DLP and LCD are the two main types of conference room projectors.  While the gaps have been bridged significantly through the years as technology has improved, there are still some basic fundamental differences that you need to consider. Business projectors with DLP technology use a single chip made up of several thousand, sometimes millions of tiny mirrors that reflect light to produce an image.  DLP units are typically lighter, with smaller housings than LCD models.  LCD requires three LCD panels, which makes for brighter pictures, but more difficult for manufacturers to produce ultralight portable units. It has been claimed that DLP projectors last longer than LCD projectors, but are more expensive.
 

DLP
DLP (digital light processing) is a proprietary technology developed by Texas Instruments.  Business specific DLP models will come with one DLP chip that is made up of several thousand, sometimes millions of tiny mirrors. Each mirror accounts for 1 pixel, or single point of light, in the image.  Light from the projector’s lamp is reflected off of the mirrors which either wobble “on” to direct the light towards the lens or “off” directing the light away.  Business model DLP projectors use a color wheel to modulate the color of the image.  This wheel spins in the light path between the lamp and the DLP chip and the filters determine the color of the light hitting the chip.
 

            Pros:  A key advantage is its portability, DLP technology can be used in small, ultralight projectors to enable them to deliver a high fidelity picture that rivals much larger units.  In fact, all of the projectors under 3 lbs. on the market today are DLP projectors.  If you’re looking for a model that can be carried along easily in your briefcase, DLP would be the best choice.  Another advantage is that the distance between each pixel, or inter-pixel gap, is very small on DLP projectors.  LCD based projectors typically have wider gaps, making the pixel structure more visible, causing a “screen door” effect.
 

            Cons: One downside is light leakage around the mirrors, which generates a sort of halo on some images. Newer DLP projectors use a “dark” chip, which uses a dark undercoating on the undersides of the mirrors to eliminate this problem.  It’s also important to note that some lower end DLP models use lower quality color wheels.  Lower quality wheels can not only produce poorer color saturation, but can also produce a “rainbow effect’, which is a visual artifact in the image.  Most newer models have a wheel that is 4x speed or faster and will not have any rainbow effects, though some people are more sensitive to it than others.  Check the specifications of the color wheel for the model you’re considering.
 

                                    If a DLP projector is best for your business needs, keep these things in mind at purchase:  
                                    Resolution- XGA (at least 1024×768 pixels) or UXGA
                                    Contrast Ratio- 600:1 or greater
                                    Brightness- 1500 lumens or greater
LCD
LCD (liquid crystal display) projectors place three LCD glass panels in the projector, one for red, one for green, and one for blue.  Light passes through the panels and individual pixels open or close to produce the image.
 

            Pros: Images are generally brighter, and LCD will produce more saturated colors, which also leads to an image that seems brighter and more vivid overall. LCD images are very sharp and clear. LCD has the upper hand over DLP in terms of the rainbow effect, which is an occasional artifact visible on the DLP screen to some viewers. The rainbow effect does not occur in LCD projectors. Where color reproduction is an important factor, LCD is often the preferred technology. In general, LCD projectors offer excellent performance at a good price. Earlier limitations in terms of pixilation and contrast have been overcome in newer projectors, and LCD projectors can be used effectively in a wide variety of applications.
            Cons: In some cases, especially when projecting video, pixilation can be more noticeable with an LCD projector, although with an XGA or higher resolution it is not a            problem. The result is a “screendoor” effect, which is caused by the inter-pixel gap. LCD has weaker contrast than DLP projectors, which makes it less desirable for video.       Another minor problem with LCD is long term degradation. Tests have shown that over time, some LCD panels will degrade, which will cause a shift in the color balance and reduced contrast. This is especially true in the blue panel. This may lead you to eventually replace the LCD panels in your unit which is costly. 
 

Brightness
 

To find the right conference room projector for you, first consider your circumstances. Take into consideration how large the room is, how large the projected image must be in order for the audience to see it clearly, and if you want your audience to be able to take notes or refer to written material.  Determine the level of brightness you require in a projector.  A low lumen projector may cost less, but you will have to project your image in a darkened room. Whereas the higher lumen projectors allow more flexibility.  A totally dark or dimly lit room is usually not necessary, but for best screen viewing, presentations should be done with the room lighting somewhat reduced.
 

            Brightness Guide:
 

            500-1000 lumens = 5′ to 6′ (152cm-183cm) screen in a small room with 5-10 people and no lighting
            1000-1500 lumens = 8′ to 10′ (244cm-305cm) screen in medium room with 10-30 people and dim lighting
            1500-2000 lumens= 12′ to 25′ (366cm-762cm) screen in large room with 30-100 people and  window or ambient lighting
            2500 lumens= audience less than 100 people with ambient lighting
            3000 lumens= audience of 100-200 people with ambient lighting
            5000 lumens= audience of 100 or more with bright lighting
 

DLP vs LCD:
LCD in general is more “light efficient” than DLP. When using the same wattage lamp, the LCD would produce a brighter image than the DLP. With a data signal, if using a 1000 lumen LCD next to a 1200 lumen DLP, most people would probably prefer the LCD for brightness.

Resolution
The resolution of your projector will be the main factor that determines how sharp and clear your picture will be.  In general, the higher the resolution the better the quality of picture will be.  You will see more detail and it will be less grainy and pixilated.  The resolution of the projector should match the resolution of the computer that will be used with it.  If you are not planning to display a lot of complicated or detailed graphics, a lower resolution projector will be adequate. The lower the resolution, the more money you will save.
            Resolution Guide:
            SVGA (800×600 pixels)= basic PowerPoint presentations
 

            XGA (1024×768 pixels)= spreadsheets and displays with columns of numbers
 

            SXGA (1280×1024 pixels)= technical drawings, small details(CAD/CAM applications), and detailed graphics
 

            SXGA+ (1400×1050 pixels)= detailed photography and data graphics
 

            UXGA (1600×1200 pixels)= very detailed

            Pros:
 

            SVGA which is most common is the least expensive
            XGA is adequate for most needs and is very affordable
            SXGA is used where there is need for showing small details
            SXGA+ is available in both budget and high-end configurations
            UXGA is for very high resolution workstation applications that are detailed or information intensive and support a broad range of computer equipment
 

            Cons:
 

            SVGA is at the low end of the scale and all though still available, are generally being replaced with XGA
            XGA is not adequate for engineering drawings, digital photography, or other images of a highly detailed or technical nature
            SXGA is considerably more expensive
            SXGA+ is overkill for text display or PowerPoint presentations
            UXGA is very expensive
 

DLP vs LCD:
In general, higher resolution shows more detail and provides a better quality of picture. In some cases with LCD projectors, especially when projecting video, pixelation can be more noticeable, although with an XGA or higher resolution it is not a problem. For the best picture quality with a DLP projectors it is suggested that the XGA or UXGA are best.  

Contrast Ratio
           
Contrast Ratio is the difference between the whitest white and the darkest black colors that the display can show.  The higher the contrast the crisper your images, the more vibrant your colors will be, and the better the color representation. When a projector provides good contrast, images are clear and attractive.  Projectors with a lower contrast ratio may become difficult to see clearly and tend to appear washed out and faded. Room light substantially impacts contrast ratio.  
            Contrast Ratio Guide:
            500:1 or less = low contrast
            500:1 to 1200:1 = medium contrast
            1200:1 or more = high contrast
 

            Pros:
            In a darkened room, contrast will be important for accurate display of graphics and video. In a room with moderate lighting a 400:1 contrast and a 1500:1 contrast will look almost identical, all other factors being equal.
            Cons:
            In a room with a good deal of ambient light, blacks look less black, so lumen output will be more important than contrast.
 

DLP vs LCD:

DLP projectors are able to achieve a higher contrast. LCD is often the preferred technology when color reproduction is an important factor, even though they have a weaker contrast than DLP projectors. Regardless, both the DLP and LCD projectors will produce a clear and vivid picture, especially with a higher resolution.

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