Features

Weight

An essential consideration in selecting the ideal projector is its weight.

• If the user travels a lot, they probably want the lightest, most portable machine available that still fits the resolution and brightness needs.
• If the user travels occasionally, requires improved performance and are willing to carry a heavier unit, the 2kg+ weight projectors may be suitable.
• If the user doesn't intend to travel with the projector but still wants the ability to move it around the office, from classroom to classroom, or to take home on weekends, the 3-5kg range may be suitable.

Finally, if the projector will be used in a specific place and there is no need to move it around, weight is not an issue so the selection should be made on other cost and performance factors.

Ansi Lumens

This is a measurement of brightness for a projector. ANSI (American National Standards Institute) is a recognised, standardised method of measuring how bright a projector is.

One lumen is equal to the approximate level of brightness produced by a single candle. To measure the brightness, measurements are taken at 9 points on the screen, three each down the middle and to each side. These measurements are then averaged out to produce the lumens rating of the projector.

Some vendors rate their projectors by Lumens, this is not the same method and can be misleading as it depends more on the brightness in the centre of the screen which naturally will be brighter than the sides. As a rule of thumb, the larger the screen size, room size or distance of the projector to the screen, the higher the lumens rating will need to be.  Many other factors will effect how bright a projector will need to be such as the amount of ambient light in the room, is it south facing and are there curtains/blinds etc?

Resolution

The resolution of a projector relates to the number of pixels in the image, the larger the number the better the image will be. Over the last couple of years the cost of entry level projectors has dropped considerably making higher resolutions more affordable.

When choosing the projector one should consider the resolution of the input device. The ideal scenario is to match the 'native resolution' i.e. the resolution of both the projector and the input device should be the same. There is little point having a true HD projector if the input device or the content itself is only VGA.

Increasingly people are wanting to use laptops with projectors, many laptops have a native 16 x 10 wide format screen. Therefore it would be advisable to use a wide format projector. The resolution of a wide screen projector can easily be seen in the resolution chart below as they are pre-fixed with the letter W. Therefore WXGA is the wide screen version of a standard XGA projector.

• SVGA, or 800 x 600
  SVGA projectors are great for those on a tight budget, since prices have dropped dramatically in recent years. While most computers still output in higher resolution, SVGA can be a good option for power point presentations or other applications that are not heavily dependent on detail.
• XGA, or 1,024 x 768
  XGA projectors have come down in price over the past few years, and have become the budget standard. Most computers still output in native XGA, so matching an XGA projector to your computer ensures you won't lose any detail.
• SXGA, or 1,280 x 1,024
  SXGA products are high resolution and notably more expensive than XGA. These products are targeted for high end personal computer users and low end workstation users. They are used primarily for command and control, engineering and CAD/CAM applications where acute resolution of small details is important.
• SXGA+, or 1,400 x 1,050
  SXGA+ projectors are becoming more popular and there are several offerings available in both budget and high HD.
• True High Definition or 1920 x 1080
  Increasingly this is being adopted by home cinema projectors; however these have low Lumens ratings so are often not bright enough for commercial usage. 1080 projectors are increasingly appearing in the commercial sector but they are currently the domain of the high end market.

Aspect ratio

When 4:3 and 16:9 formats are discussed it is about the rectangular shape of the video image, or what is called its aspect ratio. A standard TV has an aspect ratio of 4:3. That means the picture is four units wide for every three units of height. The HDTV standard is 16:9, which is 16 units of width for every 9 units of height. So HDTV's 16:9 is horizontally wider than regular TV, which by comparison looks almost square.

The problem with this is any given projector or TV comes in its own native format--typically either 4:3 or 16:9. On the other hand, movies and video come in many different aspect ratio formats. TV programs and videos intended for regular TV are produced in 4:3 format, often denoted "1.33:1" since 4 divided by 3 = 1.33. On the other hand, programs made for HDTV are in 16:9 format, which is 1.78:1 (16 divided by 9 = 1.78). However, these are not the only two formats that video material comes in. Movies, music videos and other content on DVD come in a variety of formats including 1.33, 1.78, 1.

Contrast Ratio

This is the difference between the darkest and lightest images on the screen. The higher the contrast the greater the impact will be. However there is an issue with the way contrast is measured; currently there is no standardised method. Some vendors are trying to get the ANSI method of measurement adopted, this involves using a series of black and white squares similar to a chess board, however until such time as a method is adopted contrast rates may not provide a true reflection of the quality of the image.

Lenses and Throw Ratios

As with a camera there are many different types of lenses available some designed for use where the projector is a long way from the screen (long throw) and others for when the projector is very close (short throw) and all distances in between.

Whilst most projectors come with a lens fitted and with no ability to change it there is an increasing sector that has a range of lens options. If the installation requires the projector to be located in a certain place it is vital that the projector has a lens capable of focusing on the size of screen you require. To do this the ""throw ratio"" needs to be established.

The throw ratio is often printed in a form such as 0.8:1 or 1.8 - 2.3:1 and it is worked out by dividing the distance the projector is placed from the screen by its width. Therefore if one places the projector 4 metres away and the screen is 2.5m wide the ratio required is 1.6:1 translated this means that for every 1.6m away from the screen you will get 1m width of image. Most lenses will be zoom, either manual or mechanical this means that the lens will have a range of distances over which it will create the desired image size. It is best policy to try and get a lens that easily covers the ratio that you need, try to avoid having the requirement right at the edges of the lenses capabilities as there is often a 5% error margin.

To use our example of a 1.6:1 lens a good lens to buy would have a ratio of 1.4 - 1.8:1

Keystone Correction

If a projector is placed directly perpendicular to the screen then the image will appear the correct shape however in reality portable projectors are often placed on table tops and angled up to the screen whilst ceiling mounted projectors are angled down. As a result, for instance, the image from a projector aiming up towards a screen will appear slightly triangular as the lower part of the image will hit the screen before the top of the image, as a result the top has a greater distance to travel and appear to be wider. Keystone correction is simply a function of the projector where it will either automatically or manually adjust the image to square it off, so that it appears as though the projector was directly in front of the screen.

Many projectors will have Keystone Correction (some auto keystone), often listed as a number followed by a percentage sign and the letters V and or H. i.e. 45%V 30% H, this shows the amount of correction the projector can handle (the higher the better) and if the correction is vertical (V) or Horizontal.

There are two ways to adjust for Keystone. The most popular method is digital keystone correction which uses the projector to change the image digitally, this produces results which are adequate for standard installations, however it does result in some image quality loss. Manual keystone correction uses lens shift to physically move the projector lens to compensate - this produces better quality results and is found mainly on more expensive projectors.

Networking

Many projectors can now have network control either by hard wiring or increasingly via Wi-Fi. In some cases the projector will have this capability built in whilst in others it will be via the addition of a network card.

It is important to clarify exactly what level of network access you will require when specifying a networkable projector. In many cases a projector described as 'networkable' will have limited functionality, often it will allow remote access to ascertain how many hours the lamp has been working or other basic functions. Increasingly however it is becoming possible to assign an IP address to an individual projector, this allows full web access over LAN and in some cases WAN and will enable a user to send a presentation to a projector on a remote site amongst other more advanced features.

Home Cinema Projectors

A rapidly growing sector of the projector market is for Home Cinema Projectors. Typically these are used to project DVDs.

Home cinema projectors tend to have high contrast ratios but low brightness as they tend to be used at home where the darkness of the room can be controlled.

• 854x480:
  This is the least expensive and lowest resolution on the market. It is designed for optimum display of standard definition material in NTSC countries, since both NTSC television signals and standard DVDs contain 480-lines per frame of video. An 854x480 projector can display 480-line video without any vertical scaling, so the picture will look its sharpest.
• 1024x576:
  There are few projectors in this resolution these days but they can still be found in the used projector market. They were designed for optimum display of PAL/SECAM video, which contains 576 lines per frame. They have little practical use in NTSC countries, but if used in a PAL or SECAM country, these can be inexpensive alternatives that are ideally suited to viewing standard definition PAL/SECAM video.
• 1280x720:
  This is currently the most popular home cinema resolution and matches that of the 'HD ready TV market'
• 1920 x 1080p:
  Increasingly common this is otherwise known as True High Definition, the price point of these projectors is now beginning to fall making them more obtainable.

I have never bought AV. How do I buy a projector?

Firstly don't worry, Maverick have a team of experts in all forms of projection who are here to provide you with the assistance you need.

Here are a few simple steps...

1. What does the customer want to do with the projector? Simple question, most people will want to do basic projection - a mixture of power point, spreadsheets and some video. In this case both DLP and LCD projectors will be suitable.
2. What aspect ratio is required? Wide screen or 4 x 3? Most projectors are currently 4 x 3 so this will give the user a much better choice and range of prices. However if one is using a laptop which is widescreen or mainly projecting spreadsheets then a widescreen projector may be advisable.
3. What lumens rating is required (brightness of the projector)? To establish this one needs to know what type or size of room is the projector going into? A small typical office or training room/classroom will not require a very bright projector, typically 2000 - 2500 lumens. However there are other factors to consider such as how bright is the room, is there lots of windows, skylights etc? These can have a dramatic effect on the amount of ambient light and the lighter the room the brighter the projector will need to be. Other factors to consider will be the size of the screen and the throw distance, as these increase so also will the need to increase the brightness of the projector. If budget allows it is always preferable to select at least a 3000 ANSI lumen projector.
4. How big is the image user requires? This will effect what type of lens is needed, the customer may want a really big screen but in reality will be limited by the height of the room, something often forgotten.
5. What is the max and min throw distance available (how far away from the screen is the projector likely to be). In many rooms there will be few physical limits to where the projector can be placed, this makes it much easier to source a projector.