Video projector primer

The sea of choices in video projectors, projector technologies and combinations of features is almost overwhelming. In planning the purchase of a projector, it is important to determine the specific needs of a particular installation in order to determine which projector best fulfils them – and it is always a good idea to develop a relationship with a systems designer or integrator to assist in making those choices.

Before getting into any of the specifics, however, a simple note of warning – while they may be appealing reading initially, be wary of the promises made by consumer electronics retailers – typically, the products they have to offer are not up to the performance demands required in a professional setting, including a house of worship.

The prevailing technologies for projectors are LCD (liquid crystal display) and DLP (digital light processing) and while each has its own specific strengths and weaknesses, practically speaking, they are pretty much on equal ground. Another available technology, LCoS (liquid crystal on silicone), could be thought of as a kind of hybrid of LCD and DLP technologies. For projectors in fixed installation applications, connectivity for networking, remote monitoring and control may be an important consideration.

Why are lumens important in determining the type of projector to use in a given application?

Scott V Burkhardt, marketing programs specialist, visual communications systems division, Canon USA: Lumens are typically either the first or second ‘spec’ listed in a projectors product features because, without the right level of brightness, an audience will struggle to clearly see whatever content is being displayed – which is, of course, a very bad outcome and defeats the purpose of employing a projector.

The first question to determine before considering lumens is what that application will be. Generally speaking, if the application is a large room – like a lecture hall or house of worship that has ambient light and a longer throw distance and larger screen size – then a projector with a higher brightness rating will be needed. This is opposed to a smaller setting, like a home theatre environment, where ambient light can be minimised (if not eliminated) and the throw distance and screen size are much smaller. In this type of application the brightness rating, while still important, would not be as key as the contrast ratio.

When reviewing the brightness of projectors, a good note to remember is that higher brightness equals more flexibility. For example, a 3,500 lumen projector, which is a good amount of brightness, can likely be used in both portable (classrooms) and installation applications (worship services). However, for many houses of worship, a brightness rating of greater than 3,500 will be needed to offset the ample ambient lighting from windows, ceilings and so on. Of course, as brightness increases, so will the price tag.

Besides lumens, what other things should be considered when selecting a projector for use in worship?

James Chan, senior director, marketing, Mitsubishi Digital Electronics America: Projectors are an investment, and before you go on a shopping spree, there are a few basic concepts you need to understand about projectors and how they are marketed. Projectors are categorised by weight, marketed by brightness, hyped by resolution, and sold mostly because of price.

Weight categories

Projectors are categorized into the following weight levels:

Weight Category vs. Targeted Markets or Applications

Contrast ratio

For the majority of projector users, brightness is the most important factor, but for someone displaying more movies and videos, contrast ratio is important. Contrast ratio pertains to the ratio of the brightness of the brightest white, versus the darkness of the blackest black. The higher the contrast ratio, the deeper and richer the colours are displayed. Although there is also an ANSI (American National Standards Institute) standard of measuring contrast ratio, most manufacturers opt for the de facto industry standard called the Full On/Full Off measure. Using the same 40-inch diagonal 4:3 aspect ratio screen, a white screen is projected, its brightness measured from the centre, and then a black screen is projected, and its brightness measured again from the centre – the contrast ratio is the ratio of between the two measurements.

What are the different resolutions available? And why would one be needed over the other?

Edgar Jimenez, product manager, Epson America: There are a widespread number of resolutions including SVGA (600 x 800), XGA (1,024 x 768), SXGA (1,280x1,024), SXGA+ (1,400 x1,050), WXGA (1,366 x 768), and WUXGA (1,920 x1,200). The rationale for adopting increased resolution is that most PC and Mac notebooks, as well as wide screen video equipment, are driving the need to see the display in its native resolution. In order to display the images correctly in sizes such as 1,280 x 800 or 1,920 x 1,080 are required, which mean WXGA and WUXGA projectors are necessary.

What about aspect ratio? What are the advantages (and disadvantages) of the different aspect ratios? And what are the determining factors in choosing which one to use?

Edgar Jimenez: The predominant aspect ratio is XGA (4:3), however WXGA (16:9) and WUXGA (16:10) are also gaining in popularity. As with resolution, the rationale for adopting wider format aspect ratios lies with PC and Mac notebooks, and wide screen video equipment.

Sander Phipps, senior product manager, professional displays, Sony Electronics: The aspect ratio should ideally follow the aspect ratio of the source. If image magnification (IMAG) is one of the main applications, then the projector should have the same aspect ratio as the cameras used. As the availability of HD content becomes much more common most new installations are wide aspect ratios.

How can factors such as lamp life and energy efficiency be determined? And what maintenance factors should be considered?

Chuck Collins, VP of commercial A/V, Digital Projection: Most manufacturers make a statement as to what their projectors’ lamp life is, and the power consumption of their specific projectors. When determining maintenance costs, one needs to determine how often the projector is going to be used and then divide the expected lamp life by the number of user hours to determine how many lamps will be needed in a given amount of time. A lamp replacement budget can then be established. The only other typical maintenance is to replace air filters in the projector as needed.

Are there any other things that should be considered when selecting a projector for a house of worship?

Sander Phipps, Sony Electronics: Ergonomic features, such as ease of use and control, are also important, as non-technical people may be asked to use the projector in houses of worship. Also, no matter how good the projected image looks, if the projector’s noise distracts from the service, it’s not adding to the overall A/V values you’re trying to produce.

Scott V Burkhardt, Canon USA: It will depend greatly on the application of the projector/s. For those projectors that will be used portably in multiple settings the important features will likely include:

Auto setup – how quickly will the projector function and will it automatically sharpen the focus?

Noise Level – how much sound is produced when the projector is running? Will it interfere with the ability to hear?

And for those projectors that will be installed, the important features will likely include:

Filter System – how often will the filter/s need to be changed? Does the projector employ some type of advanced technology to minimise this? (This can be key for many installed applications because access to the projector can be challenging.)

Lens Shift – can the lens be shifted to centre the image on a screen?

In summary, all of the features discussed may have different levels of importance in any specific application. This guide should make sense of some of the terminology used, and highlight critical consideration. If in doubt, it is best to speak with an A/V professional to determine which projector will make you shine.

www.canon.com

www.mitsubishi-presentations.com

www.epson.com

www.sony.com/professional

www.digitalprojection.com

Published in Worship AVL Asia Autumn 2009