January 3, 2013

The Problem with Silver Screens - Comment by Haris Zambarloukos BSC

Pictured is the Lumière in Regent Street 1896, the first cinema in Britain.

They say it will be the premier viewing experience in the UK. But at this stage they plan to install a silver screen.   Even if they choose a high bred silver screen in won’t be good enough, read on to discover why!

The final task of the Cinematographer on a feature film is to supervise and guide the process of making the theatre release prints, the digital or film reels that get sent to the cinemas. It's a lengthy and precise process, it is when you get to colour grade to the final degree every shot of the film, frame by frame, 24 frames a second. When the prints are struck the film is finally complete and ready for presentation, it's now time for a motion picture's projection.

The art of projecting a film is equal to the art required in any aspect of producing a film, it is, for example, equal to the imagination and craft it takes to create a beautiful gown for the leading lady or the craft it takes to create a compelling close up of the protagonist at a crucial dramatic moment. Film projection is the final display of all the effort and imagination poured into a motion picture by every member of the crew. The responsibility of presenting a feature film to the public is largely in the hands of the exhibitors, or in simple terms, the cinema theatre, the place you hand your money over to in exchange for a few hours of cinematic excitement.

Have you walked out of a theatre in recent years and thought: that film just looked dull, dark, muddy? Where is the richness of colour? The sparkle of light off the screen... Have you noticed how much darker films look when sitting in seats far from the centre of the screen. One simple reason is the screen is silver. It used to be silver in the days of black and white films but from the 1950s until recently the screens became white. So let's take a step back in time and see how this came about and what it means to audiences and their appreciation of a film in a theatre.

The quality of cinema projection is based upon a number of factors. The amount of ambient light, luminous power of the projection, size of the image being projected and reflectance from the screen all have an impact on image quality and the brightness of the image.

During the 1940’s most films were projected in black and white onto a flat silver screen. Low powered carbon arc lamps were used in projectors and to create a brighter and sharper image the highly reflective surface of a silver screen was used. These silver screens were commonly made from a tightly woven silk coated with silver or a silver-like material e.g. a thin layer of aluminium imbedded within the silk. However, these silver screens had a narrow viewing angle due to their poor ability to disperse light. There were also issues such as hotspotting, where the light projected onto the screen would be brightest in the centre, leaving the peripheral darker rather than the whole screen being evenly lit.

With the rise of colour film and continuing innovation in projection and screen technologies, silver screens began to be replaced from the 1950’s with white or grey (to avoid discolouration of the image) vinyl panels and projectors with a stronger source of light. These screens were also designed to improve sound quality and the vinyl panels are covered with millions of small holes to allow sound to pass through from the speakers mounted behind.

Over the last decade with the re-emergence of 3D films in mainstream cinemas there has been a huge increase in the number of silver screens. 3-D projection depends upon maintaining the polarisation of the images presented to each eye (hence the need for polarised glasses). The amount of light reflected from a non-metallic surface varies strongly with the direction of polarisation and the angle of incidence while this is not the case with metal. Polarised 3-D projection requires the use of interposed filters dimming the brightness of the screen therefore silver screens have been re introduced to reflect more light and maintain polarisation.

Now the problem is 3-D films make up just a small portion of films presented in cinemas and that audiences primarily watch 2-D films. The replacement of white vinyl screens with silver screens creates a degradation of 2-D images. The acceptable amount of drop-off in brightness from center to edge is 20%; however, the drop off on silver screens is more and can be unacceptable as it creates a halo effect that alters the colors on the borders of the frame. Blacks also look muddy, whites appear a flat gray and colors look washed out. Interchangeable silver and white screens, or 3-D technology that doesn’t rely on polarization and can be shown on white, is being recommended. It is worth noting that early in 2012 the French film board announced plans to phase out all silver screens for 2-D presentations over the next five years.

There also other factors, like maintaining the projectors and projector bulbs, projectionists were once highly respected craftsmen who knew how to present a film in a particular theatre, in the modern world of automated digital projectors they have been phased out and there is no one in the projection booth checking the quality of each and every presentation. It's a presentation that you paid good money for and that we the crew worked very hard to show you in the best possible way. So don't let a cinema ruin your film, if you don't like the projection of a film complain to the cinema management, chances are they will worry about ticket sales and fix it.

Haris Zambarloukos BSC