What to look for when buying a home cinema projector

Home Cinema Projectors and Installation

Over the last few years home cinema projectors have probably developed faster than any other piece of AV equipment. They have come along way since the large 3 lens washing machined sized eye sore on the ceiling of the local pub showing a blurred football match. The arrival of full high definition has really made projection come into its own. Full HD on a 42” plasma is one thing but see it on a 8ft wide screen is another. The way a projector produces the image has greatly improved, technology like Texas instruments DLP chip and JVC’s D-ILA wire grid are now producing film like quality images with a very high native contrast.

Themescene HD83 3d Home Cinema Projector

To make matters confusing there are a huge array of makes and models of projects on the market with very much exaggerated specifications. Most of these machines are modified conference and presentation models that have been marketed to the ever growing home cinema market. My advice would be to stick with a company that solely manufactures projectors or that has a professional broadcast background. Not only do they have the edge on performance, most of these companies have only a small UK based division. This means any problems you might have are dealt with efficiently and there is always some good technical staff on hand to talk to. Sim2, JVC and Themescene all make some superb projectors at various price points and all have small setups in the UK dealing with their sales and technical.

So lets look at a projector and the best way to install it.

Projector installation - Aligning the projector

To help align the projector most machines have an alignment grid that can be activated in the settings menu. This fills the screen from edge to edge. The horizontal plane of the lens should be placed in the centre of the screen with the screen and projector at a 90 degree angle to each other. As the screen is fixed to the front wall it relies on the front wall being perfectly square to the room, this is often not the case but will only produce a very slight discrepancy in the picture shape. This can be compensated by slightly overlapping the image onto the black borders of the screen. This is quite normal and common practice. Many Hi-End projectors now have optical lens shift, this allows you to offset the project from the centre of the screen within the limits of the lens shift. The projector should still remain at 90 degrees to the screen or the image will be distorted.

The vertical position of the projector should be approximately 5cm to 30cm above the top of the viewable part of the screen. The perfect position

Home Cinema Installations and help in installing one

If your projector has a motorized or manual lens shift these positions can be a lot more flexible. The JVC has vertical and horizontal lens shift but you must mount it within its limits. If your projector is off centre don’t twist the projector to move the image across, keep it square to the screen and use the lens shift. The same goes for the vertical, keep the projector level and use the lens shift to move the picture up and down.

It is perfectly normal for some of the picture to overlap slightly on to the screen borders as there is often slight discrepancies to how square the screen is to the projector.

The distance the projector can be placed from the screen is governed by the lens throw ratio. This is stated on the manufacturers specifications, it has two numbers. The lowest will show the closest the projector can be the higher number the furthest way it can be. To calculate this you take the width of the viewable part of the screen and times it by these numbers.

For example:
The throw ratio is 1.8 – 2.2:1 and you have a 2.3m wide screen.
2.3m x the lowest number 1.8 = 4.14m which is the closest the front of the lens can be from the screen.
2.3m x the highest number 2.2 = 5.06m which is the furthest the front of the lens can be from the screen.

The projector can be placed anywhere within these measurements but it is advisable not to place the projector on the limits of these distances as there can be up to a 5% discrepancy in the lens specification.

Projectors

This is the JVC X30, it is a superb projector and has had some fantastic reviews in the press. It produces an amazingly good 2D image and has the added bonus of being a 3D machine, Avatar looks simply stunning in 3D on this projector! A Hi-End projector like this will probably

In the majority of installations the projector is ceiling mounted, the fixing points for the bracket are on the underside of the machine so the projectors sits upside down and the picture is rotated within the settings menu.