Introduction to Digital Cinema

by Michael Karagosian
©2003 Karagosian MacCalla Partners, all rights reserved worldwide
Published in the December 2003 issue of INS Asia Magazine

There are few topics in the technical realm that have touched as many disciplines with emotion and politics as digital cinema. The very definition of the words has stirred passionate action. What I will outline in this and subsequent articles is the story behind digital cinema: the beliefs, the motivation, the missing links, and of course, the technology.

As a starting point, I'll suggest a simple definition for cinema: the art of presenting motion pictures. Since this simple definition is not technology-dependent, I can also define digital cinema as the art of presenting motion pictures. Note that I didn't define digital cinema as associated with digitally produced motion pictures. The source technology is not important. The "digital" in digital cinema is about the distribution format and how the image is displayed.

My simple definition is elegant, but unfortunately, it has a problem. There's nothing in this definition that connects cinema to a particular image quality level. Why do we need this? This deserves a quick review.

Historically, cinema has been about the display of film-based content. While other distribution media have been introduced since the advent of film, such as broadcasting, consumer video tape, laser disc, DVD, and MPEG files over the Internet, none produce pictures superior to that of film. This natural division in quality has allowed motion picture exhibition to escape the electronic revolution of the past 50 years. More importantly, it is this division in quality that has made viable the staggered release windows that are unique to the distribution of motion pictures. By release windows, I refer to the timing of when movies are released on the various media available. DVD sales, for instance, generally do not take place until 4 to 6 months following the release of the movie in the theatre.

My simple definition of cinema, therefore, may describe the cinema business of 60 years ago, but it doesn't take into account the staggered release windows in use today. If I define cinema as the art of presenting film-based motion pictures, then I capture the quality difference between that found in the cinema, and that found elsewhere. I can think of no one in Hollywood who would question that definition. But it doesn't translate well when we replace the word 'film' with 'digital'. Aren't we watching digital motion pictures with our DVDs and the Internet? This has been the cause of much discussion in Hollywood, and indeed, most of the world, with the result that the accepted definition of digital cinema is the art of presenting first-run motion pictures.

That's a lot of explanation, but in doing so I hope to make a point: quality is an important aspect of cinema, not just simply for the sake of delivering quality images to an audience, but it's also important to the business model. Note that the definition of digital cinema does not have the word "quality" in it. But it is because of the concern for quality that the definition has taken the form that it has.

With our well-founded definition as a starting point, let's explore other issues behind digital cinema.

Our definition of digital cinema allows us to split the universe of theatrical presentation into digital cinema and everything else. Not wanting to coin a new term, the more common language applied to 'everything else' is alternative entertainment, or other digital stuff (ODS). The point being that theatrical presentation can be divided into two classes, one having the highest quality possible, the other less restrictive in quality. This is perhaps one of the pillars of current thinking in electronic exhibition.

There are some 150 trial digital cinema systems in the world today. These include installations in China, Singapore, and Thailand. Definitions being important, the term 'trial digital cinema system' is carefully chosen. Contrary to the promotion and press one may read, these are not systems ready for a world-wide rollout of digital cinema. These systems are in place for studios and exhibitors to gain hands-on experience with digital presentation. The honest fact is that, in the eyes of both Hollywood and exhibitors, there isn't a system today that is suitable for a wide-spread rollout of digital cinema. But that's a very different problem which this article will only begin to address.

Altogether, it's important to note that digital cinema has many forces pushing it forward, and many forces that inhibit it from moving forward. Both sets of forces need to be understood to fully grasp the complexity of introducing this technology to the cinema. These forces are comprised of many issues, which include benefits to distribution, benefits to the audience, system cost, financial contribution by the studios in purchasing systems, image quality, security, interoperability, differentiation from the home, electronic management of business, and of course, the details of the technology itself. I will address many of these issues in later articles.

To gain perspective, it's useful to understand how we arrived at where we are today. The concept of electronic cinema is actually quite old now - dating back before the mid-20th century. Electronic cinema was discussed before the introduction of television. It began to take a tangible shape in the early 90's, when the Hughes/JVC ILA (Image Light Amplifier) projector became available. This was the first electronic projector that could light up a large cinema screen and produce a picture that was worthy of consideration. The ILA projector, however, suffered from maintenance and alignment issues, making it nearly impossible to use in the 14x7 environment of the cinema, which only magnified its quality problems.

The DLP (Digital Light Processing) projector for cinema, having extended contrast from that of industrial models available at the time, was first demonstrated publicly in 1999. That step in itself was the result of many years of evolutionary work undertaken by Texas Instruments based on feedback from several Hollywood studios. The DLP Cinema projector, as it became known as, has a wider color space from that of television, and a pixel array of 1280 x 1024. DLP technology is based on MEM technology (Micro-Electro-Mechanical), utilizing approximately 1 million mirrors that can flip between reflecting light to the projection lens or reflecting light away from the projection lens. By adding a layer of black material to the area surrounding the mirrors, a contrast ratio of approximately 1000:1 was achieved. Most importantly, the technology has proven to be consistent, stable, and reliable in the theatre environment, posing no maintenance problems. While DLP technology could face interesting competition in the years ahead, without it today, it wouldn't be possible to have a significant discussion of digital cinema. And true to the advancement of technology, a 2nd generation DLP Cinema projection technology was introduced in early 2003, producing even better contrast ratios and having twice the number of pixels in a 2048 x 1024 array.

The challenges faced by digital cinema today can be compared to the layers of an onion. While there are good reasons one could want more from a projection technology, the projection layer has been largely addressed, at least for now, and the other layers of the onion are now exposed. Many technology companies, standards bodies, and industry groups have been working on these layers, and exposing more issues as they go along. Digital cinema remains in a state of evolution. But that evolution could be nearing an end soon. I'll address more layers of the onion in the next issue of INS Asia.