Tutorial - Perfect projection

This moth’s tutorial focuses on getting the most from your projection environment. Chris Mellow from UK distributor Midwich and Charlie Fenton, product application manager from Panasonic UK, share their wisdom on the key points to consider when selecting and installing a projector.

The display system is often the heart of a commercial AV system, especially in the corporate or education environment, where the information displayed is the centre of discussion. You can have all the great content in the world, but if your projection solution isn’t up to the mark then the audience will be distracted by poor picture quality, may not be able to make out important detail or in an extreme case, be actually physically affected by eyestrain.

For all these reasons it’s vital to get it right. The physical installation of a projector is handled elsewhere in this issue, so it remains to discuss the factors that will lead to a successful selection of a projector and set up of the room.

The room

Obvious as it may sound, the intended space will have a significant on your decisions. Not everyone is fortunate to have a purpose built room designed with a projection system in mind so there will be constraints on where you can physically position to projector. However these are not as big a problem as they once were, thanks to the advent of innovations such as short throw projectors, wide screen models, wireless technologies and versatile lens options. These mean that almost any situation can be catered for.

In the case of a physical obstruction in the ceiling there are three options available:

1) Mount the projector on a desk or other surface – this isn’t ideal as it presents a security issue.
2) Make sure you purchase a projector with horizontal keystone correction or lens shift, enabling you to mount the projector of centre.
3) Purchase a short throw model, except in really extreme cases this will solve the problem with projectors now available that will produce a 70” screen from as little as 5cm from the lens.

Note that physical lens shift is infinitely preferable to keystone shift since the processing done during keystone correction will lead to a degradation in image quality.

Lighting conditions are also a consideration. The most important factor is the expected ambient light level in the room. Are you planning to use the projector with the lights on or off? In most cases if you are only going to use the projector with the blinds closed and lights off you will rarely need more than 1500 ANSI lumens, however if you turn the lights on and open the blinds the image will become considerably faded. In this case you will need a brightness in excess of 3000 ANSI lumens.

The size of the screen will also affect your brightness – the bigger the screen, the more brightness required.

Technical requirements

Having looked at the space available, the next thing to consider is what technical and functional requirements you have of the system.

One of the biggest factors is what data you are planning on displaying. If you are just going to be showing PowerPoint, do you need more than SVGA resolution? If you are using spreadsheets with lots of data then you will almost certainly need a minimum of XGA or possible even SXGA.

If you are intending to use the projector for a video conference, or fly in a number of PIPs you will need even higher resolutions to maintain picture quality.

Inputs and source types are another key point. Cabling is sometimes overlooked when selecting projectors. You need to consider the existing infrastructure – do you need a fresh installation? If you are replacing a projector, can the new one be mounted in the same place? Wireless projectors are now becoming more common, and with new Window Vista-based wireless solutions it has become much easier as you no longer need to do the software installation, the projector simply connects to an existing network.

The final technical point is the necessary screen size. As previously mentioned this has a bearing on the brightness you need, but also the resolution. Aspect ratios are also now a key point with 4:3, 16:9 and 16:10 all available, if you replace a legacy 4:3 projector with a 16:10 model, you’ll need a new screen too!

Decisions, decisions

So having thought about the various factors, there are a few key decisions that need making.

Which projection technology? This discussion could run to an entire issue, but in very broad terms LCD offers richer, more natural colour, however with the new DLP chipsets that are being used by brands such as Panasonic this is becoming less of an issue. The main advantage of DLP is that the projectors can run for longer periods of time. Several high-end models are now guaranteed for 24/7 operation. For really accurate colour reproduction, you may wish to consider an LCOS based product.

Lastly the screen itself bears thinking of. In most cases, a matte white surface will do, but with companies such as Da-Lite offering upwards of 30 different surface options there is something out there for everyone.

Feedback and comments are always welcome, if you have anything you’d like to add to the subject, please email the InAVate inbox at the usual address: inavate@imlgroup.co.uk

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