October 11th, 2023

Understanding the interaction between screens and projection technologies

Over the past twenty years, the requirement for cinema screens has changed dramatically. Prior to digitisation, projection technology had remained relatively stable for decades with significant technical intelligence embedded in to projectionists around the world. That certainty allowed most cinemas to utilise uncoated Matte screens with unity gain to present movies to audiences. The majority of those screens were manufactured at the Gate Studios in Elstree (just north of London), the former global manufacturing site of Harkness and distributed around the world in manageable sized packages. Those screens were distinguished by invisible seams and a fire certificate guaranteeing safety. Whilst Harkness introduced the concept of gain screens in the mid-1980’s through the Perlux product-line the requirement for these was limited and these were often reserved for large format screens.

“Much as today, equipment shortages and a lack of technical certainties (such as light degradation and speckle) require exhibitors converting from xenon to laser to focus on solutions, the transition from film to digital projection also created significant challenges further complicated by the requirement to showcase 3D content,” explains Richard Mitchell, VP at Harkness Screens. “Projection availability and long-term performance unknowns meant that for many exhibitors transitioning to digital through VPF schemes, gain screens were a serious consideration or even necessity for managing and maintaining brightness levels to new industry standards, especially 2D screens,” he adds.

Of course, gain screens such as Harkness’ Perlux range along with Spectral 240 (the silver screen that dominated the global 3D roll-out) required a different approach almost overnight in terms of packaging, shipping and installation but they also required exhibitors to have a different understanding of screen characteristics and performance. Digitisation required screen manufacturers to provide significantly more data regarding their products such as laboratory measured gain curves (which often differ from in-field measurements) to showcase reflectivity but also light distribution of screens and extinction ratio specifically for polarised screens; one of the biggest contributors to the quality of polarised 3D presentation. As the world’s leading manufacturer of cinema screen technology, Harkness utilised a range of technology to support learning starting with an online technical capabilities tool – the Digital Screen Selector which was quickly replaced by a family of calculation and simulation tools such as the 3D Digital Screen Modeller that enabled exhibitors to make informed decisions about their screen choices and screen design in a digital simulated environment.

The learnings of digitisation and the requirements of exhibitors for further improvements to presentation quality allowed Harkness to look at next generation 2D and 3D screen technologies alongside partners. In 2013, RealD, the world’s leading 3D provider launched their own screen technology “Precision White”, a screen produced in partnership with Harkness and RealD continued their search for presentation quality improvements with the launch of the “Ultimate screen” in 2016.

“At the same time that RealD were launching Precision White, Harkness completed a generational technology breakthrough in 3D gain screens creating Clarus XC, an affordable 3D solution with a visibly whiter look and ultra-wide viewing angles meaning the screens had the ability to showcase 2D and 3D presentation equally well,” explains Mark Ashcroft, CEO at Harkness Screens. “Through a range of gain levels, Clarus quickly became the de facto 3D-enabled screen technology with its performance and characteristics acknowledged by the entire cinema industry from film-makers to exhibitors culminating in its use at movie premieres and major trade conventions including Cine Europe and CinemaCon – a trend which continues even today,” he continues.

Clarus technology had not only been designed to improve presentation quality but to act as a compatible screen solution enabling exhibitors to consider the eventual move from xenon-based projectors to laser light sources at the end of VPF. The proprietary optical coating technologies served to reduce the visibility of on-screen speckle whilst improving total integrated scatter (TIS) – a measurement of total light reflectance across the entire screen. The unique attributes which made Clarus XC such a success showcased the ability to make substantial improvements in 2D gain screens and Harkness identified further improvements in optical performance through new coating technologies which enabled the launch of Perlux HiWhite in 2018.

Laser projection has seen further development work at Harkness and the first screen to be delivered with 3rd generation optical coatings is Nova; primarily a 3D screen with a gain profile that can be provided between 2.9 and 3.4 depending on exhibitor requirements.

“Complementing these new screen technologies is a continued commitment from Harkness to providing exhibitors with the necessary information required to understand the implications of screen choice and design on laser projection technologies. This is best showcased through the myHarkness platform launched in 2022 which created a collaborative cloud-based environment for exhibitors to realise the maximum return on investment from screen technology whilst ensuring presentation excellence for movie goers,” Richard adds.

In 2023 this has been taken a step further as Harkness has added further value to rich product data information through the use of video explainers that help exhibitors and specifiers to understand product characteristics in a more compelling way. Easily accessible through the Harkness web site or through a QR code, these videos enable users to understand how the world’s favourite screens work and why they are so important to help optimise operating costs and presentation.

Looking to the future, Mark explains that “in 2024 new screens with next generation optical coatings capable of further reducing the visibility of speckle will be tested and launched. These stunning new screen technologies will enable the cinema industry to present movies as the film maker intended whilst still retaining core components required by exhibitors such as fire safety, durability, lowest carbon footprint and at an operational level management of projection power requirements.”