Cinema audiences have become very demanding—so the content and experience offered should make it worth their effort to show up. Laser illumination technology can offer brighter and better images that contribute to a better moviegoer experience, as well as save on operational costs for exhibitors.
Coming from an age where the primary, if not the only, purpose of a cinema was to provide entertainment by showing movies, today digital cinema has become a platform for education, advertising, B2B activities, and extended entertainment and content applications. In all these spheres, it is crucial to match the content and the experience to audience expectations.
The newest technology for immersive imaging is laser light. The major benefits of laser-based projectors are high brightness (enabling brighter 3D images), stable light output, and fewer lamp-related problems (such as flicker and explosions). Another huge advantage, particularly for projection onto very large screens, is the operational savings (eliminating lamp purchase, replacement, disposal, planning, and managing lamp warranties). Many challenges still remain, however, especially with regard to image quality. Laser scores high on gamut, contrast, and uniformity, but also on speckle: twinkling, granular effects that are useful in some scientific applications, but a severe drawback on the movie screen. Moreover, the initial purchase price for laser projectors is still high, because lasers are a new technology and have yet to reach industrial-scale volumes. Regulations regarding eye safety will change soon, thanks to the efforts of the Laser Illuminated Projector Association (LIPA), allowing laser projection to be treated on equal footing with lamp-based projectors.
Exhibitors wanting to switch to laser projectors must choose between two types of high-brightness laser projectors (up to 60,000 lumens). The direct-coupled laser projector (with an integrated light source) is the most efficient solution, with the lowest total cost of ownership for the brightest projector and the best performance in terms of despeckling and image uniformity. The challenges here are twofold: first, the integrated result can only be achieved by installing a new projector, second, you need an external chiller to maximize the lifetime of the laser components and DMDs. The second projector type, the fiber-coupled laser projector (using an external laser light source), sounds better on the surface: it is faster to develop, it can provide flexible light output, and it allows you to retrofit your existing projectors. But if we look deeper, we see that the challenges are significant: the very high cost of fiber, significantly lower efficiency due to fiber losses, greater fragility, and the need for additional external components (including the laser light source and chillers)—all of which add up to a higher total cost of ownership for the fiber-based solution.
And while retrofit seems appealing, the fact is that the big-ticket items today are the lasers themselves and the dedicated cooling. Moreover, retrofitting existing projection systems voids product safety warranties, requiring recertification (possibly in the factory), and the performance of the upgraded projector can never be higher than that of the original. All this means that today, the retrofit path makes no financial sense.
A different laser technology is available in the lower brightness range (5-6,000 DCI lumens): a laser-phosphor hybrid, using a blue laser and yellow phosphor to generate white light. This technology is still limited in brightness, however, and it cannot provide the high brightness levels necessary for premium screens and higher 3D foot-lamberts.
Regardless of the product concept (direct, fiber, or laser-phosphor), it’s very important to extend the lifetime of the system’s most expensive and crucial component: the lasers. Depending on the product concept, lifetime specifications range from 20,000 hours with a 50% drop in brightness (and a 20% drop at 8,000 hours) at one end of the spectrum to 30,000 hours with a 20% drop in brightness at the other. That’s a factor-of-four difference in lifetime comparing the same brightness level, illustrating that it’s important to look not only at the nominal lifetime but also the light source’s estimated brightness decay.
In 2014 we will—finally!—see the first laser projectors come onto the digital cinema market, entering from both the extremely high-brightness and low-brightness ends. Many product attributes have to be taken into account to understand this new technology, such as image quality, system efficiency, TCO, laser lifetime, and so forth. These points can differ dramatically among laser projection models. While laser projection will initially be expensive (like any other new technology), we are convinced that the promise it holds, in terms of both a richer audience experience and operational benefits for exhibitors, will enable its adoption on a wider scale.
Author: Goran Stojmenovik
For more details, see Goran Stojmenovik’s presentation on the MEDIA Salles website.
See also Mr. Stojmenovik’s LinkedIn blog.
The Barco website contains short reference stories about two small cinemas: The Birks (Scotland) and Cinema De Keizer (Belgium). The Barco website contains the white paper “Shaping the Cinema of the Future".