Home Cinema Projectors and Installation
Over the last few years home cinema projector technology has evolved tremendously with huge improvements in picture quality, contrast, colour and brightness levels. The arrival of full high definition has really made projection come into its own. Full HD images on a 42” TV look great but on a 9ft wide screen the effect can be incredible.
At Home Entertainment Direct, we supply/install many different projectors from leading manufacturers such as Epson, Optoma, JVC, which are chosen to perfectly suit the particular application, room layout and budget
Projector installation – Aligning the projector
Aligning the projector can be the most tricky part of home cinema set-up. To help align the projector many machines have an alignment grid that can be activated in the settings menu. This fills the pixels at the very edge of the image so you can be sure you are filling the screen correctly. High end projectors have a vertical/horizontal optical lens shift which allows movement of the image to screen location without having to move, angle or tilt the projector. For best results the projector should be positioned opposite the centre of the screen and at a 90 degree angle to the screen to avoid image shape distortion. When the screen is fixed to the front wall it relies on the front wall being perfectly square to the room, which is often not the case and will 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. Generally the projector lens will be vertically positioned approximately 5cm to 30cm above the top of the viewable part of the screen, with the projector sitting upside down on a ceiling bracket. A good quality bracket is recommended with twin screw adjustments to allow very fine 360 degree tuning of projector angle to give perfet alignment.
A projector with vertical lens shift can also be mounted the normal way up on a shelf. Depending on it’s range of lens shift it can be fixed anywhere within the area of the screen. A vertical lens shift projector should always be kept level and the lens shift used to move the image, do not tilt the projector.
Another very important consideration when choosing a projector for a cinema room is the throw ratio of the projector lens. 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 a number range and varies between different makes/models of projector/lens. The number range will indicate the closest and furthest distance that a projector can be placed from the screen. 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 of the projector is 1.5 – 2.0:1 and you have a 3m wide screen.
3m x 1.5 = 4.5m which is the closest the front of the lens can be from the screen.
3m x 2.0 = 6.0m 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 should be some margin for error.
Therefore make sure the throw ratio of the lens suits the room size for the particular projector. The more expensive projectors tend to have a wider throw ratio or options for specialist short throw or long throw lenses for overcoming any issues.