Electronic projectors have come a long way in the last few years so that they now present a viable alternative to a conventional film projector. However, there are still several obstacles that prevent the widespread adoption of digital projectors, with their associated lack of film. Are the potential gains worth the investment? Many of those who manage and operate cinema chains still believe that the present and near future of cinema lies in forcing a bright light through the tiny gate of a 35 mm film projector. Jim Slater looks at some of the issues involved.
Electronic digital cinema is the focus of many papers and demonstrations at exhibitions around the world. The reasons why these things started to happen are complex, but the fundamental one is to do with the available technologies. For the first time, electronic projectors (video projectors in other words), have become capable of providing images with a brightness and resolution that their designers aren’t ashamed of. Previously, video projectors hardly dared to project their feeble flickering line-ridden rasters anywhere remotely within comparison range of even the oldest and least expensive 35 mm film projector, which could and would outgun them for brightness, resolution, contrast and colour fidelity. There was no point in even thinking about electronic cinema at a time when there was no possible replacement for the film projector, so, although the futurewatchers could see potential advantages to removing film from the cinema, nothing much was done except for a few European funded high-definition television research projects.
The cinema business
The fundamentals of the cinema industry have changed little during the century of its existence. The process has been one of continuous improvement and development, rather than revolution, and the addition of sound in the late 1920s, colour in the 1930s, and numerous changes in aspect ratios and widescreen formats in the 1950s (no, we still don’t have a single standard!) brought us to today’s cinemas, which still almost exclusively use 35 mm film. Carbon-arc lamps have generally been replaced with the far safer and more convenient Xenon bulbs (although there are still a few cinemas using carbons, even in 2002). The introduction of digital sound, with its many multi-channel variants providing ‘surround-sound’ effects, made for enormous improvements in the area o sound. One thing that has virtually stayed the same over the last 50 years, though, is the use of the electromechanical projection technology – a 35 mm film projector is a generally reliable and robust device that requires few high-tech skills to keep operational. There have been few technical developments in this area until very recently, when the potential competition from the digital projectors caused the film manufacturers’ research laboratories to look at possible ways of increasing the light efficiency and film handling capabilities of 35 mm projectors. The truth is that the current method of film distribution and exhibition works as a business model, and although there have been some criticisms of it, there has been no reason to change things.
Drivers for change
The drive for change has come from those who are pushing new technologies, and in particular, from those who are bringing radical new electronic projection methods to market. It is worth noting that just because a new technology exists, and has the capability of ousting the original ways of doing things, it doesn’t always eliminate the old – teletext didn’t replace newspapers.
To better understand the potential competition, what is allegedly wrong with the current system? What problem is electronic cinema trying to solve?
Start at the customer’s end with the picture on screen, there is no problem at all with quality when a pristine new 35 mm print is projected through a properly aligned projection and sound reproduction system onto a standard screen. The images are bright, sharp, detailed, well focused and with plenty of contrast, and large enough to impress anyone. Going to the cinema to see well-presented films is still an event, something worth getting out of your armchair for. Kodak suggests that current print films have such fine resolution that it would need television pictures of over 4000 lines to even begin to compete, and even the best video projection systems currently manage much less than this.
So picture quality is fine with a first run print at a premier venue, but what happens down the line? Film damage and degradation is inevitable over a long period, due to the mechanical stresses and strains to which the film is subjected as it is dragged through a projector, stopping and starting thousands of times a minute. However, carefully handled prints should be capable of being played out tens of times without damage. The scratches, dust and other blemishes that we frequently see in ‘ordinary’ cinemas are in some ways due to the mismanagement of the cinema operators. One or two projectionists have to cope with perhaps ten screens simultaneously, with short gaps between showings and a general atmosphere of rushing about that leaves little time for film to be given the tender loving care that it requires. It is also true that projectionist training isn’t always what it used to be; projectionists are possibly never taught to take particular care in handling film, and merely learn by experience that they will not be judged harshly if ther are a few blemishes here and there on the output. Their main goal is to ensure that everything is running smoothly in all the auditoria.
Storage and transport – cans and vans
Storage of film is simple – it consists of little more than adequate shelving for film cans, with air conditioning and fireproof areas in a perfect world. Film transport is by vans, and the film distributors have well established and efficient logistics operations that cope well with ensuring that the right film ends up at the right cinema at the right time.
Multiple prints – the business implications
A typical movie for general release in the UK will have about 350 prints made, the figure in the US being around 2500. The number of prints is very important to those making calculations about the viability of replacing prints by electronic distribution, since with the average print costing between £800 and £1000, a difference of a few hundred prints can make the difference between whether or not it would be worthwhile distributing electronically. The current system of film duplication, distribution and transportation has been in existence for decades, whereas any new replacement system is going to need enormous capital investment at the beginning, and financiers only make such investments when they are convinced that the outcome will be profitable, at least in the medium term. The long-term financial implications of replacing prints by electronic data-streams apply not only to the cinema exhibition part of the industry, but also to the film-processing companies and to those who supply their equipment and chemicals – they could see a drastic fall in the need for their services.
At the beginning of the cinema chain the film camera and film-related production techniques are so well established that even in the face of stiff competition from many different types of video camera, film has so far held its own in many fields, not only for mainstream movies, but also for much television drama. Film is high-quality, flexible, and future-proof, and the images can be used for any purpose, from television programmes to cinema theatre projection. Financially, it is worth noting that film camera equipment is far more long-lasting than its video equivalent. If you bought an Arri camera 25 years ago for a few thousand pounds, it would still be usable today, capable of providing first class results, whereas if you went the video route when it first became available you would have had to replace your equipment many times as formats changed, and there is little hope that new developments in video camera technology will not continue to make last year’s kit obsolete. Film cameras have also improved to meet the competition, with variable speeds and remote control, and have not been ashamed to adopt technologies such as ‘video assist’ when their advantages became plain.
So, having looked all along the cinema exhibition chain, we haven’t yet really found one single good technical or operational reason why the whole system should be replaced – so, ‘if it ain’t broke, why fix it’? Let us see how a replacement all-electronic system might work, and examine the pros and cons of parts of the electronic cinema chain as we move from origination to exhibition.
The alternative scenario Origination
Film cameras will continue to be used, but high quality digital video camcorders can capture excellent high definition images on tape, giving sparkling, noisefree images on large cinema screens. The video camera provides a digital representation of the images directly, whilst the camera film needs to be scanned using a telecine machine to produce the required digital signals. Telecines can scan film at resolutions of 2000 lines, with some specialist machines being capable of double this and provide the high speed datastream to be fed into our future cinema distribution system. The digital data is likely to go into a post-production house to have special effects added, and laser scanners take the digital data and record pristine images back on to film.
An electronic cinema system could reduce the time between a film being finished and its being made ready for physical distribution by several weeks, the time that it takes to arrange for the digital output from the post-production house to be scanned back to film and for a film duplication house to make hundreds or thousands of print copies and distribute them in cans and vans to the cinemas. A movie could be finished one day and available in cinemas around the world the next.
It is interesting to consider what physical medium the programme material might be stored on at the origination end. A typical movie of around two hours would need about 50 Gbytes of storage, even after compression, and cheap storage technology is developing fast enough for the cinema industry, with computer servers containing stacks of hard disk drives being perfectly feasible. ‘Originals’ could be stored on magnetic data tapes or optical discs. The future of digital cinema undoubtedly depends upon the transmission of digital data, and not on the physical transportation of data on some storage medium, but it is interesting to reflect that if anyone were to suggest a cinema chain where the material was to be delivered physically to cinemas, none of the current storage media would have much of an advantage over reels of film in cans.
Data – rates and quantities
A studio quality television image requires around 200 Mbits per second of data, and digital compression techniques allow us to receive watchable versions of this at around 4 Mbit/s on our television receivers. For a high-definition television equivalent image, as envisaged for electronic cinema, the baseline data rate is of the order of 1 Gbit/second. It would be great to store this on hard disk and to transmit this amount of data to every cinema via a wideband link, but economics dictate that somewhere along the line, compression must come in. Demonstrations have shown that excellent quality cinema pictures and sound can be obtained from bit rates of 45 Mbit/s, representing compression ratios from 25 to 40:1.
Film piracy is a concern, with worries about the duplication of a digital master copy of a movie to produce digital ‘clones’, but well established techniques of using digital encryption can protect programme material from copying. Before a digital cinema system is established, agreement will be needed on the encryption and security systems that are to be used.
Central playout and distribution centre
It is possible to imagine a playout and distribution centre which would contain the playout equipment (telecine and video player, perhaps), digital storage facilities, and compression and encryption equipment. The output would probably then be fed via cable to a satellite uplink provider.
Although a network of high bandwidth fibre optic links to cinemas could be envisaged, it would be extremely expensive to get such fibres to all the remote cinemas in rural areas. Satellite distribution is financially more realistic, as a medium-powered satellite transponder can reliably transmit information at around 45 Mbit/s – the whole of the transponder’s bit rate could be given over to a single cinema programme, and the transmission coding system will ensure that any errors are corrected. Today’s satellites can have around 20 different transponders on board, which could make the economics of transmitting multiple films to the multiplexes realistic. Full-time use of a transponder costs around £1.5 million a year, so could only be justified if thousands of cinemas use the resulting output.
Receiving and storing the electronic programmes at the cinema
Signals can be received on small dishes and a standard satellite receiver. It is unlikely that satellite-delivered films will be shown ‘live’ as they are received, although this facility would certainly be possible, with pay per view techniques incorporated. This would allow cinemas to show live sporting events as an extra source of revenue, making better use of their facilities, which are normally used for only a few hours each day. The data will be stored, probably on hard disk in each cinema, ready for playout when required. Error-protection techniques are used on the transmissions, and since the films can be transmitted prior to the actual show times, movies can be previewed beforehand, to check that all is well and arrange for a retransmission if necessary. These processes can be carried out automatically by an electronic theatre management system. The stored data will be decrypted and decoded before being fed to the electronic projector. One of the features that the encryption system can provide is to ensure that films can only be played out at the times and during the dates that have been agreed in the transmission licence; there will in general be no need for films to be stored on hard disk for longer than the period for which permission has been granted, so no need for storage archives at cinemas.
System management – computer control
An electronic system can include a complete management system with a return link between the theatre and the distribution/playout centre. The theatre management system can be linked to the distribution network management system, allowing constant remote monitoring of what is happening at any cinema, including control and reporting of ticketing, concession sales and the environmental state. Software control provides flexibility in areas such as screen scheduling. Since each digital ‘film’ will be just data on a hard disk, the computer can be used to feed any movie to the projector in any one or more of the screens. Management can take advantage of the more flexible operational schedules that an electronic system makes possible, and last minute changes to trailers and advertisements will become the norm – it will be possible to have different combinations for every show in every auditorium, with specialised advertisements to suit each audience; the cinema advertising sales organisations are already investigating the possibilities.
Modifying existing cinemas
For there to be a rapid take-up, the system cannot be used only in new, purpose-built cinemas – digital cinema equipment needs to fit in with existing facilities. It must meet existing technical regulations and requirements for power, air conditioning, space and accessibility, and it must also be capable of working with existing screens, sound systems, and automation systems. The new projection equipment is likely to be internally more complex than the relatively simple electro-mechanical projectors that operators have been used to, so it will need to be reliable and simple to operate by existing staff. The equipment comes with built-in diagnostic software and straightforward test routines, with indicators to show such things as lamp condition and the need for maintenance.
The key item in any digital cinema system, the last link in the chain apart from the screen, is the digital video projector. If it can’t provide pictures as good as those that we are used to from film, then there is little point in adopting a digital system. I will not dwell on the actual projectors, since there is technical information available elsewhere, but suffice it to say that there are three major projection technologies, each capable of delivering what the industry needs. A summary would be that that although none of the available projectors can produce images that exactly match the best that 35 mm film can provide under ideal circumstances, especially in terms of resolution, they can produce spectacularly good large screen pictures which are currently perfectly good enough to satisfy all but the most demanding audiences, and they have the technical promise to get better and better. Bright, sharp, high resolution images are available for every showing, week after week, when a conventional film would be showing unmissable signs of wear and tear.
A brief summary of the technical areas shows that screen brightness can already match the international standards for film, that work still needs to be done on matching the colorimetry of the old and new systems, but the results are currently perfectly acceptable. Available contrast ratios are still lower than when film is shown under perfect conditions, but many films are not shown under such circumstances, and the contrast performance of the new projectors is improving steadily. Resolution is still significantly less than the theoretical best that film can provide, but practical side by side demonstrations have shown that current systems are perfectly acceptable to cinema audiences, and the resolution of digital systems will increase significantly in the near future.
The best of the current digital projectors are perfectly good enough to satisfy the cinema audience, but when making comparisons, note that the digital projectors cost from £70,000 to £120,000 whereas you can buy a pretty good 35 mm projector new for around £20,000.
Electronic cinema – how close are we?
Most parts of the proposed electronic cinema system are now or could very soon become a technical reality, and international standards bodies are working on each part of the chain. Most of the film versus video projection ‘shoot-outs’ have compared the projected video images with those of brand new pristine quality 35 mm prints. The fact that the current video projectors stand up to this type of comparison so well suggests that in everyday use in a ‘run of the mill’ cinema, where the video images should properly be compared with the result from older, much used prints, which will have collected dirt and scratches and the wear that can lead to weave and judder, the video projector would provide much better pictures.
As we move towards the complete electronic cinema chain, there is no doubt that noise-free electronic pictures, distributed via satellite and stored on hard disk in the cinema, could beat those from anything other than a first run pristine 35 mm print. The fact that video projectors don’t have to physically move the film about will also mean that banks of video projectors will be far easier to operate than film projectors in the multiscreen megaplexes.
The non-mechanical video projectors are far easier to remote control, and they could be connected via a cinema management system to equipment that both monitors and controls their inputs and outputs. We could realistically foresee a situation where a single operator in a single control room somewhere in the heart of England could look after thousands of screens from Land’s End to John O’Groats. Doubters should note that the complete five channel TV transmitter network of thousands of transmitters situated on remote hilltops all over the land operates completely unattended, with spare equipment switched in to service automatically whenever a problem occurs. Just a handful of shift workers in a central control room are able to monitor the network to check that all is well, and to ensure that the automatic back-up procedures have worked. How long will it be before some cinema company decides to follow the route that the broadcasters took?
Reasons for change?
It is now technically possible to start the process of moving the cinema industry towards an all electronic future. So what is slowing the process, and what reasons are there to make the change?
A big problem is to overcome the huge difference in capital cost between video projectors and the cost of a good 35 mm cine film projector. The initial costs of setting up the satellite programme distribution system and the computerised management system that needs to go along with it will also be considerable, and there is a significant issue that those who must make the initial investments are not necessarily those who will get the long-term financial benefits. For example, completely reequipping a chain of cinemas with video projectors and satellite reception equipment will cost the exhibitors a great deal of money, whereas they will make only marginal savings in the short term. The distributors, however, who have traditionally worked quite separately from the exhibitors, will save millions by not having to produce and physically distribute tens of thousands of film prints a year, for a modest outlay on more telecine facilities and hiring satellite transmission capacity. Satellite operators will benefit, being able to use their existing infrastructure for a whole new world-wide business, but film processing and duplication companies will lose a major part of their livelihood. Society may benefit as digital cinema eliminates environmental hazards from the disposal of film.
It needs someone to take an overview of the whole chain to determine where investment is needed and how the resulting rewards can be recouped. There is no doubt that a move to a completely digital system will require immense capital spending and a determination to succeed that can only happen if the world’s financial markets can be convinced that the long-term benefits really can make the cinema presentation industry more profitable.
From this simple conclusion a whole new industry is beginning, and it does seem that the investment now being made really could be the start of a move to video distribution and projection by cinema chains. The technology allows digital cinema to address industry needs and concerns regarding quality, reliability, security, and controllability in a cost efficient way. Much is happening, and many companies are involved; it will be quite an adventure, but the huge investments currently being made will make digital cinema a reality, revolutionising the film distribution and exhibition process.
Once the business model can be finally agreed, other real benefits for cinemagoers may well result. Eliminating the costs of duplicating and physically distributing films could make it worthwhile for distributors to offer a much wider range of ‘non-blockbuster’ films to local multiplexes, making it possible for all of us to see the specialist or art-house films that we read about in the press reviews, but which currently never find their way outside the capital city. Already the representatives from France and from Scandinavia on the technical standards committees are highlighting the benefits that electronic cinema could bring to their ‘community cinemas’. It would allow people in remote village halls to watch not only the movies that they would otherwise have to travel to the big cities to see, but also it would provide a marketplace for locally produced cinema material, something that is dear to the hearts of those who feel that Hollywood has exerted its global powers for far too long.
Jim Slater worked in various engineering roles for the BBC, IBA and ITC for some 30 years. Since 1993, he has been a consultant and is currently managing a series of Audio Description trials for the UK digital broadcasters. He also works as an ‘expert’ for the Commission of the European Communities, and acted as rapporteur on the Coordination Board. Jim writes and lectures on a wide range of subjects, specialising in explaining complex subjects in a manner that can easily be understood by the layman. He is Managing Editor of Image Technology and Cinema Technology, the journals of the BKSTS, the Moving Image Society, of which he is a Fellow. He is also a member of various national and international standards groups.