Act II: The Projector
This is where we get into the heart of home theatre. The projector is a very different animal from its cousins the big screen TVs. A projector set up creates a much more genuine theatre feel and is the way most movies were meant to be enjoyed. Understanding the design factors and the advantages and disadvantages of certain models and how they apply to your situation is unfortunately a bit more complex than buying a TV. Also we'll examine the least discussed and understood, yet ever so vital 'liver' of home theatres; the projector screen.
*Projectors come in two main flavors; 1. DLP and 2. LCD. Each come in a variety of resolutions, brightness, and single and triple image processor setups. DLP uses a bulb shinning through a spinning color wheel then onto a chip made up of tiny mirrors which move according the the image its trying to portray. An LCD projector is not very different than your flat screen computer monitor. A light shines through a thin crystal panel that adjusts the color of the grid system according to the image as needed. I won't go much into the history or technical nuts and bolts but give some more insight as the market is at this moment (Spring 2008). DLP usually has the contrast advantage, or difference between the projectors brightest white and darkest black. (You'll see this listed as a ratio of something like 2500:1) Because the DLP mirrors are either reflecting or not, its easy to switch between full brightness and 'off'. Because LCDs have to try and block that very bright and hot bulb from shinning through the very thin film its harder to completely block it. A lot of people will be heard saying that DLP projectors have better black levels than their LCD brothers. LCD technology is more established and traditionally DLP with their color wheel, has struggled a little bit with color accurateness. The newest and more expensive models from either side of the camp have better technology to deal with these issues. There used to be a big price difference but as it stands right now they are pretty close (excluding the highest end triple DLP 1080p projectors which costs more than you would like to know).
*Moving along to resolution. This will determine the price range faster than any other spec. Since this is all for the home theatre application we will leave the 4:3 full screen (think old square TV) resolution units out of this, and focus on 16:9 widescreen resolutions. With HD on the move, the primary resolutions are as follows: 480p, 720p, 1080i, and 1080p (also referred to as full HD). ***mind your P's and I's: p= progressive scan, means that the horizontal resolution is , for all intents and purposes, doubled compared to the i which means interlaced.*** 480p is 720x480 and the resolution of the majority of regular DVD movies. 720p is 1280x720 and 1080p is 1920x1080 (1080i is pretty much a worthless resolution since due to the interlacing of the horizontal resolution it is no better than 720p). So its actually pretty simple the bigger the number of pixels or dots the better the resolution and therefor a better picture, all else being equal.
*Brightness, briefly discussed in part 1 of this post, is also very important. The brighter the projector the more flexible it is with the lighting conditions. A dim projector requires you to black out the whole room while a very bright projector can be used in a variety of light conditions.
*Bulbs. A big difference than most display types is that projector bulbs are like most any other light bulb, they need to be replaced. Most last between 2,000 - 5,000 hours and cost $300 - $400. You have to keep that cost in mind when buying one. Also check with the company you're purchasing your unit from, most have 1-4 yr service plans that will replace the bulb 1-2 times during that period, saving you hundreds of dollars.
*Installation, another big consideration is whether or not the projector you desire will work in your desired location. Check with the manufacturer or use a online projector calculator.
*-*Ok so lets get down to a few other details people will come across that I think need a little more attention. You need to realize that projectors do not have TV tuners built in. As long as you are using satellite or the equivalent you're ok. Another tid bit is the cost. People assume that because its not a TV it should be cheaper, but lets take a glance at that. These home theatre units usually have complex video processing brains to compensate for a myriad of resolutions and fast moving video that they have to deal with. Projectors are also extremely PC friendly, making it easy to hook up your laptop or home theatre PC. Finally the resolutions of the main LCD or DLP image processors are quite amazing. Lets simplify things for our mathematical comparisons. Lets say that a DLP mirror chip is 1 square inch. So a 1080p of 1920x1080 pixels equals 2,073,600 dots per square inch! Now a 50" 1080p plasma uses the same number of pixels or cells with just over 1,000 square inches dividing 2,073,600 pixels by that is 'only' a hair under 2,000 pixels per square inch. So as you can see by our very simplified mathematics we're talking about some serious hardware.
*Onto the the screen. This ultimately determines the size of your image, and like the rest of using a projector isn't as simple as you might think. The screens use different materials and can be portable and mounted on an easel, permanently exposed, manual pull downs, and automatic as your projector either turns on or off. The biggest misunderstanding is a term called 'gain'.
*Gain - a number system used to measure the reflectiveness of the material of the screen. A gain of 1.0 is considered the base or neutral gain amount. Think of it as a plain white sheet of paper. A gain of 0 is like the black hole of your dryer that eats socks and a gain of 2.0+ is like the reflective lettering used on a street sign. Low gain screens will require a brighter projector but usually help balance extreme color contrasts like a movie scene with fluffy white clouds on the top and a dark forest in view below. A screen with high gain helps with projectors with lower native contrasts ratios and help compensate for a dimmer unit. They have another disadvantage if they go too high, and that's called hot spotting. Meaning they are brighter when viewed at the same angle as the projector than view that are more extreme, low and neutral gain screens help even the image at all angles. Most screens fall between .8 and 1.2 gain and are great for most applications.
*So for my setup I ended up going with the Mistubishi HC1500 DLP 720p projector. It combines a lot of great fetures at a great price. I mainly used two online resources to come to the conclusion in purchasing the unit. Projector Central and Projector People
Both sites are great, Projector Central is more like a projector magazine while Projector People is a fantastic online store.
The Hc1500 in its natural habitat (I haven't yet hid the cables)*HC1500 specs:
Resolution:WXGA-H (1280 x 720)
Display Type:DLP®; 0.62" 1-Chip DMD, 12deg. LVDS DarkChip2™ with DDP3020 Brilliant Color and 7-segment (RGBWRGB) color wheel.
Brightness:1600 lumens
Contrast:2500:1
Weight:6.5 lbs.
Warranty:1 year(s)
Lamp Life: 2000 - 3000 hours
*Optoma Panoview Grey Wolf 92" Screen
92" diagonal screen with 16:9 aspect ratio
Gain: 1.8 screen gain
Material: High-contrast, gray-base with pearl glass-beaded screen enhances black levels and shadow details
Dimensions: Height 87" Width 100" Depth 4" Weight 26 lbs.
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