Thread: Home Theatre Blues - Part 6 (b): Choosing the Projector

Introduction
Almost everyone must have seen a projector - I mean the boardroom projector and not the cinema projector that one finds at cinemas/multiplexes. A projector is another means to display video at home. Though not very common, projectors (at home) are slowly getting popular. A hardcore home theatre enthusiast will have a projector or aim for one sooner or later.

Why should a projector appeal to you? The reason is very simple - a huge display image that very few TVs can match and at the fraction of the cost (size per size). For Rs. 65K to 100K you may get to buy a Full HD TV (LCD/Plasma) that displays an image that is 40" to 46" diagonal. A projector costing Rs. 60K can display an near-HD (720p) image anywhere from 80" to 120". For Rs. 150K to 200K you can get a full-HD (1080p) projector. The size of the image is only limited by the size of the room (length and width of the projection wall).

So what gives?
Before one gets excited by these numbers, one must be very objective about the pros and cons. A projector is not for everyone.

First of all, the projector will need a dedicated viewing room. One needs a flat wall or a projector screen. Secondly, you will need an almost dark room. The slightest ambient light will spoil the projection (and I will come to that later). Thirdly, the projector needs to be installed properly. The ceiling mount is the best but if that is not the case then at least at a height of 7 feet above the ground. Fourthly, it needs to be perfectly perpendicular to the projection surface. And finally, you may need long cables running from the projector to the source equipment.

And then again, a home projector is best suited for cinema and not for TV. But this is my personal opinion. I have a projector at home but it turns me off when I am watching TV on it. Maybe it is due to the poor picture quality (PQ) of the source (DishTV DTH).

But if you have managed all of the above, the projector can blow you away with the sheer pleasure.

Projector Classes
Before you head off to the market to buy a projector, note that there are two classes of projector and within each class.

The first class is the boardroom projector. This projector, as the name suggests, is meant for the office boardrooms, conference halls, education halls, etc. This projector has high brightness (measured in ANSI lumens) and low contrast ratio. This is because such projectors are used to display presentations, slides, etc. which are predominantly text or small pictures. The source is already strong in contrast. Moreover, the ambient light may be high in the boardroom. Hence such a need/feature. Such projectors are totally unsuitable for the home.

The second class, i.e., the home projector is meant to display cinema where the contrast in content is low and the blacks are high. A boardroom projector will wash out the blacks and will not be able to display the contrast clearly. When it comes to home theater projectors, brighter is definitely not better. What you want is a projector that produces enough light to fill your screen with good contrast, but not so bright that it creates eye fatigue when viewed for any length of time. The home projector main features are therefore high contrast and low brightness.

One must consider "what is black" in a projection. A projection is a light emitting from a source. A black simply means no light. But in a projector, there is always a light. So if the projector lamp is extra bright, the black will appear as grey. It still does even for the best projector today but we have to control this by having a near dark room.

Projector Types
The two main projector types of whichever class (boardroom or home) are based on the technology. The first type is the LCD projector while the second type is the DLP projector. I will not go into too much technical detail here. You can read all about it the dedicated site ProjectorCentral.com.

You can choose either an LCD or a DLP projector. Just read the reviews about the projector before you buy. The above site is a must visit for this purpose.

Important Home Projector Features to be considered
Your budget will mostly decide the projector but within those constraints, the following order should be your choice of emphasis:

• Contrast Ratio: Choose the projector that has high contrast ratio. Choose a projector that has at least 2000:1 native contrast ratio. The higher the contrast ratio, the more expensive the projector will be.
• Brightness:After paying due consideration to contrast ratio, choose a projector that has got good brightness. A minimum of 600 ANSI lumens should be the benchmark.
• Aspect ratio: Since you will be using the projector for watching cinema, choose the native 16x9 aspect ratio. I will not recommend the 4:3 aspect ratio - leave that for the boardroom.
• Native resolution: This is another very important factor. If you can afford it, absolutely aim for full-HD 1080p (1980x1080) projector. Otherwise you can settle for near-HD or 720p (1366x768) projector. But do not think anything below, e.g. VGA (640x480). It will be sheer waste of money.
• Zoom lens: The zoom lens gives the flexibility to adjust the picture size depending upon the projection distance (aka throw distance). A zoom factor or 1.2:1 lets you adjust the size by 20% only. So choose a projector that has a zoom lens of 2:1.
• Lens shift: This is a very important feature. Lens shift (horizontal or vertical) allows the projection image to be displayed correctly even if the projector is not horizontally or vertically aligned to the projection surface. So there is no need to move the projector but the lens shift does the job.
• Keystone Correction: If the projector is not pependicular to the projection surface, the projected image appears like a trapezoid instead of a rectangle. Keystone correction is a feature that lets you correct the trapezoid form to some extent. Keystone correction is always a vertical correction and digital in nature. Keep in mind that applying keystone correction results in a loss of detail and sharpness, but it can be invaluable when your projector cannot be set up perfectly square with the screen. Keystone correction is nice feature to have but not at all recommended to use - funny but true.
• Lamp Life: A projector uses a high power lamp to project the picture. This is the most imporatant component of the projector. Choose a projector with long lamp life like 3000 hrs. or so. 3000 hours is a really long time. If you watch your projector daily for 3 hours, you will 1000 days or nearly 2.75 years. And this is virtually not possible. You are more likely to turn on the projector for no more than 8 hours per week.
• Fan Noise: A projector has a built-in fan that cools the lamp. High fan noise will be a great irritant especially because, the projector is most likely to be near your sitting position. You will not like any (loud) humming sound to disturb your dialogues. Hence choose a projector with low fan noise.

Caring about the Projector
The projector is a very costly and delicate instrument. You must take extra care to protect it. Here are some suggestions:

• Avoid moving the unit when in operation.
• Dust it off often.
• The projector has a fan filter. Clean it every six months.
• If ceiling mounted, see that you can access it for cleaning.
• When not in use over long period of time, keep it covered to protect it from dust.
• The projector must never be switched off directly after use. Put it on stand-by. The fan will keep running for another five minutes at high speed to cool off the lamp.
• If your home has irratic power supply, use an online UPS for power (the kind of UPS that is used for a computer). The UPS rating should match the power supply. Most home projectors are rated from 200W to 400W. So a 500VA UPS should be sufficient.

Projection Screen
The projector must project an image somewhere. A white wall will work but a wall has many disadvantages. First the surface may not be perfectly smooth. And then the white paint may be dull or too reflective. You may even see the projection lamp. But special paints are available that can be applied to the wall. Use a specialist to do the wall. The speciallist will be able to make the wall perfectly smooth and spray paint the wall.

A safer bet will be to buy a projection screen. The projection screen is specially coated with a paint that adds to the gain of the projected light - usually by 10%. Screens will be lot less expensive. But simple pull down screens are prone to malfunction such as gentle wrapping or moving by force of the wind (for a ceiling fan, for instance). Tensioned screens are also available but much more expensive.
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A sample of the projected picture:



from the movie Body of Lies
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Final word: No amount of text will do justice here. But these are my experiences anyway. Visit Popular Home Theater Projectors for some excellent reviews.

And this concludes my HT series of articles.

thank you just4kix for these articles,it sure did get me interested in all these options which i would have never thought of,now i know what all stuff are available OUT THERE.

I forgot to add some points to the article above. Added them now.