With acknowledgement to Ken McFall, Technical Manager at Stratford Picture House. 

Ken was kind enough to allow me to take pictures and answer my questions - thus providing an interesting and informative insight into the technical side of film presentation, and the running of a multi-screen cinema.

What is the cost of the average 35mm print?

This depends on the length of the feature itself, but is I believe in the region of £1200.  

What happens to the prints when they are returned to the distributor?

At one time film releases were timed to open at different dates across the country often accompanied by heavy local television promotion. The prints would then travel around from region to region. However, it did mean that film could not have extended plays at individual cinemas, as the print would already be committed to another cinema. With very large auditoriums this was practical, as a film would run to high capacities for a shorter time. The distribution pattern has changed somewhat in recent years, with smaller auditoria being normal, and films often open as a blanket release across the country. To make this financially viable the films open here well after their American open so that the prints can be cleaned, hopefully, and used here. This is not a firm rule but is happening more and more. Prints tend to have extended runs in multi screen cinemas so after they have finished there may not be a demand for the print. They would be used in another region, stored or destroyed. I'm not sure if there is any recycling possible!

How often is the projector cleaned and how?

Film projection is a mechanical process and this causes the prints to shed dust during the rather violent stresses they endure during projection. Additionally, with long run projection systems being the norm, up to 4 hours of film can be run continuously. It is therefore very important that the film path is cleaned after EVERY run. First thing each morning the whole projector is given a though brush and dusting, particular attention being given to the film gate and sprockets. Thereafter the film path is given a quick dusting during the day after each show.

Is the Picture House equipped to show other film gauges like 16 & 70mm?

16mm film can be shown on an as needed basis. We no longer have our own projector as it was under-utilised at Stratford. However, if needed we can bring in the equipment as required. As far as 70mm is concerned, it is both a question of the cost of completing our existing 70mm projection equipment and the availability of prints. We are already equipped with dual gauge 35/70mm projection equipment in our THX Screen One. We also have a 35/70mm non-rewind. The only thing missing is a suitable sound processor to cope with the magnetic sound format and Digital format used on 70mm prints. The cost of this is unjustified at this time due to the lack of 70mm prints. 70mm prints cost many times more than 35mm prints and can only really be considered viable in the largest of premier cinemas, such as Leicester Square.

What is the procedure when a print becomes damaged?

This depends on how and to what extent the print has been damaged. The main concern is always to get the show back on screen as soon as possible and to minimise the repair / removal of any damaged section. Minor damage, a couple of frames, are removed and considered to be wear and tear and would not require any further action. More extensive damage would be reported to the distributor and a replacement part/print would be obtained. Fortunately, this is a very rare occurrence.

What are the features of the THX sound over Dolby, & do Lucasfilm place any conditions on the use of THX?

The first thing to make clear is that THX is NOT a sound format, whilst Dolby in its various formats is. Dolby SR & Digital are methods of recording the audio in a way that can be reproduced reliably and consistently at the cinema. Dolby has spent many years defining their standards and improving the whole movie going experience. However they cannot do anything about the environment that the film is shown in. This is where Lucasfilm's THX comes into play. THX define minimum standards for the auditorium ambient lighting, ventilation system noise, picture quality (keystone distortion and focus) and most importantly the sound system. Everything must meet or exceed the required standard before a cinema can be licensed to display the THX logo. Once the standard has been achieved the cinema is checked once each year to ensure the standard is maintained. So whilst the public generally associate THX with sound it is in fact the whole environment that it refers to. Ensuring the cinema going public see and hear the film as the director intended.

Is the sound mix and volume adjusted for each print?

Thanks to the efforts of the likes of Dolby laboratories film sound levels do not vary that much. However what does vary is the effect or impact that directors want to put over in the film. Very often if we get a complaint about sound levels it's because the director has decided to recreate the real life sound experience. Often in these cases the main characters speech levels are fine but the other sounds are very loud. A scene in a noisy nightclub would be a good example. We have no way of adjusting the sound levels apart from turning EVERYTHING up or down. We have to set the levels for the main speech, as that is how the director intended his film to sound. For us to make any other adjustments, if it were possible, would be for us to make an artistic change that would not, to my mind, be desirable.

How many sound tracks does a 35mm print carry?

All 35mm prints carry at least an optical sound track. This is currently Dolby SR, giving full stereo sound. The majority of prints also have Dolby Digital giving full 6-channel sound. Prints can also have a time code printed on then to allow the sound to be reproduced from CD. So the average print can have up to four different sound tracks (formats) on them. The most popular being Dolby SR and Dolby Digital (SRD).

Is the theatre lighting controlled independently of the projector?

Yes, it is controlled independently, but it is also controlled by the automation system that runs the performance.

How many different types of lens can the projector be fitted with?

Generally most cinemas only fit two. 1.85, which is the ratio you would normally see the adverts and trailers in and 'Scope' which is the anamorphic system. However, so called Art Houses are generally fitted with up to 5 different ratios. 1.33 being almost square, 1.66, 1.75, 1.85 and Scope being the widest. This is the order that ratios were developed as the film industry matured.

How many commercial film formats are there in use?

Only two are really used today. These being Scope and 1.85.

What is the most common problem encountered in the projection room?

Prints arriving late and the pressure of making up ready for projection.

What material is the screen made of?

Its a plastic type of material which is perforated to allow the sound to pass through it, the speakers being placed directly behind the screen to help reinforce the illusion that the voices of the characters are coming from their mouths. The screen itself can be treated in different ways to improve its light reflection, giving a brighter picture, and for 3D projection. 

Does the projector need to be re-focused after each gate clean?

No. The film gate is fixed and does not move, except when removed for cleaning. The film is pressed lightly against it's surface and the lens is therefore adjusted to focus the film whilst in this position.

Is it easy to thread the print incorrectly?

Certainly, and severe damaged can be caused as a result.

Films don't seem to pick up scratches like before. Why is that?

In the 'Good old days' of 20-minute reels with change over's, each feature would require maybe five or six lacings, each introducing a possibility of error. Each reel would be rewound by hand which again introduced the possibility of scratching and dirt getting onto the print. However, if a reel was incorrectly laced up it was only THAT particular reel that would be damaged. Today with long run equipment it tends to be all or nothing. The whole print would be damaged if regular checks are not made during projection. The introduction of Polyester release prints has also contributed to a reduction in print wear. Polyester prints are extremely strong and can in fact damage the projection equipment if the film becomes jammed during projection. These prints have different characteristics to other types of film stock and are affected by humidity. If the air is too dry the prints become charged with static and can stick to itself during projection. This can cause 'Brain Wrap' as it is called in America. We call it a wrap around. The film wraps around the feed unit on the non- rewind and locks tightly. This causes it to pull at the projector and if you are lucky it will snap. However, what can happen is that the feed unit can be pulled out and damaged, the guide rollers can be pulled out of alignment and the projector can also be damaged. I have even seen a projector pulled over by this. All of these can happen in the space of two or three seconds before the projectors alarm system can kick in. At the Picture House I have adapted and modified a system that will stop our projectors BEFORE it pulls tight at the projector. This means that no damaged is caused to the print at all.

How is the automated screen masking ratio change over operated?

It is simply a matter of changing the position of a metal aperture plate and rotating the lens so that the required lens is in place. The screen masking (the black cloth all around the screen) is changed by a motorised winch system.

Do projector bulbs and fans fail regularly?

Xenon lamps, the lamps that give the light for projection, have a finite life. After that the risk of failure increases rapidly, with explosion being a very real risk!! Therefore lamps are changed no later that 25% over their maximum life. This is in line with the manufacturers recommendations. It is a folly to risk running lamps way over their life as if they do explode they will destroy the glass mirror at the same time. The mirrors in our screen 1 cost £1500.00 each!! Lamps are inspected regularly for discoloration and changes are planned. They are never changed during the day between performances unless a lamp has failed unexpectedly. The lamps have to be cooled constantly as they will explode if they overheat. The cooling system is interlocked with the control circuit so that if the airflow drops below a certain level the lamp is turned off. Intelligent use and planning virtually eliminate problems.

Is security tight given the value of a print and possibility of video piracy?

All prints carry an anti piracy code on them. These codes are in different places on each print and are invisible to the average cinemagoer. The code identifies the print number. All print movements are very tightly controlled and carried out by security carriers. So if a print is 'Borrowed' and pirated the prints can quite easily be identified. This is in addition to the normal building security we are required to have.

How long before all screens go digital and film becomes obsolete?

With current technology it will be a very long time, measured in years. The equipment is VERY expensive and does not offer anywhere near the potential quality of film. This will certainly change in time but it will remain very expensive. There is little attraction for the cinema exhibitor to change over to digital, as there is no benefit for them or the cinemagoer? At the moment the only people who will benefit are the film distributors because they will not have the cost of making prints and moving them around. The cinemagoer will 'See' no real benefit in the short term. In the long term this will change but it is going to take some very difficult decisions by the whole industry before it ever becomes a financial reality. The initial adopters will be the large circuits. However, because of the very high investment required they would need high grossing film to get a return. This means that niche films will become more marginalized, as they do not offer the quick return required. The smaller independent exhibitor will not be in a position to go digital and will be left to run the film that the large circuits won't touch. It will become a very divided exhibition system as a result. The only way out would be for a lease system jointly financed by the distributors to enable digital to be affordable to everyone. When that happens you will see more and more diversification of cinemas, as they will be able to show a wide variety of films with great flexibility, especially obscure films, as only one Digital print would be required. 'Live' televised events will be affordable, as the equipment would already be installed. Large multi-site conferences would also become practical. All of these things are some time off but when they do happen, provided it is affordable, the future of the small to medium sized town cinema is promising.

Can you tell me the origin, age and model of each projector?

We have four Victoria 8 projectors. These are Italian and about 40+ years old. The projectors in screen 1 & 3 are from the Classic Haymarket in London (Now UGC). The projectors in screens 2 & 4 are from the now closed Granada Cinema, Harrow. We have Dolby SR in all screens with Dolby Digital in screens 1 & 3. Digital will be going into screen 2 shortly.

What about current developments in sound technology?

The film industry has been very environmentally aware for many years. They have wanted to remove silver from the film process altogether. However, because of the way optical sound is reproduced this was very difficult. Currently a filament lamp shines a very bright slit of light onto the soundtrack area. As the silvered dark area of the sound track passes in front of the slit of light it stops the light passing through. This causes the light to flicker, which is picked up by a cell, which passes the 'signal' to the sound processor to create the sound you hear in the auditorium. The silver is needed because of its density. The dyes used to create the picture on the film are not dense enough. By using a red Light Emitting Diode (LED) to replace the filament lamp and doing away with the silver and replacing it with a cyan coloured soundtrack the result is the same as before. The cyan colour acts as a very dense barrier to the red light from the LED's so the ratio of light and darkness falling on the cell is the same as with silver soundtracks. Its environmentally friendly and cheaper as well. The only drawback is that the cinema has to payout for the conversion of its equipment.

How do you cope with the Big Block-Buster openings when you have smaller auditoriums?

As explained earlier, when cinemas were single screen with over 2000 seats films would open in different areas and play for limited runs. The introduction of smaller multi screen cinemas means that films cannot realise their potential in short limited runs. It is therefore necessary at times to run a single film print in more than one screen to cope with the initial opening rush. This is called 'Interlocking' and means that a film would start in screen one, run through that projector and then run along rollers down to the next screen and run through that projector. There is obviously a delay between each successive screen, in our case about 90 seconds. The projectors are electronically locked together so that they can be started and stopped simultaneously. They must also run at exactly the same speed without variation. We can run a print in three screens if required. It's quite a sight to see as the film moves along the rollers from one projector to another starting the show as it goes along.

Stratford Picture House Images