Editor's Note: This article was written in 2009. Many technological changes have occurred since 2009. We plan to update this article as time allows.(5/25/17)

Introduction

If you are new to the world of digital projectors, you won't have to shop around long before discovering that the terms LCD and DLP refer to two different kinds of projectors. They are in fact two different kinds of microdisplay imaging technology. You might not even know what LCD and DLP are before asking the obvious question "which one is better?"

The answer is simple--neither one is better than the other. They both have advantages over the other, and they both have limitations. Both technologies are much better than they used to be. The purpose of this article is to discuss how they differ today, so you can determine whether the imaging technology itself is a relevant factor in your choice of a projector.

It is important to note there is a third significant light engine technology called LCoS (liquid crystal on silicon). It is developed and marketed by several vendors, most notably Canon, JVC, and Sony. Many excellent projectors have been made with LCoS technology, including several outstanding home theater projectors that can, in the opinion of many observers, surpass the value proposition of both LCD and DLP offerings. The discussion of LCoS technology is beyond the scope of this article, and will be addressed separately in an upcoming article.

Is it 3LCD or LCD?

You may have already seen the term 3LCD on websites and in projector literature and press releases. Several makers of LCD projectors have adopted 3LCD as a marketing brand name. It is intended to distinguish the specific implementation of LCD technology found in digital projectors from the more common direct view LCD displays found in a wide variety of consumer products. In LCD projectors there are always three LCD panels, and they are always light transmissive devices rather than reflective or direct view displays. Within the projector industry, there is no technical difference between 3LCD and LCD, and the terms can be used interchangeably.

Which Technology Leads the Market?

Well, the answer to this question depends on your definition of the word "lead." As of this writing, DLP technology has a significant lead in terms of the number of models currently in production. As of this date, July 28, 2009, our database lists 704 different DLP-based models in production, as compared to 430 LCD models. Thus, DLP holds a commanding lead in the number and variety of models being produced.

However, this is not the whole story. Many of the best selling projectors these days are LCD models. As an example, at the moment, six of the Top 10 Most Popular 1080p home theater projectors on this site are LCD's, two are DLP and two are LCoS. In fact, despite the clear advantage DLP has in the number of models in production, Pacific Media Associates reports that LCD projectors held a 51% market share by unit volume in 2008. Clearly both technologies have a huge market presence, and neither one is about to emerge as the dominant player.

The Technical Differences between 3LCD and DLP

LCD (liquid crystal display) projectors contain three separate LCD glass panels, one each for the red, green, and blue components of the video signal. Each LCD panel contains thousands (or millions) of liquid crystals that can be aligned in either open, closed, or partially closed positions to allow light to pass through. Each liquid crystal behaves in essence like a shutter or blind, and each represents a single pixel ("picture element"). As red, green, and blue light passes through the respective LCD panels, the liquid crystals open and close based on how much of each color is needed for that pixel at that moment in time. This activity modulates the light and produces the image that is projected onto the screen.

DLP ("Digital Light Processing") is a proprietary technology developed by Texas Instruments. It works quite differently than LCD. Instead of having glass panels through which light is passed, the DLP chip is a reflective surface made up of thousands (or millions) of tiny mirrors. Each mirror represents a single pixel.

In a DLP projector, light from the projector's lamp is directed onto the surface of the DLP chip. The mirrors tilt back and forth, directing light either into the lens path to turn the pixel on, or away from the lens path to turn it off.

In the most expensive DLP projectors, there are three separate DLP chips, one each for the red, green, and blue channels. However, in most DLP projectors under $10,000 there is only one chip. To define color, a color wheel is used that contains (at minimum) a red, green, and blue filter. This wheel spins in the light path between the lamp and the DLP chip and alternates the color of the light hitting the chip from red to green to blue. The mirrors tilt away from or into the lens path based upon how much of each color is required for each pixel at any given moment in time. This activity modulates the light and produces the image that is projected onto the screen.

(Note: In addition to red, green, and blue filters, most color wheels contain other segments as well. A "white" or clear filter used to boost brightness is common in business/commercial projectors, and many color wheels have filters for colors other than the primaries, such as dark green, cyan, magenta, or yellow.)

The Advantages of DLP

We will look at the advantages and limitations of both DLP and LCD in turn. The most important advantages of DLP technology include the following:

Sealed imaging chip. Most DLP projectors have sealed DLP chips that eliminate the possibility of a dust particle alighting on the imaging plane, which could create a dust spot on the projected image. LCD projectors do not have sealed panels, and the possibility of getting a dust spot exists. This is especially true when air filters are not cleaned periodically as per operator manual instructions.

Filter-free. DLP projectors that have sealed DLP chips can operate without air filters. Thus maintenance is reduced since there is no need to periodically clean or replace filters. Some vendors represent their DLP products as maintenance free, other than the occasional lamp change and dusting of the case and lens. Others don't go quite that far, and recommend a periodic vacuuming of the air vents to limit the amount of dust getting into the unit. The vast majority of DLP projectors on the market do not have air filters, but some of the most expensive high performance 3-chip DLP models do, as do a few earlier generation DLP models that may still be in use.

Whether filter-free design is a true advantage to the user is a matter of competitive debate and controversy. In most DLP projectors, components other than the imaging chip itself are not sealed and can be adversely affected by a build-up of dust. In particular, dust on the color wheel may affect color and image quality. Dust particles can burn or melt when coming into contact with the lamp surface, thereby accelerating the degradation of lumen output over the life of the lamp. The degree to which a filter-free projector might be adversely affected depends on how much dust there is in the operating environment. Texas Instruments maintains that the amount of dust found in a normal room environment will not adversely affect the operation of a filter-free projector. Those who advocate the use of filters maintain that air filters will prevent an accelerated degradation of the lamp's lumen output, even in normal room conditions.

Recognizing dust as a potential problem, Mitsubishi has taken extra steps to combat dust contamination in their latest filter-free DLP projectors, the XD3200 and WD3300. They have sealed the color wheel to prevent dust from reaching it. They have also made design improvements to the light pipe and airflow channels which reduce the amount of dust that can reach the lamp. These changes are intended to help maintain the lamp's lumen output potential over its lifespan.

Those who advocate using air filters on projectors maintain that dust is never good inside a projector, and that the user is better off with a filtered design that prevents dust from entering the projector to begin with. All LCD projectors use air filters, as do some of the higher end 3-chip DLP models from vendors such as Runco and Digital Projection.

Those who support filter-free designs point out that many users of filtered projectors do not follow recommendations for cleaning or replacing air filters. If an air filter gets clogged over time, it can inhibit airflow, increase internal operating temperatures, and adversely affect the life of the LCD panels.

No convergence problems. All projectors using three imaging devices, whether they are LCD, DLP, or LCoS, must have all three devices aligned perfectly so that the red, green, and blue information for each pixel is in convergence. Over time, these three device systems can slip out of alignment. On occasion they can come out of the box, brand new, with slight convergence errors. Convergence errors can soften the projector's image and create color artifacts where there shouldn't be any.

The single-chip DLP design has a unique advantage over all three-chip or three-panel systems: since there is only one imaging chip, convergence problems don't exist. There is simply nothing to go out of alignment.

Contrast advantages. Most business class DLP projectors (those intended for portable presentation or conference room use) have much higher Full On/Off contrast ratings than comparably priced LCD models. ANSI contrast figures are rarely published in the projector industry, but our measurements indicate DLP projectors usually have an edge over the LCD competition in ANSI contrast as well. However, with the introduction of inorganic LCD panels that are now used in most LCD 1080p home theater products, DLP's traditional advantage in contrast within the home theater market niche has been neutralized to a large extent.

No image persistence. If one displays a static image for an extended period of time, an LCD projector with organic LCD panels may have a tendency to retain a subtle ghost of that image even after the subject matter is switched to another image. This does not occur on a DLP projector. Nor does it occur on LCD projectors that use inorganic panels.

Some of the advertising hyperbole has blown the seriousness of this issue out of proportion. Anti-LCD ads have claimed that LCD projectors are subject to "burn-in." Strictly speaking, this is not really true. Burn-in, in traditional usage, refers to permanent damage that can be suffered by CRT or plasma phosphor-based displays. Once a static image has been etched into a phosphor display through long term exposure, it cannot be removed. This is a different phenomenon than we see on LCDs. On organic LCD displays, when image persistence occurs, it is temporary and can normally be erased by displaying a white screen for a period of time.

Nevertheless, the point is that image persistence does not occur on either DLP projectors or inorganic LCD projectors. So on these products there is never any need to take steps to erase a persisting image.

No degradation of image quality over time. There is usually no degradation of image quality on DLP projectors when used over long periods of time, other than that which might result from excessive internal dust build-up. But in any event, the DLP chips themselves will not degrade. Conversely, LCD panels and polarizers can degrade with time, causing color shifts, unevenness of illumination, and reduction of contrast. The degree to which LCD degradation is a problem on current products is somewhat of a mystery since those who know the most about it (the LCD manufacturers) don't discuss it publicly. This issue will be discussed further below.

Somewhat less pixelation/screendoor effect on low resolution products. One of the historical advantages of DLP over LCD has been a reduced level of pixelation in the image. Pixels tend to have sharper definition on an LCD projector, and this can produce a more visible pixel structure in the image. This is often called the screendoor effect, since the picture on low resolution projectors can look like it is being viewed through a screendoor.

However, the differences between LCD and DLP in this regard are not as great as they used to be for two reasons. First, LCD makers have achieved smaller interpixel gaps, making the screendoor effect much less visible. Second, the average native resolution of projectors being sold today has increased dramatically over what it was several years ago. With increases in resolution come smaller pixels and a less noticeable pixelation across the board. Nevertheless, on low resolution products like SVGA and even standard XGA, DLP projectors still have an advantage in manifesting somewhat less visible pixel structure than LCD projectors. (Note: There is a disadvantage to having less distinct pixel structure, which is reduced image sharpness. We will discuss this further below.)

DLP leads in miniaturization. The single-chip light engine affords the opportunity for extreme miniaturization that LCD cannot quite match. At the moment there are 15 DLP projectors on the market that weigh less than 3 lbs and put out more than 1000 lumens. By comparison, the lightest 3LCD projector on the market weighs 3.5 lbs and most are 4 lbs or more.

Weaknesses and limitations of DLP

Color wheels can produce rainbow artifacts. The problem people point to most frequently as a weakness in DLP is its tendency to produce "rainbow artifacts." Rainbow artifacts (sometimes referred to as color separation artifacts) are momentary flashes of banded color that look like rainbows. They occur at random, and they only last for an instant. But for people who are sensitive to them, they can be quite distracting. If you are engrossed in a film or video, they can take you entirely out of the video experience.

Rainbow artifacts are a problem only on single-chip DLP products, and for the most part, only those using slower speed color wheels. They can also occur on LED-based models due to the sequential strobing of red, green, and blue LEDs. Typically the problem manifests itself when the viewer is watching movies or video. When viewing static images such as presentation charts or photographs, people generally do not experience the problem.

The rainbows occur because of the sequential color updating from the wheel or LED. As the color wheel spins or the LEDs change, the image on the screen is either red, green, or blue at any given instant in time. The technology relies upon your eyes not being able to detect the changes from one to the other. However, when your eye moves rapidly in response to some movement in the picture, you can get a red, green, and blue update on three different points on your retina, thus producing the impression of a rainbow. Not everyone perceives rainbows the same way. Many people have less sensitive eyes and cannot detect rainbow artifacts at all. Others see them quite readily. There is no way to know whether you are among those who can or cannot see them except by watching a DLP projector yourself.

Since LCD projectors and 3-chip DLP projectors always deliver a constant red, green, and blue image simultaneously, they do not create rainbow artifacts.

On DLP projectors with color wheels, rainbow artifacts are reduced by increasing the speed of the wheel. The first generation DLP projectors incorporated a color wheel that rotated sixty times per second, or 3600 RPM. With one red, green, and blue filter in the color wheel, updates on each color happened 60 times per second. This rotation speed in the first generation products was known as a "1x" rotation speed. In second-generation DLP products, the color wheel rotation speed was doubled to 2x, or 7200 RPM. The doubling of the color refresh rate reduced the time between color updates, and so reduced the visibility of rainbow artifacts for most people. But a 2x rotation speed was still not fast enough for products to be used in home theater and video applications.

Today, some DLP projectors being built for the home theater market use a color wheel containing two sets of red, green, and blue filters. This wheel still spins at 7200 RPM, but because red, green, and blue are refreshed twice in every rotation rather than once, the industry refers to this as a 4x rotation speed. And by increasing the physical rotation speed beyond 7200 RPM, some projectors now have 5x or 6x speed wheels. For the large majority of users, the 5x and 6x speed wheels in most current home theater models have reduced rainbow artifacts in video display to the point where they are of little or no concern.

However, most DLP projectors built for commercial/presentation use still use 2x speed wheels because they are less expensive. This is perfectly fine if the presentation matter is static charts, graphics, photography, or anything that does not stimulate rapid eye movement. We do not recommend DLP projectors with 2x speed wheels to buyers for whom video display or part time home theater are important intended uses.

Color saturation/color brightness. Some DLP projectors have excellent color saturation, and some are exceptionally poor. This is related more to the vendor's implementation than anything inherent in the technology itself. Advocates of 3LCD technology have been quite vocal about the lack of color brightness on single-chip DLP products, particularly those that have white segments in the color wheel. This phenomenon is worth commenting on.

When a color wheel has a white (clear) segment, the lumen output of the projector is increased dramatically, and the ANSI lumen rating skyrockets. Most business class DLP products have white segments in the wheel to boost the all-important lumen rating. Conversely, most DLP projectors built for home theater have no white segments because they can compromise color saturation and the overall balance of the video image. Moreover, the lumen rating is not a big driving factor in the sale of home theater projectors.

When you use a light meter to measure the brightness of red, green, and blue on an LCD projector, the sum of the values usually adds up to the brightness reading you get for white. This makes sense because on an LCD projector, white is created by turning the red, green, and blue channels all fully on. But on a DLP projector, this is often not the case. Due to the presence of a white segment in the wheel, the white reading can be as much as double the sum of the brightness readings for red, green, and blue. In other words, if an LCD projector measures 2000 lumens of white light, you will also get 2000 lumens of color light out of it. If a DLP projector measures 2000 lumens of white, you might get only 1000 lumens of actual color light from it, the rest being white light.

Because of this, proponents of 3LCD technology have been lobbying for color brightness specs to be included along with ANSI lumen specs on the industry's specification sheets, and support for this has been building in the industry. In the spec wars, quite clearly this would be one metric on which LCD has a commanding advantage over DLP. Not surprisingly, Epson and Sony have already begun to publish color brightness specs on their LCD projectors to drive home the point. The color spec is always the same as the ANSI lumen rating, and the specs will read, as an example, "2600 lumens color light output, 2600 lumens white light output."

As a rule, DLP projectors with a white segment in the wheel do not look very appealing when measured for color brightness. The color reading always fall short of the white reading, and sometimes it falls short by 50% or more. This is especially true when the color wheel contains the basic red, green, blue, and white filters only. Many DLP projectors have complementary color filters such as cyan, magenta, and yellow. In this situation the color brightness measurements become more problematic. Thus we can understand why Texas Instruments and the DLP projector vendors have little interest in publishing color brightness specifications.

From a practical perspective, we have mixed feelings about all of this. Clearly, the 3LCD camp is correct that the traditional ANSI lumen spec does not tell the whole story. But neither does the color brightness spec. To be sure, the color on some DLP projectors looks dull and anemic next to some LCD models of the same lumen rating. Ironically, this can be particularly true when the "BrilliantColor" feature is enabled. Though BrilliantColor boosts the brightness of the image, it can substantially reduce color saturation in the process. It is peculiar that in order to get the richest and most saturated color from many DLP projectors, one needs to turn BrilliantColor off. (This is not universally true of all DLP projectors with BrilliantColor, since the BrilliantColor system can behave quite differently based on how it is implemented by the vendor.)

Oddly enough, on some DLP models with white segments in the wheel, even those on which color brightness falls far short of white, we see a rich, vibrant color that can easily match an LCD projector in the same price and lumen class. One reason is that the color filter configuration of the wheel has a lot to do with the end results. Another reason is that, though the DLP's color brightness may fall short of white, the effect of the DLP's inherent contrast advantage helps to compensate for it. That compensating effect cannot be quantified in a spec. Even when color brightness falls very far short, the picture sometimes does not end up looking much dimmer at all when put side by side with an LCD projector of the same white light output.

When a DLP projector's color vibrancy looks poor next to a comparably priced and spec'd LCD projector, it is due to a variety of design and product cost decisions made by the vendor, and not anything inherent to DLP technology per se. DLP can look truly spectacular or downright dismal depending on what is done with it. With so many variables in play, the specs can't tell the whole story, even if a color brightness spec were added to the mix. The publication of color brightness specs would be interesting, and would certainly draw attention to a noteworthy technical difference between LCD and DLP. But it is not conclusive information that would help an astute buyer sort out which model to buy.

Dithering artifacts. At any moment in time, each mirror position on a DLP chip is either fully on to render maximum brightness, or fully off to render black. There is no way a DLP mirror can be "partially on" to represent gray, like an LCD liquid crystal can. Therefore, the way the DLP chip renders gray is to flip the mirrors on and off very rapidly, such that they are on just enough of the time for the eye to average the "on's and off's" to a desired level of perceived brightness. This approach to rendering grays is called dithering. It works well enough for rendering gray values, but it can produce some visible instability in solid fields, mostly dark areas, referred to as dithering artifacts. It looks like digital noise, but it is a separate type of artifact caused by DLP technology itself, and not by the signal.

Dithering artifacts do not occur on LCD products because there is no dithering used to achieve varying levels of gray. The liquid crystals can be either fully open, or closed, or partially opened at intermediate positions to achieve the desired level of light transmission--again, similar in concept to shutters on a window.

Restricted compatibility with zoom lenses and lens shift. Due to the nature of DLP light engine mechanics, it is difficult for vendors to incorporate long zoom lenses or extended range lens shift features into a DLP projector. These limitations are not relevant in mobile presentation projectors since the primary design objective is small physical size, so none of them have big zooms or lens shift anyway. But in the home theater market in particular, LCD vendors have captured significant market share in part due to their ability to incorporate long 2.0x zoom lenses and extensive lens shift capability into LCD projectors. This makes it much easier for the consumer to install the projector anywhere they want, which is quite frequently on a rear shelf in the room. Due to lens restrictions on DLP projectors it is rare to be able to install a DLP model on a rear shelf.

The Advantages of 3LCD

Many of the advantages and limitations of 3LCD have already been touched on above within the context of the DLP discussion. However, there are several advantages of LCD not yet discussed, and some of the issues already noted warrant a recap and/or further expansion. The following are the key benefits of LCD technology:

Better price/performance in HT products. The primary key to the success of LCD products in the home theater market is their tremendous price advantage. In the 1080p niche in particular, LCD products deliver outstanding image quality performance for the money. Moreover, they are generally loaded with extra features that don't appear on DLP models in the same price range, if they are offered on any DLP model at all.

The price advantage of LCD over DLP is most obvious in consumer/home theater products. There is no similar disparity in pricing on commercial products built for mobile presentation and conference room use. One reason is that DLP makers can use the cheaper 2x speed wheels on most business products, whereas it is mandatory to have high speed color wheels and the faster electronics associated with them on products designed for home theater.

Higher contrast in HT products. Many LCD projectors built for home theater have achieved better overall contrast performance and deeper black levels than DLP models. This is specifically the case on LCD models using inorganic LCD panels and auto iris technology. Inorganic panels are more expensive to produce, so they are not used in cheaper, commercial grade business projectors. They achieve higher contrast due in part to the fact that the resting position of the liquid crystal is closed (i.e., black), and voltage is required to open it. This is the opposite of traditional organic LCDs wherein the resting position is open (maximum light transmission), and voltage is required to close it. The inherent contrast advantage of inorganic panels has made LCD substantially more competitive in the home theater marketplace. ANSI contrast in particular has seen significant improvement. In our measurements, LCD projectors with organic panels typically run in the range of 250:1 ANSI contrast, whereas the models with inorganic panels have been reaching performance levels of 400:1 to 450:1.

3LCD vendors have been aggressive in developing effective auto iris systems which contribute an incremental perceived contrast advantage on screen. There is no technical restriction that we know of that would prohibit DLP vendors from doing the same thing. But it would add further cost to DLP projectors that are already at an apparent cost disadvantage relative to LCD in the home theater market. There is also a perception among vendors that DLP contrast, while not leading edge, is sufficient, so enhancement via auto iris is not vital. Thus, most DLP vendors have been slow to incorporate auto iris systems on DLP projectors being marketed for home theater.

Fewer artifacts/greater image stability. As noted previously, dithering artifacts and rainbow artifacts are unique to single-chip DLP projectors. Since these artifacts do not exist on LCD products, it is not unusual to perceive a more stable video image on an LCD projector when viewed side by side with a DLP counterpart in a similar price and performance class. The LCD's video image can look cleaner and more free of noise.

Sharper image with data display. Since LCD pixel structure is more sharply defined that DLP pixel structure, it tends to render a sharper image. This is most noticeable in lower resolution business products (SVGA and XGA), and specifically with data display. It is in these resolutions that LCD's screendoor effect is somewhat more visible in a video image, but the advantage is that the sharper pixel definition can produce a sharper display of data. By comparison, a DLP projector in SVGA and XGA resolution can look a bit soft when displaying data images.

On higher resolution products the difference in apparent sharpness is minimal, and it is a non-issue with video display on 1080p products. Both technologies can produce very sharp images in 1080p, and any perceived differences in sharpness typically have to do with factors unrelated to the display technology, such as lens quality and video processing.

Greater installation flexibility in HT products. LCD projectors built for home theater often feature 2.0x zoom lenses and extensive vertical and horizontal lens shift. This makes them easy to install just about anywhere. By comparison, DLP projectors usually have short zooms with little or no lens shift. Fixed throw angles limit the projection geometry, and often dictate where a DLP projector must be placed in order to accommodate a given screen size and location.

For the DIY home theater enthusiast on a budget, the lens flexibility of LCD models has great appeal. For the fact is, most DLP projectors need to be ceiling mounted, and most LCD projectors don't. Thus they save the extra cost of a ceiling mount and long run video cables. They also eliminate the prospect of having to run cables through walls and ceiling, or living with an unsightly track of cables across the ceiling.

Better light efficiency, less power usage. LCD technology is inherently more light efficient. For the most part LCD projectors use lower wattage lamps to produce the same image brightness that you'd get from DLP. This is most noticeable when comparing LCD projectors to DLP projectors that have no white segment in the color wheel. As an example, compare two currently popular 1080p home theater projectors--the Panasonic AE3000 LCD projector uses a 165-watt lamp to produce 1600 ANSI lumens. Meanwhile, the Sharp Z15000 DLP projector needs a 250-watt lamp to get the same 1600 lumens. That can make a noticeable difference in power consumption. It can also make a difference in the amount of heat being generated by the projector's exhaust in the viewing room.

Weaknesses and Limitations of LCD

Unknown lifespan of LCD panels. Given enough prolonged exposure to high intensity UV light and extreme heat, the organic compounds used in most LCD panels are expected to degrade over long periods of time. This degradation can lead to a discoloration of the image and a reduction in contrast. The only way to fix it is to replace the damaged LCD panel, which is typically a cost-prohibitive proposition. You are normally better off buying a new projector.

The big question of course is how long the panels will last. There is no good data on this subject that has been compiled by an independent lab and published for general consumption. LCD vendors do not typically acknowledge LCD degradation can occur, so they don't make any representations about expected life. In general, most LCD vendors maintain that to the degree LCD panels might be subject to eventual degradation, it will be beyond the practical life of the product.

One trusted and very experienced industry source who develops products using both LCD and DLP technology believes that LCD panels have a lifespan in the range of 4,000 to 10,000 hours, with the lifespan depending on how bright the projector is--the brightest LCD light cannons will produce the most stress on the panels resulting in quicker degradation. Low brightness models such as those made for home theater will produce the least stress, and are expected to last longer.

Texas Instruments has performed several tests on LCD lifespan over the past seven years. Based on these tests, they believe that LCD panels will degrade faster than the LCD vendors are willing to admit, and certainly more quickly than the 4000 hours just quoted. The 3LCD camp's response is that TI's tests have been performed by running LCD projectors continuously 24 hours a day, 7 days a week, for several months straight. According to 3LCD and Epson, since the projectors used in TI's lab tests were never designed for a continuous operation high-stress duty cycle, the results are not indicative of what the typical user would experience.

The introduction of inorganic LCD panels is an important new development that is germane to this issue. Inorganic LCD panels, in theory, should not be subject to the same degradation patterns as organic LCDs, simply because the organic compounds that fail under intense heat and UV light are not present in inorganic LCDs. However, the LCD camp will not confirm or deny any anticipated differences in panel life because as a matter of policy they do not discuss the issue at all. Texas Instruments has not commented on the expected lifespan of inorganic LCDs either.

Lower contrast ratings in business products. Most commercial and education LCD projectors are made with the relatively inexpensive organic LCDs and no auto-iris. Contrast ratings on these models typically run in the 400:1 to 700:1 range. Meanwhile, DLP projectors in the same resolution, lumen, and price class can often be rated at 2000:1 or higher.

In reality, this constitutes more of a marketing disadvantage than a technical one. In most business/commercial and classroom settings, projection display is done with room lights on. With moderate ambient light--enough for children in a classroom to take notes for example--a projector's contrast rating is largely irrelevant. Actual contrast on screen with moderate ambient light is typically in the range of 50:1 regardless of the theoretical contrast potential of the projector. But for buyers who are not aware of the huge impact of ambient light on contrast ratios, the apparent advantage of DLP over LCD in contrast ratings can appear to be more significant than it really is.

Susceptible to dust spots. Since LCD light engines are not sealed, it is possible for dust particles to alight on the LCD panels, thereby creating a dull, indistinct spot on the projected image. This usually causes little distraction when displaying static images such as data or photographs. But in full motion video, seeing a stationary element in a moving picture can be extremely distracting.

When dust lands on an LCD in the red or blue channel it is rarely visible enough to create a distraction. But when it occurs in the green channel it can become quite visible. Some vendors have provided methods by which the user can remove the dust without having to send the unit in for cleaning. Sanyo's home theater models come with a hand pump that will blow a jet of air across the panels, but since we've never seen a dust spot on a Sanyo projector, we've never been able to test the device. Other than this sort of solution, packing the projector up and sending it to a maintenance depot for cleaning is the method of last resort for getting the projector back into serviceable shape.

LCD makers claim that today's air filter systems are superior than those of the past, and that dust contamination is highly unusual if the filters are cleaned and replaced as per normal maintenance instructions. Most LCD vendors cover dust removal under warranty, which is a good reason to buy LCD projectors with extended warranties.

When we review projectors, we have no way to assess the actual risk to the user of dust contamination on any particular model. We can say that it is rare for us to notice dust spots on LCD projectors that we get in for review, or on units that we keep in operation for ongoing reference purposes. However, it is easy for users to forget to clean filters since under normal usage vendors recommend this be done every two months or so. When filters are left unattended, the user increases the risk that dust will eventually find its way into the projector.

Conclusion

The fight for market share between 3LCD and DLP continues at a fevered pitch. It is a fascinating thing to watch as vendors of both technologies continue to innovate to stay a step ahead of the competition. Picture quality in digital projectors has improved dramatically over the past decade with significant increases in contrast, resolution, and color performance. Prices have dropped like a rock, and high quality projection systems that once were within financial reach of wealthy consumers or businesses who really needed them, are now within the budgets of mass consumers. Thus the consumer is the ultimate beneficiary of the intense competitive struggle between the DLP and 3LCD technologies.

As we've tried to make clear in this article, both DLP and 3LCD have key advantages over the other. They also both have limitations that the buyer should be aware of. But in the end, we see better image quality performance today from both LCD and DLP than we've ever seen in the past. And it just keeps getting better.

 
Comments (65) Post a Comment
Michael Belsh Posted Jul 28, 2009 8:37 PM PST
A good read indeed! Thanks so much for giving the information you did.
Rick Posted Jul 29, 2009 6:59 AM PST
Based on my experience with LCD projectors, my rule of thumb for organic LCD panel degradation is to assume that the projector will be unusable by the time you finish the second bulb. So if the bulb is rated at 3000 hours, I would assume a useful life of the projector at no more than 6000 hours. If you use such an organic LCD projector as a TV replacement you will likely have to replace it every few years.
Richard Posted Jul 29, 2009 7:29 AM PST
Owner of 14 projectors I have used both LCD and DLP projectors in a 24 hour a day operation with static images on the screen for the most part. I have found DLP projectors out perform LCD in many areas. I have middle of the road $5k DLP projectors and one high end >$12k all of which have lasted years longer than my LCD projectors all of which were >$10k. I actually replaced LCD panels regularly in one manufacturers and the burn out was quick. The other projector was cost prohibitive to replace. I will go with DLP unless the unit is not used much.
mikeb Posted Jul 29, 2009 8:47 AM PST
If an LCD panel can produce for example 2000 Lumens at white (all 3 panels on full), then how can it produce 2000 Color Lumens? Like if it's a Red color being displayed, it wouldn' t use all 3 panels on full thus the Lumen output would have to be greatly reduced. It would be primarily the red panel on and the other would be off or greatly reduced.
Thomas Posted Jul 29, 2009 9:52 AM PST
Is there any anecdotal evidence that inorganic LCD panels do last longer? I'd be particularly interested in hearing from someone like Richard who appears to really put projectors through their paces.

I have to wonder if the fact that TI has not published the results of a study on inorganic LCD means that the panel life is long enough to be a non-issue. This isn't evidence in itself, but it is one plausible explanation.

I've had a DLP projector in the past and was relatively happy with it. I've been considering LCD, mainly because of the placement flexibility of zoom & lens shift, but things like dust blobs and panel life have made it difficult to pull the trigger on those purchases.

It would have been interesting to hear details on why DLP cannot have the zoom and lens shift flexibility of LCD. I've heard the lens shift is because of the issue of bouncing of the light off the DLP chip through the color wheel and then through the lens so that in order to shift the lens you'd have to move the entire light path. I've not heard any reasoning for the lack of zoom found on DLP.

Wish the LCoS comparison had been included with this article, but will wait patiently for it and hopefully it will compare and contrast against DLP/LCD and not simply be a stand alone tech summary.
eumigfan Posted Jul 29, 2009 12:44 PM PST
What a great article! Very fair and balanced- unlike some news channels! I have had a Panasonic AE700 LCD projector for 5 years now and have had no dust blobs or PQ degradation whatosever. I am still using the original bulb, and the picture is still stunning. I love the 2X zoom lens and wide-range lens shift which lets me mount the projector out of sight on a rear shelf. I just would not take the risk of seeing the DLP artifacts, so my next projector will definately be 3LCD.
Pat Posted Jul 30, 2009 11:55 AM PST
This is the first I've heard that dust deposits lead to the lamp becoming dim. I find this a little hard to believe. If it were true then LCD projectors with dust filters would have substantially longer bulb lives than filterless DLP projectors. I don't think this is true.

Also I used to periodically clean inside my first projector an InFocus X-1. The color wheel got grayed out by deposits not the bulb. Wiping off the color wheel greatly improved the image brightness. I believe that this deposit was from plastic volatiles that had settled on the relatively cool color wheel. I don't think it was melted dust. Am I wrong?

Lastly, why are there no single chip LCoS projectors? LCoS is refelective like DLP? It should I would have thought been a good candidate for for a one chip/color wheel design. Maybe its the speed question?

What does a DLP chip cost?
Norman T Posted Jul 30, 2009 12:03 PM PST
Strangely enough my experiences with LCD life issues agree with both eumigfan and Rick above.

When the Panasonic PT-AE700U 3LCD projector was the hot new player on the price/performance curve I installed two of them. One was in a friend’s dedicated home theater and the second was in my family’s home theater/living room.

The AE700U in the dedicated home theater still looks great after almost 5 years of service.

The AE700U in my home developed severe blue discoloration in the lower left side of the image due to the organic LCD panels. One can find many users so afflicted on the forums. Of course this did not come up when the AE700 was the hot new piece because no one had the hours on it necessary to cook the panels.

I believe one of these samples is still looking good and the other is barely watchable because of how they are/were used. In the dedicated home theater my friend’s unit was on for 1-3 hours at a time to watch a movie or two then shut down. In our combined home theater/living room the projector was used for both movies and general TV watching. Its death was hastened when my son hurt his foot and spent the all summer long recovery process watching hours of movies, games, and cable TV. It was after this stint of being on 8-16 hours a day I noticed the beginnings of the blue discoloration.

When the second bulb in our AE700 was used up I could not bring myself to spend $375 to watch 1/3 blue HDTV. As a stopgap I purchased a factory refurbished 1024x768 DLP projector for less than the cost of a new bulb for the AE700. The picture is not bad, I can see it is not as good as the new AE700 was or the 1080P Toshiba flat panel we have in the den, but the family thinks it looks good. My hope is by the time the XGA DLP projector needs a new bulb the market has an affordable 1080P inorganic 3LCD or DLP projector using LED lighting.
Isaac Kuo Posted Jul 31, 2009 8:56 AM PST
I've never understood the problem with the "screen door" effect. If you want to eliminate the screen door effect, you just slightly defocus the lens. This eliminates the edges with a smooth gaussian blur.
Tim Posted Jul 31, 2009 9:49 AM PST
I find 3LCD to be a flat technology. It's gone about as far as it can go in terms of applications. Can 3LCD project a 3D image from a single projector like the new DLP units can? With all the new movies coming out in 3D from Hollywood, I want to make sure I'm going to get a HT projection system that can show movies the way they were intended to be seen.

For me DLP is the only way to go. You don't have to worry about color decay and cleaning filters. When I change the lamp on my DLP projector, the image looks just like the image when I bought it 3 years ago.
Mischa Lockton Posted Jul 31, 2009 8:58 PM PST
As someone that both rents out projectors and easily gets DLP rainbows + headaches, I refuse to look at DLP ever again- it hurt my head besides ruining the content.

I also would not want to subject any of the audience to possible artifacts that I may not even see myself- even 1% of the paying audience is unacceptable. Therefore, while newer DLP based projectors may reduce or eliminate the problem for a larger % of people, I can't take that risk!

I can verify the 3-chip models are totally different with no artifacts, but those are too much money.

Sorry TI, I loved my speak-and-spell, but DLP with spinning color wheels is never going to be an option for me!
Darin Posted Jul 31, 2009 10:24 PM PST
mikeb: "If an LCD panel can produce for example 2000 Lumens at white (all 3 panels on full), then how can it produce 2000 Color Lumens?"

The Color Lumens rating would be red by itself, plus green by itself, plus blue by itself. So you are right that red wouldn't be 2000 lumens, but if the 2000 Color Lumens is with color balance equal to D65 then the amount of red would be the amount that is called for by a standard when white is 2000 lumens, or in other words, red would be the correct percentage of white, not a lower percentage of white than called for (as happens with a white segment going where each color by itself is dimmer than is standard for that much white).
Magnus L Posted Aug 1, 2009 4:05 AM PST
this is just my 2 cents off future fortelling: I belive that single DLP Technology is gonna be the future technology when its combined with LED lighting technology...

it removes the color wheel and thereby RBE issue that has been a trouble for some (I am abit sensetive too) when it comes to DLP..and I Would not be surprised if Dithering artifacts will dissapear aswell since the LED can be adjust for brightness on every mirror.

this Adjusting the LED´s will make the DLP/LED projectors superior in contrast (already demoed prototypes with over 100000:1 ratio without an Iris). and since they have been superior in sharpness (atleast i think so) and much less motionblur (wich is a big issue for me) the DLP Technology will rule the future (unless LCD or LCOS do somthing about their lag!!!)

Comments welcomeon this....
Magnus L Posted Aug 1, 2009 4:07 AM PST
oh!! I forgot the Lamptime on the LED´s....was it 20000 hours expected...
brett Posted Aug 1, 2009 4:40 PM PST
LCD is a very tough sell to me at this point after experiencing the debacle that was the Sanyo PLV-Z3. The blue polarizer only lasted 14 months in an air-conditioned room with HEPA filtration, 800 hours of use, and filters cleaned every month. Sanyo of course insisted neglect of the filters like they were doing to everyone at that time and refused warranty service. As a result I replaced that unit with a Mitsu HD1000U DLP which still performs like the day it was mounted(now about three years ago) and the company I work for no longer uses Sanyo products.
kevinp Posted Aug 2, 2009 2:03 AM PST
I Suspect that LCD Projectors will be fast enough to do 3D by the time you are able to buy Blu Ray Discs / 3D Player with a "proper" 3D Standard. In the longer term I suspect Laser Technology may be the best.
Jason Posted Aug 2, 2009 11:43 PM PST
Does anyone know if LCOS panels are organic or inorganic? I have a canon SX60 that is coming to the end of it's 3 year warranty and have noticed some color artifacts in the corners(green and pink half round shadows) could this be dust or is it the panels burning out? I wait for the LCoS article with great anticipation.
Aamir A.Farooqi Posted Aug 14, 2009 9:02 AM PST
In terms of image balance my experience is that LCD's are much better then any DLP's. I couldn't see any normal range US$ 1200 to 2000 DLP Projector that gives true yellow color. Ofcourse color saturation is indeed an important element. Most normal range DLP's are cheaper then LCD's but if I get a balnced image in LCD @ 2500 or 3000 Lumens say 500:1 then there is no fun to choose a 2000:1 + and get unbalanced image. Isn't it???
Mike Posted Aug 17, 2009 9:58 AM PST
Great article! It's nice to read a up-to-date comprehensive comparison of the two technologies: LCD and DLP. I remember researching vividly a few years ago with my first projector, trying to read through all of the various articles to get a real-world assessment of which technology was better.

I cannot wait to read a follow-up article to this, LCOS (SXRD) versus LCD & DLP. Please get that article posted.
Nagappa Posted Aug 26, 2009 10:26 AM PST
A very enlightening article and echos my findings with low-cost projectors.

I have an Infocus X1 DLP with SVGA resolution and a Sanyo PLC-XW60 3LCD with XGA resolution. When using a video setup DVD to calibrate the projectors, I found the Sanyo (3LCD) did better with the video benchmarks than the Infocus (DLP). When projecting from a computer at SVGA (800 x 600) resolution, the LCD image was sharper than the DLP. The screen door effect is not so prominent on the 3LCD due to the smaller inter-pixel gap.

However, when watching home movies after calibration, I found the DLP to do a better job with colors and black levels in dark scenes. The LCD's colors were over-saturated in the darker scenes with an over emphasis on the reds and pinks. I had to re-calibrate the LCD projector to avoid this effect. The DLP projector seemed to have a more natural color contrast and balance at lower light levels, giving the impression of being more "film-like".

Therefore, my rule of thumb for low-cost projectors is LCD is better for PowerPoint while DLP is the better for home theater (if you are not able to notice the "rainbow effect").
Tony Glover Posted Aug 29, 2009 5:35 AM PST
I have to admit this has proven a very interesting article along with all the varioius comments. I myself was all set to purchase LCD and until I saw a DLP at the last minute. Both offered a very good picture in movie mode with the LCD possibly just better because of the blacks. I'm no expert, just a an average Joe but HD TV on DLP did seem more natural than the LCD. The other factor was a massive price reduction and a free replacement bulb sealed the deal.

It will be interesting to see if any of the problems with DLP occur over the next few years, but should projectors head the way of flat panel screens over the last couple of years, both LCD/DLP projectors will end up being a throw away item anyway and all this 'Mine is better than yours' discussions won't mean a thing...lol
Stunko Posted Sep 1, 2009 11:29 AM PST
Confusion still rulz, plus everyone has his/her favorite technology, anyhow.

Of all the different types of PJ display panel (chip) technology, only the monopolistic Texas Instruments is still peddling primitive single-chip models. Personally, I would not buy a single-chip technology projector for any money, whether it is DLP, LCD, LCoS, D-ILA, SXRD, or whatever. But then again, only TI still peddles single-chip DLP PJs anymore, so it is a rather easy choice for me as what NOT to get.

I would also not get any projector with no lens-shift and with only a fixed focal lens or a retarded 1.15x to 1.3x focal range zoom lens. So, that bars the single-chip DLP units once again.

Three-panel DLP PJs are better, but again due to the TI monopoly pricing, they cost at least 300% as much as they should really be going for. And they have many of the disadvantages of their single-panel color-wheel models.

I found that for the money, you cannot beat the JVC D-ILA PJs, as their projected image is just as good as that attainable with 3-chip DLP PJs for a fraction of the price. And it is a reflective technology, like DLP is. Colors are very much analog looking, so to me D-ILA will give you the color spacing closest to Fuji and Eastman positive (projection) film stock.

With respect to the light sources, hopefully by the Christmas 2010 shopping season, we shall have a good selection of LED-lamp source HT PJs in both DLP and LCD designs.
Dallas Posted Sep 3, 2009 12:42 AM PST
Thankyou for a well balanced opinion on the subject. I'm amazed at the amount of false propaganda there is on the web about DLP projectors, the LCD lobby needs to get over itself. I've been using a Sharp Z90 DLP HT projector for about four years (~3000 hrs on lamp). It's an early 800x600 model with a 1200:1 contrast ratio (low by todays standards), with lens shift and it has given me faultless brilliant pictures from the day I installed it. Weather it's dvd, digital tv and even my old vcr I've always been happy with it's performance. And I'd like to point out, contrary to the so called dlp review on the AIM web site on no occasion have I or my friends ever had a problem with the "rainbow effect", or Migraine headaches, or epilepsy. In fact the only way I've been able to see the dreaded RB effect is to dart my eyes around or move my head quickly back and forth, funny I've never needed to do that while watching a movie, at home or at the theatre. I'll stop my rant now except to correct one comment, the D-ILA light engine isn't like the DLP, in the D-ILA the light source still passes through the LCD to get to the mirror. When I upgrade to 1080p I'll be going DLP, but each to his\her own I suppose.

Great article Evan.
Vasastan Posted Sep 6, 2009 11:52 AM PST
Great article! Regarding the LCD lifespan issue, my Panasonic PT-AE700E has just developed a blue "stain" across the right third of the image. It was bought in 2005, and we have used it pretty heavily since then - about 3500 hours (!) on the first lamp, close to 1000 and running on the second. We have used the low lamp, low fan mode throughout. The filter is cleaned occasionally, although not as often as recommended. I feel a bit cheated by Panasonic (and other LCD projector manufacturers) for not warning about this before. Coming from an engineering background, I find it hard to believe that they would release a consumer product without extensive life and stress testing of the components, so they have most probably known about this issue for a long time.
Doug Posted Sep 10, 2009 4:50 PM PST
With LED light sources coming on line in he next few years, this could give the DLPs larger market share. LEDs are a good fit with DLPs because elimination of the color wheel costs and also thereby eliminating the need to throw away 2/3rds of the light. Assuming the the Vivitek review performance is the shape of things to come, LED/DLP photons will be hard to beat. Full On/Off contrast 100,000:1 ANSI contrast 844:1 Large color Gamut
b. scott Posted Sep 11, 2009 7:00 AM PST
Brilliant article! Just a comment about "rainbow effects", as a visual artist having experienced this with DLP projectors, it's not like the other plus/minus comparisons between the technologies, the nausea induced by the rainbow effect, which lots of people experience to varying degrees, in my case is so intense, it's the visual equivalent of being shot in the face, or jumping out of a plane without a parachute. if you don't experience it, it's easy to dismiss as a minor consideration, but those who do experience it intensely won't, in fact cannot, watch DLP under any circumstances. so for home theatre, which only has to work for the household and friends, DLP might be fine. but if you are projecting to a wider audience, it's just about the most important thing to consider, far more important than any differences a projector might have in lumens, contrast, color saturation, etc.
Marc Posted Sep 15, 2009 6:55 AM PST
Like Richard, I have owned many projectors (12) in the past 10 years due to entertainment conferences I run multiple times a year. We use the projectors with computers and Blu-ray. DLP just blows LCD out of the water for quality of picture. It just doesn't make sense to me that someone would still purchase LCD.
Nazeneen Strickland Posted Sep 15, 2009 8:20 AM PST
Wow i didnt think of it like that.I didnt know how much computers are worth and their value to others.I didnt realize howdiffernt and expense computers just because of their charistics.
steve Posted Sep 22, 2009 2:42 PM PST
Quote:Posted Sep 3, 2009 12:42:44 AM By Dallas Alert Moderator

Thankyou for a well balanced opinion on the subject. I'm amazed at the amount of false propaganda there is on the web about DLP projectors, the LCD lobby needs to get over itself. I've been using a Sharp Z90 DLP HT projector for about four years (~3000 hrs on lamp). It's an early 800x600 model with a 1200:1 contrast ratio (low by todays standards), with lens shift and it has given me faultless brilliant pictures from the day I installed it. Weather it's dvd, digital tv and even my old vcr I've always been happy with it's performance. And I'd like to point out, contrary to the so called dlp review on the AIM web site on no occasion have I or my friends ever had a problem with the "rainbow effect", or Migraine headaches, or epilepsy. In fact the only way I've been able to see the dreaded RB effect is to dart my eyes around or move my head quickly back and forth, funny I've never needed to do that while watching a movie, at home or at the theatre. I'll stop my rant now except to correct one comment, the D-ILA light engine isn't like the DLP, in the D-ILA the light source still passes through the LCD to get to the mirror. When I upgrade to 1080p I'll be going DLP, but each to his\her own I suppose.

Great article Evan.

Dallas: I wish to correct your earlier post "that in the D-ILA the light source still passes through the LCD to get to the mirror". This is wrong.

JVC D-ILA is LCOS technology, as is Sony's SXRD. Light is reflected off the chip face, rather than passing through it as it would a LCD panel. It is reflective not transmissive of the light source, just as in DLP.
Hernan H Posted Sep 22, 2009 7:50 PM PST
I´m From south america. It`s important? YES, because we see a lot a movies in english with subtitles...and when you look up and down reading the subtitles...or you finishing reading a subtitle..your eyes go to down-right the screen..and then...you move your vision up.. this contiuous eye exercise makes the Rainbow effect more noticiable...I know DLP has more contrast...the LCD degrades (yellow spots in less than 2000 hours) but...I cannot live with the Rainbow eff. everytime I move my eyes from the movie to the subtitle...and so on.... Just my subjetive opinion...( sorry for my english!!)
Sunny Mathew Posted Sep 29, 2009 3:01 AM PST
We are a christian organization using the projectors for presentation of Gospel. we are having 325 LCD projectors, and recently purchase 100 DLP projectors. In the beginning we were using a single chip LCD projector and the brightness of the projector remained for the same after 1000 hrs of use. but when we start using the Panasonic 3LCD projectors, the performance was very good in the beginning and the brightness came down after 500 hrs of use and after 2000 hrs, even after changing the lamp with a brand new lamp the brightness is very very poor. My question - will this happen to our DLP projectors, we are using for the outdoor programs? can any one answer?
Scott Posted Oct 7, 2009 11:09 AM PST
I have found that in budget projectors, we have better luck with LCD models over DLP. They have better color overall. Our DLP projectors had the wheel start to loose it's color, loosing the intensity of the colors except for while. But in High End projectors, In DLP they tend to add more colors to the wheel and have a better Image. Lower end=LCD generally better, Higher end=DLP generally better. Both have improved a lot from where they've come from
Glenn Posted Jan 22, 2010 3:45 PM PST
I would like to say that the article was well written and thought out covering the pros and cons of both technologies. From my experiences, (Pany PTAX200U 3LCD home theater projector), I would have to conclude that the technology you choose is dependent on your application. After 1800hrs my pany developed a yellow blob that started spreading. It is currently in the shop for repair. Polorizer replacement. I bought my pany because I had the idea that I would use it sparingly to watch movies, occasional sports and HDTV events perhaps 1-4 hours per day. Also what sold me was my ability to place it where i wanted and to take it out on the deck for outdoor movie night. Well the big screen, 120' silver cinema, and projector combination was so enjoyable and crisp that it was hard to resist not using it for everyday watching. That upped my hours to 6 hours a week night and 10 to 12 hours during the weekends. There is a small disclaimer in the manual that says if watched for more than 6 hours at a time it is possible that repairs may be needed within the first year. Well I'm experiencing that. At first I was mad and upset that this product was so wretched. After I got over my inital shock that my projector was down I have made decision to prolong the life of my projector. A pop up flat panel for daily viewing and of course the big screen for event and family times. Again I cant stree enough that purchasing the right technology for the right application will ease your headaches. If you want to replace your TV with a projector then DLP is a great way to go unless you have placement issues or issue with rainbows. If you use your projector for a Dedicated home theater the picture quality, contrast, lumens, and price point can make both technologies very attractive.
Steve Linke Posted Jan 23, 2010 12:14 AM PST
Nice article. Could anybody direct me to where I could get a copy of the Texas Instruments DLP vs. LCD testing, which was apparently published back in 2003? Thanks.
David Posted Feb 2, 2010 8:44 PM PST
With 3d-ready projectors hitting the market, it might be time to update this article with a discussion of the effects of each technology on 3d content (i.e., image persistence).
Medenyx Posted Mar 11, 2010 5:35 PM PST
Agree with you David!
ron Posted May 28, 2010 7:44 AM PST
guys what is better 3LCD or DLP projectors? What should i buy for a shop window? To get good image in day light also
Mark Laposky Posted Jun 3, 2010 5:50 PM PST
Just exactly what I was looking for! Thought that I would never find it. Good article & unbiased. But, after reading, I've decided to go DLP and am now concious of the importance filters and seals. Thanks.
SDavies Posted Jun 6, 2010 6:19 AM PST
The statement that DLP chips do not degrade is no longer true. There is a now well-known propensity for the miniature mirrors on these chips to break down, sometimes after less than two years, causing a rash of white and black dots on the viewing screen. This ruins the quality of the viewing experience and is an expensive repair. It is happening to my Mitsubishi 65" flat-screen now (after the warranty period, of course).
mikyla Posted Sep 15, 2010 9:32 AM PST
THIS IS ALOT TO READ!
leslie r Posted Sep 15, 2010 1:11 PM PST
i think this artical is about LCD's and how the they work and contribute easier access to what the LCDis showing. And then lower down the artical there are some people who wrote what they thought on this artical. The LCD projector shows what you want to show without a blure.
Anyely Posted Sep 15, 2010 1:16 PM PST
I think this articles were pretty cool because they talked about LCD and DLP and it explain what they are and how they work :0
leslie r Posted Sep 17, 2010 12:52 PM PST
i think if you really read it and take the time to understand it all it really does make sense!
David Berry Posted Oct 16, 2010 3:50 AM PST
Isn't it time to update this article to reflect the availability of LED illuminators for DLP projectors? The advantages of LED illuminators are that they are long life (>30,000h) and since they can be pulsed at very high speed, their use in place of the colour wheel addresses the historical issue of the colour break-up, or 'rainbow' artefacts. Certainly the way to go!
David Holloway Posted Dec 28, 2010 5:20 AM PST
Have had a DLP Optoma HD65(720)projector for approx. two years and have been very impressed with it. Initially, I was a little apprehensive that such a small unit could give out such an amazing image and with such quality (I grew up with film both in cine and slide with all its problems of dust, hairs in the gates, camera & projector, and most importantly light output; the one advantage it seems to me was the quality of lenses and focal lengths). This article has provided me with a greater knowledge of both systems and as I now wish to upgrade, a help in making a decision between DLP & LCD. I say 'help' but not a firm decision as although in favour of DLP I find the lack of optic flexibilty a drawback in projector placement; in fact there seems to be a distinct lack of info in respect of the optical specification in all models, unlike film projectors. The comment by Thomas on this aspect I concur with and ask the same question.
heidi Posted Feb 21, 2011 10:17 PM PST
Is there less than a kilo projector? Which technology is cheaper over time?
lynn Posted Mar 3, 2011 10:26 AM PST
I would like a projector for under $500 to watch dvd's in my back yard. Any suggestions. thanks!
abhinav Posted Jul 25, 2011 8:25 AM PST
The article helped me a lot, i want a good HD projector under 700$ any suggestion ..
VAN Posted Nov 28, 2011 10:42 AM PST
The one real disadvantage LCD not mentioned is the picture breakup(pixelation/motion lag)if there is motion in the picture. Its still quite noticeable on top of the line 240 hz refresh TVs. And I would assume on projectors too. To me at least it gives me a weak knee feeling almost like standing in a small boat. I get a light headed almost sea sick feeling while standing if I look at a display for more than a few moments. I haven't tried watching sitting down as I only have watched them in stores while standing. Note: I do own a DLP projector and the picture quality is vastly superior to LCD TVs with a lot of motion in the picture.
Jorge Posted Dec 6, 2011 3:48 PM PST
Bought a Viewsonic PJ551D (DLP) for 600 Euros and after 2000 lamp hours (2 1/2 years) black and white pixels started appearing on the screen. At the beginning only a few, after a few weeks half of the screen was covered with damaged pixels. Such a product should last more than this. Should have gone to the movies...
Chris Posted May 10, 2012 11:17 AM PST
I had the same problem. This product has a 3 year warranty. They fixed it for me. 8 Month later I had the same problem again and I was out of warranty. If you are still in the 3 year window call them and get it fixed.

- Chris -
stolennomenclature Posted Aug 13, 2012 2:56 AM PST
The comment in the article re LCD projectors lasting 4000-10000 hours before the onset of lcd panel degradation is disconcerting. Not just because the figures seem to me to be so very low, but also because the author seems to be quite happy with these very low figures. 4000 hours is about the same lifespan as the average bulb, and 10000 hours only just slightly more then the lifespan of two bulbs. In the 4000 hour projector you would never even get to change the bulb, having to change the projector at the same time. In this case the manufacturer might just as well solder the bulb in. The longer lived projector would only get part way through its third bulb before you would want to chuck it. To me this situation is quite absurd. I would expect to get much more life out of a product costing this kind of money. To me the absolute minimum would be 60,000 hours for a cheap one, and say 100,000 or more for a top of the range one.
Anthony Posted Sep 7, 2012 7:16 AM PST
I own a Sony 3LCD VPL-AW15 and it has been used sparingly over the course of almost 4 years for about 900 hours on its original bulb. I really like the natural tone of the colors and the contrast compared to other projectors, although it could use a little more brightness. Relatively recently though, I purchased from ebay a Sony VPL-VW50 SRXD projector in mint condition with a replaced compatible bulb with barely 180 hours on it. Obviously, the picture looks much sharper on the VW50 because it is a full HD projector but I think the colors look a little bit better on the lower end Sony. Obviously, it could be just a matter of calibration. One thing I really enjoy about the VW50 is the motor assisted lens shift and focus, it just much cooler than dialing it in with the nobs on my other projectors. I received yesterday a new LG PA70G from fry's and I'm experiencing the focus uniformity issue prevalent with this new model but I'm going to have to live with it. I love how small and light the LG is and that at least now I can dispense with the bulb life anxiety. I don't have a lot of experience with DLP projectors except a really crappy 800x600 res projector we use at work for presentations. I wouldn't mind trying a quality DLP projector first hand to see the difference in person. So far, I'm pretty satisfied with my LCD projectors, especially for the price I've paid for them ($1000 for the new one with an 80" screen included, $600 for the used Sony and $460 for the LG)
Jackey Wordstooln Posted Dec 23, 2012 10:39 AM PST
I didn't know LCD means liquid crystal display until I've read this post. Thanks so much for educating me. My Last Post: <a href="http://marketbold.com/KeywordMapPro/">Google Wonderwheel</a>
B Rivers Posted Nov 30, 2013 8:36 PM PST
Having designed, installed and serviced projection systems in corporate, museum and other environments for 20 years, it is my experience that LCD panel degradation is a serious concern that should be considered in any application where projectors run for more than a couple hours at a time. The high heat and intense UV output of projection lamps causes LCD panels to breakdown, especially in high brightness models, and the effects of this can be quite severe, typically burning up the blue panel first. I think it is an understatement to represent this merely as "a color shift", as the result is seen as a large black hole in a blue image, or a large yellow area in the center of a white screen. I've discussed this with engineers at many projector manufacturers who make both LCD and DLP products, who've confirmed that all LCD projectors, even those with inorganic elements, are subject to this degradation, and therefore are not recommended for applications where the projectors will be used for long periods of time. Inorganic versions do last a bit longer but still suffer from the same problem. The cost of servicing a projector with a burnt up LCD panel can be quite high, I've seen repair costs of $1500 or more for replacing the panel in a 3500 lumen conference room projector, not including the cost of shipping the unit back to the manufacturer/service center. Anyway, my advice and general rule of thumb is LCD is fine for applications that will see sporadic use for short periods of time, but for critical environments and applications where projectors need to run for extended periods of time, I strongly recommend DLP. There are of course exceptions to every rule, and for those who are amongst the small percentage of viewers able to perceive the rainbow effect of single chip DLP, find it problematic and understand the potential accelerated need to replace/service LCD projectors and can afford to do so, they may choose to go with LCD, but make sure you understand the considerations.

One final note: The potential color saturation advantages noted for LCD models only apply in comparison to single chip DLP models. Professional three-chip DLP projectors provide the most accurate color reproduction, which is why digital cinemas and high end staging companies use them almost exclusively. (One exception: Christie Digital has recently shown a prototype 4K laser projector for very large digital cinemas, not to be confused with small, low cost LED/laser hybrid projectors) These are truly professional grade models, and are not available in low cost versions, three-chip DLP projectors start at $20K+, ranging up into the stratosphere for extremely high brightness (flamethrower) models that can drive enormous screens, but for critical applications and large venues are the tools that can really get the job done.
WMAKA STEVE Posted Mar 18, 2014 6:00 AM PST
hi......... i have installed and worked on LCD projectors since 2008.but i would recommend buying dlp since its the in -new thing . lcd suffers the chicken like effect of door light
reiNbow Posted Nov 21, 2014 10:20 AM PST
Hmm, to expect a product lifetime of 100 000 hours is over the top I think. It would be equivalent of watching movies for 8 hours per day, every day for 35 years.
Jeff Posted Sep 8, 2015 9:20 AM PST
Is there a planned update to this article? Curious that the dip dmd chip/white dot problems are not considered a limitation of the technology. Does the three chip dip implementation offer any remediation to the single chipset problem of a mirror in the on/off position? Is the problem an artifact of a low quality chip implementation or the technology? BTW, I have an Optoma ep721 and love the picture, but the dots just come back no matter what I do.
Eric Posted Mar 8, 2016 12:01 PM PST
Agreed, I just had a BenQ DLP start with a couple of white dots and now it's half the screen. In the $1000 and less market, I would rather have a LCD project that loses some color over the years than a DLP that is not usable what so ever after a few years. For a price, BenQ can replace the chipset but for the price you might as well buy another projector.
Fran Posted Sep 25, 2016 6:42 PM PST
I have purchased a viewsonic PJD6211 DLP proyector. The fist at 700 hours fail, appears a lot of white dots. But dont worry, I have guarantee. The second unit seems good, but at 350 hours failed tood, appearing a lot of white dots. The people need to know that this is a current fail from DLP chips inside DLP projector. These chips cost about $150-$200 and could fail again. I used now Epson LCD, and I know tha color may deteriorate in time, but prefer this than a dead one unit and 400$ lost. Viewsonic NEVER gave me a answer. But if you investigate you will know DMD chips fails often!
Vince Posted Jan 23, 2017 5:08 PM PST
Thanks for refreshing my mind about LCD vs DLP projectors in your article. I did similar research back in 2007 and purchased a Sanyo PLV-Z5. This LCD projector has 3892 hours on it as of this comment and came with a spare lamp. I have never replaced the lamp. The image has one defective pixel near the bottom left corner of the screen and is only noticeable occasionally. I have been extremely please with this projector. It has great place-ability with shift lenses in the horizontal and vertical planes. Give what I read in the comments, I think I would stick with LCD again on my next unit. I am only looking because it would be nice to take advantage of 4K technology. But I think there is still a lot of life left in this 10 year old projector.
James Posted Mar 9, 2017 4:06 AM PST
Hello Everyone. I was wondering if you would get the same panel degrade on a DLP Laser projector as you would on a standard discharge lamp source DLP projector. Does the change in light source have any effect on the panel lifespan?. Thanks
Pete Posted Nov 5, 2021 2:12 AM PST
I read both the article and the comments. I must point out that the article is outdated by 2021 but, on the other hand, there are not similar posts on the Internet comparing LCD & DLP technologies. Is for this reason that I will try to contribute to it.

I own a Dell M115HD projector with DLP+LED technology. Bought in 2015, it has only lasted 5 years with just 600 hours of use. Yes, I have only used it to watch movies occasionally on weekends (maximum 2-3 hours per session). I have had extreme care of the projector and conscientiously used the ECO mode for less brightness intensity. When approaching the 600 hours, it begun developing dot & white pixels, which were not very annoying at first. However, after a couple of more uses the whole screen became rapidly bloated with hundreds of dead pixels and now it is just unusable.

So, what is going on with LCD & DLP technologies beyond what the article tries to explain?

Firstly, LCD is ubiquitous (TVs, laptops, monitors, phones, etc.) and we all have a good idea on how mature and reliable this technology is. The problem when putting LCD panels on projectors is the intensity of light (and heat) they end up receiving. Therefore, you can expect a certain colour degradation over time. This will occur after few thousands of hours of exposition (which is in agreement with the experiences reported by the people in the comments).

On the other hand, if you try to understand how the DLP technology works, you will soon realise that it relies on micromirrors switching back and forward thousands of times per second. Each micromirror represents a pixel and is exposed to that intense LED light and heat. From a mechanical engineering point perspective, the stress and fatigue at which these micromirrors are exposed are orders of magnitude higher than LCD panels (organic or inorganic). This is mainly because there are not moving parts on LCD panels. Therefore, it is understandable that DLP technology will be more prone to failure, and that its lifespan will be much shorter and noticeable than LCD technology.

Nowadays you can find 4K DLP+laser projectors that can be bought from £4000. My advice is that you make your own choice based on an educated decision. As a corollary, do not try to replace a TV with a projector for daily use since the latter will just break much much sooner than the former, regardless of the technology being used.
Clay Wisner Posted Oct 19, 2022 1:28 PM PST
This article needs an update to take the Laser light source models into account, along with improvements to both technologies since 2009
Rob Sabin, Editor Posted Oct 19, 2022 4:02 PM PST
Been done:

LCD, LCoS, or DLP: Choosing a Projector Imaging Technology

https://www.projectorcentral.com/Digital-Projector-Imaging-Technologies-Explained.htm

Lamp, Laser, or LED Projection: Which Light is Right?

https://www.projectorcentral.com/Which-Light-is-Right.htm

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