Making Front Projection Shine in High Ambient Light
By: Jenny Brust and Joe Baer
In an era where new visual technologies are seemingly around every corner, it's no surprise that houses of worship are increasingly using such tools to enhance the quality of their services. While the trend is more pronounced in large churches, just over half of congregations with weekly average attendance of 100 or fewer have indicated they used some form of projection technology on a regular basis.
Projection can be a visually stunning choice for presenting text, still images, movie segments, or video clips. It is also considerably more cost-effective and easier to install than other visual media alternatives – such as plasma, LCD or LED – in sizes at or above a 100-inch diagonal screen. But, the typical house of worship was not designed to optimize display images. The house lights and ambient light flowing through skylights, large stained glass windows, or window walls can spell trouble for projection technology unless church leaders take a thoughtful approach to their multimedia needs.
For houses of worship that are ready to install large screen projection – or upgrade an existing system – the following six-step assessment process can help ensure high-quality results where ambient lighting is an issue.
1. Management of outside light sources
Large decorative windows, skylights, and stained glass give a sanctuary a distinct look and feel. These design elements also add ambiance to the worship experience. For those reasons, church leaders must decide if targeted light management – such as shades or tinted window films – would detract from the worship experience. In many cases, the aesthetic and symbolic value of outside light overrules technological considerations.
2. Management of indoor light sources
Many churches have a combination of lighting sources, which often involve fluorescent or incandescent lighting for general illumination and theatrical or stage lights for the altar and pulpit areas. If that lighting cannot be controlled when projection is in use, the images on most traditional screens will tend to "wash out," greatly reducing the effectiveness of the media experience. When lighting cannot be managed or is desired for the ambiance, church leaders should ask a professional AV systems integrator about new and innovative high-contrast screen technologies that can more effectively capture projected light and deliver spectacular images in high ambient lighting environments that create a better viewing experience for the audience.
3. Sanctuary size and configuration
Once concerns on the outdoor and indoor ambient light issues have been considered, it's time to address how the sanctuary's size and layout affects screen size and placement. For instance, many newer houses of worship with more than 1,000 members feature facilities designed in a semi-circular fashion. In this case, even an extremely large single screen would pose significant problems, such as image cutoffs for worshippers on the far left or right sides of the sanctuary. A better choice is to consider installing at least two smaller screens that frame both sides of the pulpit, or screens comfortably angled on the left and right sides of the altar. For more traditional, rectangle-shaped churches with a large sanctuary, two screens flanking the pulpit may be a sound approach. Smaller churches with a rectangular layout may be able to accomplish their multimedia goals with a single screen.
4. Type of images projected
Different worship leaders have different uses for projection technology. For example, in a large sanctuary, it may be important to have image magnification of the pastor during the service for the benefit of worshippers in the back or to the sides. In houses of worship where technology is a more integrated part of the overall experience, many church leaders have opted for multiple screens – one with magnified images of the worship leaders during service and others handling concurrent text, video, or multimedia images.
5. Screen selection and sizing
While traditional flat screens are economical, they perform poorly in locations where there is high ambient light and rear projection systems have physical space requirements. However, new front projection screen technologies have emerged that can reproduce crystal-clear images – even under challenging ambient lighting conditions.
In terms of sizing, a handy guide for most houses of worship is the "rule of eight." For example, if the most distant viewing area in the sanctuary is 80 feet from the desired screen location, the screen should be no more than 10 feet high. Conversely, there is an ideal 1:1 ratio to measure the distance between the projection screen and the nearest seating. That means if the closest worshippers are 15 feet away, the screen should be no more than 15 feet wide.
6. Projector selection and image brightness
A common dilemma that church leaders often face when discussing front projection image quality is "wants vs. needs." Even in sanctuaries with lots of ambient light, a projector that generates overly bright (as measured in ANSI lumens), but low contrast images will create unnecessary eye fatigue for worshippers. On the other hand, buying a projector that doesn't have enough optical firepower will be a wasted investment.
When evaluating projection needs, a professional integrator will typically take a series of lux (light measured in foot candles) readings. This will measure light reflected off the screen under normal worship service conditions, as well as reflected light in selected viewing locations in the sanctuary. This will help determine how much ambient light the projector needs to overcome. As a next step, the integrator will calculate the screen size and gain to help determine how much lumen output is needed to deliver appropriate image clarity. Since new screen technology can so effectively capture light from a projected source and reproduce uniform images while rejecting ambient light, projector costs can be dramatically reduced. High-powered projectors are simply not required with the proper high-contrast screen. Now church leaders can capture their audience with stunning large displays while keeping the house lights up.
Optical screen gain is critical in projector selection. For example, assume a 12x9 foot screen with a gain of 1 needs a 10,000-lumen projector to achieve the proper brightness. On the other hand, a digital front projection display that produces high image contrast and no decline in off-center brightness can deliver superior visuals with a much less expensive projector.
By following these six steps, technology leaders in houses of worship can maximize the rewards of today's front projection technology without sacrificing the aesthetic value ambient light brings to each service.
Jenny Brust is business development manager for AccelerOptics, www.capturedisplays.com. Joe Baer is regional vice president of AVI Systems, www.avisystems.com.