Business Projector Buyer’s Guide
August 5, 2008 on 10:44 am | In Projector Buyers Guide | No CommentsThings to look for when purchasing a conference room projector:
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.
Things to consider before buying a projector
January 14, 2008 on 9:33 pm | In Projector Buyers Guide | No Comments1. Resolution - What is the main use for the projector?
If is to show powerpoint presentations for a business, school or church etc. you will typically go with XGA resolution. This is a 4:3 format you see on most computer monitors. If you are on a tight budget you can save $100 or so by downgrading to SVGA resolution but in my opinion the loss in image quality is not worth the savings. Additionally, you can also upgrade to a higher resolution model (SXGA or WXGA) if your presentations contain highly detailed graphics and or wide format images.
If the projector is going to be used for movies and home theater applications then you would typically go with a wide screen format projector (i.e. 16:9 ratio). Note: there are different levels of wide screen format projectors - Low End (854 x 480 pixels), Mid Level (1280 x 720 pixels), High End (1920 x 1080 pixels). The more pixels the better the image and higher the cost.
2. Brightness (measured in lumens) - Again, what is the main use for the projector?
If is to show powerpoint presentations for a business, school or church etc. you need a bright projector. A standard classroom or conference room with some ambient light would need 2000 to 4000 lumens. A church or large auditorium typically needs 5000 or more lumens.
If your projector is for a dedicated home theater that has limited or no ambient lights 1000 to 1500 lumens is typically sufficient.
3. Contrast Ratio - The difference in light intensity between the brightest white and the darkest black. A higher the contrast ratio is better than a lower one.
Medium Contrast (400:1 to 1000:1)
High Contrast (2000:1 and up)
4. Inputs - the connections on projector that enable you to hook it up to other types of equipment (i.e. DVD player, Computer)
If you are doing powerpoint presentations you will need a VGA connection. This is standard on almost all projectors that are not specifically geared towards home theaters.
If you are buying a projector for a home theater you will want to get a projector that has digital video inputs (i.e. HDMI or DVI). These inputs will enable you to watch High Definition Television and DVD’s.
5. Weight - If you plan on taking your projector on the road for mobile presentations you may want to consider a model with a small footprint. Typically, 3-6 pound projectors are preferred.
6. Noise (measured in dB’s).
0 dB is the threshold of hearing
10 dB is barely audible
20-30 dB is a soft whisper (dB levels in this category are usually found on home theater projectors so that projector noise does not interfere with movie experience)
30-40 dB is a whisper or the hum of a refrigerator (most business projectors fall in this range)
40-60 dB is the noise level of rainfall or a normal conversation (some very small projectors and some very large projectors have dB’s in this category, this is due to the fan noise required to keep the unit cool)
7. Warranty - projector warranties typically range from 1 to 3 years. While it is rare that warranty service is needed…it does happen. If you are comparing models with similar specs the projector warranty should be a factor in your final decision.
8. Replacement lamp price. Most replacement bulbs are estimated to last 1500 - 3000 hours (sometimes more…sometimes less). That means that depending upon how much you use your projector you will periodically have to spend ($200-$500) on a new lamp. Once again, when comparing models with similar specs it should be a factor in your final decision.








