I better start off with a basic definition as to the difference between 720p and 1080p equipment (whether projectors, plasma TV's, LCDTV's etc.)
About a decade ago, the HDTV standard was set by the ITU standards folks (engineering types). They defined two different resolutions for HDTV (High Definition TV), 720 resolution (1280x720) and 1080 (1920x1080). Now, there are various ways to deal with each, such as 1080i, 1080p, and so on, but not in this article. The fundamental difference between 720p and 1080p is the number of pixels for displaying information. You can do the math. 1080 has 2.25 times as many pixels in use. That means, for any size display, there are far more and they are much smaller (and therefore less likely to be visible), creating a smoother, more detailed image to enjoy!
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If you have more money than you know what to do with, and if a 1080p projector works for your room and the types of content you watch, figure out the best one for you, and go get yourself one. Like any other technology, 1080p home theater projectors will get better and less expensive over time, so eventually, you'll buy a better one for less. Meantime you can afford a 1080p, and you'll see a difference, so why not.
If your home theater is going to look something like this, the difference in total cost between 720p and 1080p is too small to worry about. Go for it (1080p)!
Also, for those of you planning (or already having) a dedicated home theater where you will invest many thousands in furniture, thousands more, each, for wiring, painting, installation, and audio equipment, and probably thousands more for this and that (popcorn machines, poster artwork, sconces for the walls), it certainly would seem questionable not to buy a 1080p projector, when the difference between a 720p projector and a 1080p projector, is maybe only 10-30% of the cost of the entire theater.
For the rest of us, with somewhat limited funds, it's a tougher call, and that's what this article is about, helping you decide the best plan for you.
Life was simple until a few months ago. Entry level projectors were sub-HDTV resolution models, primarily with 480p resolution (854x480), the same resolution as standard DVDs. There are also still one or two 1024x576 resolution projectors out there, like InFocus's IN74EX. I should note that a year ago, you could spend $4000-$6000 or even more, online, for one of the better 720p projectors. And you could spend $15,000 on a high end single chip DLP like the Marantz VP-12S4. (Three chip DLP projectors are in a whole different class, so we'll skip them for now, suffice to say that they started at $15,000 a year ago).
Today, 480p projectors are now selling for well below $1000. In fact, some can be found for less than $500. 480p projectors, however all suffer one critical problem. Pixel visibility (and therefore Screen Door Effect), is significant. You can make out the pixel structure at any normal seating distance. True, LCD 480p home theater projectors still have more visible pixels than their DLP counterparts, but in all cases, you can see the pixels, say at 15 feet from a 100" diagonal 16:9 screen.
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So, until last fall, the choices were - 480p (and 576p) as a true "entry level" projector, and everything else, which were 720p resolution (the lower of the two HDTV resolutions).
Shown here, the 720p resolution, Panasonic PT-AX100U, considered by most, to be the best selling home theater projector in the US. LCD based, it has excellent placement flexibility, and is also the brightest of the home theater projectors
But, this past September ('06), the first batch of affordable 1080p projectors, currently with selling prices from about $3500 to $8000, (if you call $8000 that affordable), started hitting the market. I currently count at least 7 models that fit that description.
And, this raises the question for many - can I be happy with a 720p projector, or do I need to spend a few thousand dollars more for a true 1080p home theater projector.
1080p became the rallying cry of the RPTV's (Rear Projection TV) and LCDTV's just over a year ago. Manufacturers wanted to sell the 1080p concept to consumers to keep the average price of a HD TV from dropping, thus convincing more people to pony up for the 1080p models.
Personally, my feelings is that for RPTVs (aka big screen TV), in most homes, the move from 720p to 1080p is marginal, and likely invisible to most people buying sets under 50" diagonal. (Consider - there are no 1080p 50" plasma TV's, just 720p and lower resolution).
The big questions start off with: Will I see the difference?
First of all, for those big screen TV's and LCD TV's the answer, first and foremost, is: Maybe! It depends on how close you are going to sit, and the size of your display.
Put simply - if you are going to sit 12-15 feet from a 40" or 50" LCDTV, you just are too, too far away to distinguish between 720p and 1080p resolution. Hey, at 15 feet, even a 27" conventional TV looks razor sharp. You will need binoculars to tell the difference in resolution. That should give you an idea of where I'm going with this:
Home Theater Projectors offer you by far, the largest images available in your home. They are designed, by concept, to be large and to immerse you in the content.
As a result, it is relatively easy to spot the extra detail and sharpness of a 1080p model projector, compared to a similar 720p model.
In other words - if there is one market where 1080p has a really significant advantage, it is with home theater projectors.
Today's 720p home theater projectors start at less than $1000, while, as I mentioned above, the least expensive of the 1st generation of "affordable" 1080p projectors is just under $4000.
What are the critical deciding factors for each of us, in deciding, among these choices:
What other elements need to be considered, besides resolution? For you to make an intelligent choice, there are a number of non-resolution issues. For example, most 1080p projectors are not as bright as their 720p equivalents.
Here are the factors we will consider:
I'm going to start with those true entry level projectors - 480p models, like InFocus's IN72, BenQ's W100, Optoma's older H27 and H31's, not to mention most of the all-in-one projectors.
When dealing with standard DVD, which is 480p native resolution, these lowest resoluton projectors do not need to rescale the image. Ideally, therefore they have one pixel in the display for each pixel of information. The end result is no distortion from sampling and rescaling.
That, however is not enough to give them a real advantage. And unfortunately, 480p projectors have seriously visible pixel structures. LCD are worse than DLP, but either way, at any normal seating distance, the pixels are definitely visible in most content. So, the instant answer here, is that 1080p projector have a huge advantage in projected image quality.
Move to the more serious comparison of 720p projectors to 1080p projectors, and things get just a touch murkier. However, as a group, I cannot think of any good reason why a 1080p projector would not produce at least as good an image as a 720p projector on either standard TV, or standard DVD.
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When rescaling DVD from 480 to 720p or to 1080p there should be virtually no deterioration in image quality. (It's easier to take a low res signal and stretch it to work with a high resolution device, than the other way around). As a result - all else being equal, the 1080p projectors have the advantage of less visible (or invisible) pixel structures. 720p projectors with 480 source material are more likely, therefore to generate a screen door effect.
Probably the only arena where the 720p projector would likely have an advantage is on those HDTV channels that are broadcast in 720p, not 1080i. Why, it comes back to no rescaling of the image 720p in - 720p out! Conversely though, 1080i HDTV would produce a sharper, cleaner image on a 1080p projector.
Bottom line - there will be variations (some significant), between different 1080p projectors in how they work with lower resolution sources. As a result, it is possible that a 720p projector may actually do a better job on a standard DVD or conventional TV, and also with a 720p HDTV signal, but only if the 1080p projector in question is not processing the lower resolution sources very well. In viewing both conventional TV and standard DVD's, I do see some variation from one 1080p projector to another. However, the same is true of 720p projectors. So, unless you have a 1080p model that is particularly poor and a 720p projector that is particularly good at lower resolution, the 1080p should have a definitive advantage.
The real issue is that standard TV will almost always look lousy. Projectors project too large an image to allow standard TV to look like anything resembling good (although there are some impressive outboard processors for a couple thousand $$).
Basically - garbage in - garbage out. I personally believe most of us should focus on how the projectors handle quality content, and not worry about whether a projector on standard TV does lousy, or lousy+. Remember - more and more content is coming in hi def.
Thus, no reason not to buy 1080p projectors - just because you watch a lot of poor quality programming. More HD channels coming, more hi def DVDs.... Why worry?