AV Installs have been providing projectors and projector installation services for over 17 years now. We have seen allot of changes in that time. There are many things to consider when buying a projector dependent on your needs. It would be impossible for us to write a guide for every application. In this post we are going to cover the 4 fundamental basic things to think about when buying a projector.

• Brightness ( Lumens )
• Native Resolution
• Technology
• Throw Ratio

Brightness

Projectors brightness is measured in lumens which is a standard measurement unit of brightness. In the industry we call this ANSI Lumens for American National Standards Institute. For instance the light source from a candle measures 14 lumens. One of the most important factors to what brightness projector is going to be ambient light. In Short the darker the room the less lumens the brighter the room the more lumens. As a general guide most home cinema, office and learning spaces will require 2000 to 4000 lumens. When it comes to large screen projection in halls and lecture theatres you will need more lumens. The bigger the image and the brighter the space the more lumens you will need.

Contrast is another thing to note that can effect perceived brightness. Contrast is the difference between the darkest dark and light light. The larger the ratio the greater the contrast which makes things appear brighter.

Native Resolution

Firstly projectors native resolution is the actual resolution on the panel the most that it can possibly be. Things have changed allot here over the past few years and projectors are available in full 4k HD. Secondly the main thing to look out for here is that HD ready does not mean HD, 4k ready does not mean 4K. Always check the native resolution as this will be the true resolution that you will get. If the native resolution is 1080p full hd and its 4K ready it just means it will accept the 4k signal and scale down to full hd.

Below is a list of the most common computer and video resolution’s along with the pixel counts working from the lowest to highest resolutions .

• (VGA) 800 x 600
• (XGA 1024 x 768
• (WXGA) 1280 x 768
• (FullHD) 1920 x 1080
• (WUXGA) 1920 x 1200
• (QHD) 2560 x 1440
• (UHD) (4K or Ultra High Definition) 3840 x 2160

Technology

Projector technology has improved considerably, for instance the old days of a red, green and blue bulb on a projector the size of a house have long gone. As a result we have a broad range of projectors now that cater for pretty much every need. Firstly lets look at the three main technologies available on the market at the moment DLP, 3LCD & LCOS.

DLP ( Digital Light Processing) was invented by Texas Instruments and first used in mainstream projector back in the mid 1990,s and is still used extensively today. The DLP chip is made up of thousands of tiny mirrors that tilt to reflect different levels of light. This light is then passed back through a spinning color wheel then on through the lens.

3LCD was invented in Japan by Epson in the 80,s and used in projectors from the late 80’s onwards. It works by white light which is split using mirrors into red, green and blue. Each mirror then reflects each coloured light to its own LCD panel which receives electric signal to control light. All three chips then combine in a dichroic prism to produce the final image that passes through the lens.

LCOS projectors are almost a combination of both, it uses the reflective technology found in DLP, However it uses crystals not so dissimilar to LCD to control the light. This offers a three chip system delivering blue, green and red separately rather than a spinning wheel. The result is a more dynamic range of colours and a larger spectrum from light to dark. LCOS is generally used on higher resolution installation projectors.

Throw Ratio

Throw ratio in short is how far back the projector needs to be in relation to the desired projected image size. Using simple throw ratio equations you can work out several useful factors. Firstly if you take the width of your screen and multiply it by your throw ratio you can get the throw distance. Another useful equation is take the projector throw distance and divide it by the screen width you will get the throw ratio. This is essential for the correct projector installation

Out of the box projectors are available with a variety of lens ratios including Ultra Short Throw. Office and Home Cinema projectors generally have a standard throw ratio. Installation projectors have interchangeable lenses so they can accommodate nearly all scenarios with the correct lens.

If a projector had a 1.5 ratio lens it would need to be 1.5 meter back for every 1 square meter of projection. If we take a 2 meter wide screen the projector would need to be 3 meters back

More Info

If you would like to read more about the history of the projector in allot more detail then please take a look at our blog post on the evolution of projection.

Professional Projector Installation Services

AV Installs have been providing professional projector installation services for domestic, commercial and education customers for nearly 20 years now. We have a wealth of knowledge and expertise which enable us to provide expert advice on any project. For more information please get in touch with us today we would be more than happy to help