Projection screens
Published: WORSHIP
Projection screens - Until recently, few churches were able to use projected images to bring depth to their services. Today, video projection is a prominent worship tool and requires an appropriate screen…
Relatively speaking, it wasn’t so very long ago that a simple overhead projector and a tripod screen were a rare luxury for any but the best facilitated houses of worship. Latterly, however, as churches have grown in size and striven to be culturally and technologically relevant, video has become an essential part of services in houses of worship around the world.
This may be used for IMAG (image magnification) for praise and worship, for when the message is being delivered, or for displaying the words to worship songs as the modern equivalent to the hymnal. It could also be for providing supporting information for the sermon, such as bible verses, or possibly bringing a pastor who is across town, across the country, or even around the world to a neighbourhood in a satellite church. Nowadays, projection systems are commonplace. And what used to be a simple choice of available projection screens has grown to a complex assortment of options.
Is the aspect ratio standard (4:3) or HD (16:9)? Or is some custom size needed because multiple projectors are being edge blended? What is the viewing angle and the screen gain? There is a multitude of screen surfaces available, meeting a broad spread of functions and choices – so which one do you need? While the answers to these questions are probably best left to your system designer or integrator, we will provide some insight to the quandary of choosing a projection screen. Many of the screen manufacturers websites offer extensive resources as well to assist with screen selection.
‘What is the basic aim of having a projection screen in the church?’ says Anjum Parwaiz, area sales manager for dnp denmark – a key question in the design of a suitable projection system. ‘What must it facilitate or help accomplish? Is the idea to just generate a large image to better see the pastor, or is the basic aim more than this?’
The environment itself plays a large part in determining the type and size of projection screen that should be used. The seating area, layout of the church and the proposed placement of the screen also influence the size of the screen. Jim Hoodlebrink, rental products manager for Draper, suggests considering where the projector will be mounted relative to the screen. As far as determining what aspect ratio to use, Mr Hoodlebrink says: ‘Consider whether you should match the native resolution of the projector or match the primary purpose of the room.’ As far as determining the size of the screen (or screens), the considered advice on this is variations on a theme. Serhiy Horokhovskyy from Mocomtech points out that: ‘It’s not always the case that bigger is better and smaller is less effective. In order to determine the best screen size, you need to consider the size of the room because the size of the screen should be proportionate to the room’s size. For the ideal seating arrangement, a person should be able to see the whole width of the screen at approximately 120° (60/60°) from the middle seat on the first row, and at 90° from the middle seat on the last row.’
While many variables are used to determine screen size there is a rule of thumb calculation for data projection to get you in the ballpark: 1/6 the distance from the proposed screen location to that last row of seats. For instance, if the distance from the propose screen location is 60 feet (20m), then the screen height should be 1/6 of that, which would be 10 feet (3m). The width would be determined by what aspect ratio you will project. The most common aspect ratio is 4:3 which would result in a screen width of 13 feet, 4 inches or approximately 4m. A wide-screen format of 16:9 would result in a screen width of 18 feet, 9 inches (approximately 6m). But as Mr Parwaiz says: ‘Common sense and judgement must be applied to either make the screen bigger or smaller depending on the actual design of the church. That is the job of A/V experts to provide guidance and help in each individual case.’
The A/V professional can also help select the optimal screen material for your church. Again environment plays a large part in determining what will work best. While there are quite a few choices of available surfaces, Mr Hoodlebrink suggests: ‘For front projection, matte white is the most common surface because you may have different lighting conditions used in the church. A grey material can help with contrast but you may give up brightness if the projector is not bright enough.’
Matte white screens offer relatively low gain as compared to a glass bead screen or other materials such as aluminium – the material used in screens from Mocomtech As with most things, however, there are usually trade-offs. Says Mr Horokhovskyy: ‘Generally, matte white screens have a wide viewing angle with low brightness, and high-gain screens have high brightness and a narrow viewing angle. You need to consider the pros and cons of different types of screens. Especially in churches, viewing distance should be one of the most important factors to consider (the data and numbers about minimum and maximum viewing distance are usually given by the manufacturers).’
‘Use enough screens to keep most people’s view within 30° of the screen,’ Mr Hoodlebrink suggests. ‘Many times this is not possible depending on the layout, so try to minimise the seats that will have an extreme viewing angle.’
Screen manufacturer dnp offers an optical surface or dark surface projection screen that differs in technology and construction from a traditional screen. This surface material is designed for application in both bright and dark room environments. The technology provides for projector light being focused and intensified before being reflected back to the audience, while ambient light is absorbed. The surface in this case is called an active surface.
Mocomtech manufactures a non-traditional screen as well that provides purportedly high gain with a wide viewing angle, and brightness uniformity across the screen due to a concave curvature of the screen and the aluminium with silicon coating surface material.
As HD grows in popularity should aspects other than screen size be considered? This could be particularly important if using an existing projection surface and just the projector is to be upgraded. According to Mr Hoodlebrink: ‘Most screen materials can handle the resolution, but the image can be more difficult to see with wide viewing angles, or if the image is not bright enough or loses contrast.’
There are many options available and each house of worship will have its own unique requirements for a projection screen. ‘The brightness of the screen is one of the most important factors,’ Mr Horokhovskyy underlines. ‘Many worship facilities have a number of sources of ambient light, which can be the biggest challenge for projection screens. Try it out. Before you install it, compare the screens so you can see the differences under same conditions (same size, lighting condition, and same projected image).’
And Mr Hoodlebrink adds: ‘Consider its use – is it primarily for following a power point, displaying hymn lyrics or for showing video? Font size has to be considered to reach those viewers seated the furthest distance from the screen. If video is the primary then you have to place more importance on those distant seats, as opposed to the optimum seat locations.’
Published in Worship AVL Asia Winter 2010