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Buying a Data / Video Projector

Many churches have long since moved to using data projectors / laptops for the display of their songs and information for their services. Here are some of the factors involved if you are looking to purchase / upgrade a data projector.

First of all, don't be fooled by manufacturer's claims and counter-claims. Like anything, you get what you pay for - and equivalent products with the same specifications, often produce wildly different results. So, do your research, ask people who know and read independent internet and magazine reviews.

This is done in Alphabetical Order. Some information has come from other internet sites, much has come from personal knowledge. I hope and pray this is a useful guide with informative and accessible information.

Audio Support

Do you want your projector to output sound? If so, you'll need to get a projector with the largest amount of watts of sound as possible. Your alternatives are to hook up the original source (for example an mp3 on the laptop) direct to an amplifier, or your church PA - or get a projector with the option to act as an output for sound. So, you'd need to look for an 'audio output' on the projector. These outputs are generally what are called, 'mini jacks'.

Brightness

Brightness is measured in what is called 'ANSI lumens'. You should get this rating up as high as possible, depending on the following factors: size of the room, amount of natural light in the room, amount of other lighting sources (such as artificial lighting) and the screen size. The higher the ANSI lumens rating, the higher the brightness will be from the projector. It is also important that the brightness is uniform across the whole image (from corner to corner). Bear in mind that different kinds of bulbs produce different levels of brightness, even with the same 'ANSI Lumens' settings - with halogen being less bright than metal-halide, for example.

So what size lumens do you need? Click here for a handy online guide I found. Basically, you should get a minimum of 1000-1500 lumens. If you have some ambient light around, think more in terms of 2000 lumens. If you're in a church of over 100 with few lights, then think 2000-2500 lumens. If you have some ambient light in a larger church, go for 3000 lumens. If you're in a situation with a lot of people with very bright lights, you'll need 5000+ lumens.

Remember that 'real world' performance of vide projectors may be different to that written down, and that similarly specified projectors may produce radically different results. Check around for reviews before buying.

Contrast Ratio

This is the range / difference between the brightest white and the darkest black colours that your LCD TV displays. It's an important factor beyond brightness when choosing your projector - your blacks should be black, your whites should be white and all the other colours in between should be accurately represented. The colours should be accurate, without other colours 'bleeding' (getting into) other colours, especially the whites. Contrast ratios range from around 1000:1 to 6000:1. Commonly they are in the 400:1 to 2000:1 range.

(For example, Epson projectors have lower contrast ratios as they are usually LCD based. DLP projectors tend to have higher contrast ratios, due to the nature of the technology used).

Genlock

Synchronizing signals between two video sources, which is necessary when overlaying computer graphics on an image from DVD, camera, or videodisc player. A video mixer has the capability in-built already. We use the Edirol V4 video mixer and can highly recommend it for low to medium applications and settings.

Inputs and Outputs

How do you want to connect up your video projector? There are differing levels of quality that projectors can accept. These include (from top to bottom in terms of quality): HDMI (high definition multimedia interface), DVI (digital video interface), RGB / VGA (a 15 pin plug that is most commonly found on PC laptops), Component video (3 separate leads of red, green and blue), S-Video (separating the signal into chrominance and luminance), and composite (also known as RCA - the lowest quality of all).

Your problems may be that most PC laptops don't output DVI (unlike Macs). Also, many PCs don't have in built s-video ports as standard (unlike Macs). So your most likely option will be what has become referred to as 'VGA' leads (although this term isn't strictly accurate). This produces a fairly high quality image.

Some projectors will also output a signal (for example, if you want to link 2 projectors together from one projector). However, you must input to the first projector via 'VGA', if you wish the second projector to be linked up via 'VGA'. Be aware of that. Another way to link more than one projector, is by using a genlock or a video mixer.

Keystone Correction

The facility to change the projector image to produce a rectangle image to correct the effects of the image from a projector distorting. You need to get a projector that can correct both horizontal and vertical keystoning. Keystoning can been seen in the images below..

keystone 1

keystone 2

Lamp Hours

A standard lamp lasts for about 2000 hours of projecting. However, lamps cost between £150 and £500 or more, so consider carefully how many hours you can realistically expect out of your projector, as this will save you money in the long term!

Lens Shift

Lens shift gives you the ability to move the projector lens - left, right, up or down, from within the projector housing. This adjustment can be made either manually with dial or joystick, or by the projector, using the menu buttons. This gives you even more options in placing your projector in your room, and therefore overcoming any objects in the way of the projected image! Lens shift can also fine-tune the position of the projected image on your screen.

Rear Projection

Projecting an image through a translucent screen material for viewing from the opposite side. This method of projection is also an option for home theater use in large spaces.

Resolution

As mentioned elsewhere, another way to think of resolution is by thinking of how many dots (called 'pixels') go to make up the image. The higher the amount of pixels, the higher the resolution and therefore the more detailed the image.

Basic projectors fall into two categories - SVGA (800 x 600 pixels) or XGA (1024 x 768 pixels). The next setting up is called SXGA and has a resolution of 1280 x 1024 pixels. You also have a setting of UXGA which displasy an image 1600x1200 in size (if your computer can handle this resolution).

What you should try and do is to match your computer screen / laptop screen resolution, to the resolution of the projector. You will need a lead that can handle the resolutions as well. We'll think about that later.

(If you see resolutions such as WSVGA (1024 x 576 pixels), or other resolutions with a 'W' in front of the name, the 'W' stands for 'widescreen'. These are most common in home theatre systems so we don't need to worry about them too much - they produce the 16:9 aspect ratio associated with movies and most TV broadcasts).

HD projectors tend to have resolutions around 1920 x 1080. However, there is more than one way of having and viewing HD, so just look around and decide what fits your needs. Remember that with the higher resolution projectors, you need specific leads that will carry the quality of the picture eg HDMI leads (and the original source needs to be HD in order to see true HD images).

If you'd like to see a faked example of how higher resolutions usually mean a better picture, these 2 images may help..

Image one (click to see in new window) - has a clear image with the flowers in background in focus.

Image two (click to see in new window) - has a more blurred feel to it, with things not appearing so 'sharp'.

'Throw' of the Lens

Think about the kind of building you have and the uses you'll have for your projector. Do you need one that can produce a large image nearby to the screen, or do you want a lens that can is further back and 'throws' or ('displays') the image from a long way from the screen.

Type of Projector - LCD or DLP

DLP stands for 'Digital Light Processing' and produces a full colour image from the light. LCD stands for 'Liquid Crystal Display' and creates red, green and blue images from the light which combine together to make the colour picture. This is the technology used in laptops and LCD TVs etc. There's much debate about the upsides and downsides to these 2 technologies. Many suggest that in larger situations, LCD is the way to go.

Weight

This is a factor for many. Is your projector going to live permanently in your church, maybe attached to the ceiling via a bracket? Or is it going to be used in different places at differing times? If so, you may want to get a portable and lightweight projector. Bear in mind that the larger projectors offer better value for money - more 'bang for buck' so to speak.

Zoom Lens

A lens with a variable focal length. This means you can adjust the size of the image on a screen, by adjusting the zoom lens to move the projector image closer or further.

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