to have the front LCR speakers behind the screen — which not only better locks the sound to the image across a range of viewing positions, it’s a huge potential bonus in domestic neatness.

Phantom HALR is also a flexible fabric, where most examples of ALR surfaces can be used only on rigid and fixed frames. Phantom HALR is available on any of Stewart’s roller-screen models, allowing the screen to be hidden away when not in use — another gift to domestic order.

A further advantage comes from Stewart’s experience in catering to not only the movie industry but also commercial spaces like galleries and museums — they know how to make things big. Most ALR screens are strictly limited in size before multiple sections have to be welded together, with potentially visible joins. Stewart can deliver seamless Phantom HALR screens up to 27 metres by 12 metres! (If you’re still thinking your 65-inch TV can rival projection systems, do the maths — that’s a 1163-inch diagonal, baby.)

Any limitations? Stewart specifies a minimum throw distance of 1.8 times the screen width to avoid hotspotting. And where SnoMatte 100 hardly drops a photon even up to viewing angles of 60 or 70 degrees, as might be required in a large and wide auditorium, Phantom HALR drops more quickly to be 0.5 by the time you are 30 degrees off axis (see graph, right) — a direct quid pro quo for the ambient light rejection.

Conclusion
Phantom HALR is a powerful new arrival to bolster Stewart’s wide-ranging screen selections, and has clear applications in the home where a dedicated and darkened room is not available or desired. As the images show, business boardrooms and other commercial spaces could equally benefit from its high ambient light rejection. Is it right for you? Stewart Filmscreen’s distributor Visual Fidelity and its network of dealers can advise and quote on the options available. Then sit back and enjoy your bigscreen entertainment — night and day.

Stewart Filmscreen Phantom HALR

Contact: Visual Fidelity
Telephone: 03 9338 8995
Web: www.stewartfilmscreen.com