The future of digital cinema

The laser projection for cinema, thinks above all in the spectators, although the majority does not even differentiate between the digital and the celluloid.

By Juan Carlos Chavez *

Once the digital cinema conversion is completed throughout the sector, and with the first digital projectors approaching the end of their useful life, the exhibitors will have to consider - as soon as possible - how and with what to replace their digital projection equipment. The VPF (distributors' aid to digitization) is over, and the multiplication of technological options makes it increasingly complex to decide the way forward. One of these options attracts great attention lately: the laser projection. Until very recently the laser projection was only available to rooms of the highest level.

- Advertising -

It offered an image of high brightness and great color, but for most of the exhibitors their profitability was rather dubious. Well, that is about to change, and in this article we propose to explore the reasons that will soon make RGB laser projection the technology most used to illuminate cinema screens. The time has come for our industry to re-focus on the spectator's experience, on the people who choose to invest the budget they spend on entertainment in watching movies in theaters.

We are in a position to state that the public has not benefited from the initial deployment of digital cinema as much as studios or exhibitors. In fact, most of the viewers did not even differentiate between digital and celluloid. Today, of course, there is the possibility of choosing 3D, but the low brightness of the images and the unequal gain of the screens have created new problems in many important markets of the world. Therefore, if we want the audience to continue to go to theaters we have to offer the best possible experience, and that begins by filling the screen with spectacular images.

A spectacular image on the screen
The answer is quite simple: the brighter the better; The colors will be perceived more precise and natural, the contrast will be greater and the high resolution will reproduce the details more accurately. The large studios that defined the original DCI specifications for digital cinema projectors knew it well. Hence, they will specify precise standards for the brightness on the screen, color gamut, contrast ratio and pixel resolutions required for digital cinema equipment. Specifications that lived up to the high technology of those years, that is, the technology of more than a decade ago.

At that time it was known:
>> How to illuminate the screens to 14 fL (although not in 3D)
>> That xenon lamps reproduced the P3 color range
>> That the image chips could achieve a certain contrast ratio and resolution

So, standards became those.

However, the display industry has advanced at a high rate. Today, consumers can purchase cheap display devices for home use with higher resolution, better color, astonishing contrast and higher HDR (high dynamic range) than most cinemas.

The younger generation is more "plugged" into technology, and will begin to perceive the presence of these new visual aesthetics, or their absence in the event that our industry is unable to progress in parallel to the advancement of technology.

Laser phosphor projection
One of the most interesting innovations recently appeared in the projection market is the so-called Laser Phosphor (LP / LaPh) or BPP (blue laser pumped phosphor). At first glance it seemed like a revolution because it enables the creation of white projection light using exclusively blue lasers, using a mature and economical laser device technology that requires considerably less cooling than other lasers, thereby allowing manufacturers to produce relatively cheap projectors And require much less maintenance than conventional projectors, especially since there are no lamps in them to change.

Obviously, this absence of lamps also means saving on resources dedicated to requesting, transporting, storing, replacing and disposing of harmful materials for the environment. In recent years impressive demonstrations have been carried out and commercial products using this technology have emerged, whose power reaches the 30.000 lumens.

But LaPh technology has some major drawbacks, especially in film. To begin with, the conversion of blue to white light carries a great waste of energy (> 50%). In addition, the native color spectrum of this type of projector is usually smaller than that of the triangle Rec.709 of Figure 1, being especially deficient in the case of green and red, essential colors to obtain a natural-looking image.

Consequently, to achieve a minimally acceptable performance of color that does not impose glare sacrifices, projector engineers with LaPh are forced to make difficult decisions in the design of the yellow notch filter (YNF). In the case of LaPh technology, the YNF will waste up to 50% of available light to meet the demanding DCI P3 specification for cinema.

Let's get back to the audience experience
What should be no doubt is that lasers have the potential to drastically improve the quality of the image of the cinema screens. But to achieve this, the industry is required to evolve towards RGB laser projectors. In these projectors the light comes from a combination of Red, Green and Blue laser light sufficiently precise to cover and to incorporate the range of color Rec.2020.

At the same time, having red and green lasers completely avoids the loss of efficiency per conversion we detected in LaPh projectors. In addition - which is just as important for film applications - to achieve the DCI P3 color specification no loss of brightness is required from a YNF. If more RGB light is needed on an RGB laser projector, simply add more red lasers.

In fact, when converting laser light into a usable light on a cinema screen, an RGB laser system is four to five times more efficient than a LaPh projector. In conclusion, RGB laser projectors have the possibility of reaching levels of brightness much higher than those achieved with LaPh projectors, while offering enormous advantages in terms of the contrast ratio achievable on the screen. RGB lasers are the only film lighting technology capable of delivering HDR (high dynamic range) on the screen.

Which leads us to an obvious question: why bother with the LaPh projectors? The short answer is that, today, red and green laser devices are still considerably more expensive than the blue lasers used in LaPh projectors.

The next generation of RGB laser projection
At the moment, the good news for the film industry is the recent advances in the field of red and green laser technology that will soon change everything. The next generation of laser devices, already in operation in laboratories and prototypes of RGB laser projectors, is much more efficient than the projectors that currently operate in premium cinemas around the world.

In addition, these next-generation lasers do not need to be refrigerated like the current ones, thus allowing a major reduction in complexity, size, reliability and cost of the system. Soon manufacturers will begin to introduce RGB laser projectors for cinema in conventional rooms, which will operate with a cost of ownership equivalent to that of a projector of the same type. These new projectors will put on the screen a better image in terms of brightness, color and contrast ratio, with the added advantage of not needing lamp changes.

If the film industry wants to survive the onslaught of technology and the diversity of choices the consumer finds in other entertainment venues, exhibitors will have to strive to provide their audiences with spectacular screen experiences. The screen image is an important part of those experiences, and lasers can play a key role in improving cinema for all.

However, exhibitors must also understand that LaPh is a transient technology, suitable only for small cinemas where the projectors can operate at low brightness and with the YNF intact. As the next generation of RGB laser projectors comes on the market, manufacturers will increase production for economies of scale. The new projectors will soon dominate the film industry, replacing both lamp and phosphor laser technology and generating real benefits to who really matters: the audience.

* Juan Carlos Chávez is director of Christie in Latin America.

Quoting products and technical services for Latin America

Latest Posts

Latest Reviews

  • We sell equipment sounds consoles, crane, monitor and masss via mail more information ...


  • We sell lighting equipment, monitors, cranes, sound and mass console. ... interested to answer via ...


  • Good Morning. Because the correspondent of Cúcuta most of the time does not say hello?


  • In Colombia a company I quote a team of those for about 60 million pesos ... it's a shame because ...