Ideal for delivering lectures and presentations to large groups,
as well as watching movies and other videos, projectors can be found in a
variety of environments, including classrooms, conference rooms, and
even home theaters. Projectors range in size and capabilities, from
handheld devices that need a dark room to deliver a viewable image to
high-powered devices that are easily read, even in brightly lit offices.
Projectors can be purchased from electronics retailers or specialty
stores dealing in camera and projection equipment. For consumers who
prefer to shop online, sites like eBay are excellent options. This
buying guide will discuss the differences between three kinds of
projectors: LED, LCD, and DLP projectors.
The technology used in projectors can generally be broken down into two types: transmissive or reflective. Because LCD projectors pass light through the LCD panels rather than bouncing it away, they are considered a transmissive medium. A DLP projector uses mirrors to direct the light in an image, so it is considered to be "reflective." The third type of projector discussed, an LED projector, is named for the light source, not the type of projection technology.
LCD projectors have been around since the 1980s, and the technology is more reliable than film projectors. However, they may still require maintenance, as pixels can burn out and dust particles can interfere with image quality. On the other hand, LCD projectors have no moving parts, as DLP projectors do, and they are generally less expensive than their DLP counterparts. They also support setups in larger rooms where a greater projection distance is needed, because they are compatible with zoom lenses and lens shifts.
As previously stated, LED projectors are defined not by the display technology used, but the lighting. In fact, some DLP projectors with "solid-state illumination" technology are actually LED projectors. Another type of projector, the pico projector, commonly uses LED technology as well. Pico projectors are essentially handheld devices that use LCoS (liquid crystal on silicon, which is similar to an LCD panel but reflective rather than transmissive) or DLP technology. In these cases, the projector replaces the traditional lamp with longer-lasting and more efficient LEDs, colored in red, green, and blue. In DLP projectors, this also replaces the color wheel technology, instead letting the red, blue, and green LEDs shine directly on the DMD chip.
Beyond the technology used, however, there are other significant differences. LCD projectors are typically less expensive for smaller venues, such as home theaters. They also give the user the advantage of a longer throw distance and greater zoom capability, both of which are lacking in many DLP projectors. This makes LCD projectors ideal for larger environments. However, DLP projectors do not suffer the color decay that LCD projectors do and they are easier to maintain because of their filter-free design.
DLP projectors with LED technology are even simpler because the lamp will not need to be replaced, saving time and money for users. Pico projectors that use LED technology have the same long life, but are designed to be ultra-portable, connecting to smartphones, tablets, and other mobile devices. As such, they do not offer the same high levels of brightness found in larger projectors. They typically have a brightness of less than 200 ANSI lumens, whereas larger projectors can have a brightness of 1000 ANSI lumens, up to 4500 ANSI lumens or more.
When you’re ready to buy a projector, start by visiting eBay’s
Electronics department, and navigate to Computers, Tablets, &
Networking. By Selecting "All Categories" followed by Monitors,
Projectors, & Accs, you will have the option to filter results to
just Projectors.
From there, you can further filter your results by the type of
technology used, whether it is LCD, LED, or DLP. You can also narrow
down options by factors like brand, image brightness, resolution, aspect
ratio, and more. In addition to navigating the site this way, you can
simply enter a keyword, such as "DLP projector" into the search box on the eBay home page to be presented with hundreds of choices.
You may also want to look for Top-rated Sellers, who have high ratings and positive feedback from shoppers who have bought from them before. eBay’s Advanced Search function lets you display results from only Top-rated Sellers. In addition, you can search for items from specific sellers if you know their ID or have added them to your "My Saved Sellers" list.
Four Main things to look for:
1). The type of projector - LCD, DLP, CRT
2). The Lumens output (brightness) of lamp - 800-1000 is good for LCD,
DLP at 1000 is good. Dont get it to high or colours will look poor, less
than 1500 is really needed for good colour reproduction.
3). The Resolution. For optimal picture make sure to get XGA or WXGA. A
cheaper method is VGA/SVGA, but if you can get XGA or higher you wont
regret the moeny spent.
4). A very key point is contrast ration. 300:1 and less is poor meaning
blacks look dark grey. 700:1 and higher is good giving darker blacks and
whiter whites
DLP, LCD, and LED Technology
The technology used in projectors can generally be broken down into two types: transmissive or reflective. Because LCD projectors pass light through the LCD panels rather than bouncing it away, they are considered a transmissive medium. A DLP projector uses mirrors to direct the light in an image, so it is considered to be "reflective." The third type of projector discussed, an LED projector, is named for the light source, not the type of projection technology.
How DLP Projectors Work
First appearing on the market in the 1980s, DLP projectors rely primarily on a DLP chip (called a digital micromirror device, or DMD), comprised of up to two million tiny mirrors, no wider than one-fifth the width of a human hair. Each mirror in this chip is capable of independent adjustment, moving toward or away from the light source to create a dark or light pixel. At this point, however, the image is in grayscale. Color is fed to the DMD by a beam of light that passes through a spinning color wheel before it reaches the chip. Each segment of the color wheel delivers one color. Basic color wheels support red, blue, and green, whereas more advanced color wheels support cyan, magenta, and yellow. While these chips can create up to 16.7 million colors, a DLP projector with a three-chip architecture can deliver up to 35 trillion colors. After color reaches the DMD, the image is fed through the lens and onto the projection screen.
Advantages and Disadvantages to DLP Projectors
DLP projectors require less maintenance
than LCD projectors because they have a filter-free and sealed chip
design, which means dust can’t settle on the chip and cause an image
spot. They are effectively immune to color decay. Furthermore, they are
not subject to the misalignments that can occur in LCD projectors with a
three-panel design, which require each panel to be in perfect position
to combine the image at the proper angle. However, DLP projectors with
slower color wheels may give off a rainbow effect; flashes of color that
appear on the screen, like rainbows. Furthermore, while the chip is
sealed, other components are not, so dust can settle on the color wheel
and affect image quality. Another disadvantage may be the poor viewing
range. Most DLP projectors are not readily compatible with zoom lenses
or lens shift functions, which means they are best suited to smaller
environments.
How LCD Projectors Work
LCD projectors have been around since the 1980s, and use the same liquid crystal displays that create the images in watches and other electronic devices. Specifically, most LCD projectors use 3 LCD technology, a patented system that combines three liquid crystal displays. An image is created in a multistep process, which begins with the light source providing a beam of white light. The white light is passed to three mirrors (called dichroic mirrors) that are specially shaped to reflect only a certain wavelength of light. In this case, the mirrors reflect red, blue, and green wavelengths. Each beam of colored light is then fed to an LCD panel, which receives an electrical signal that tells it how to arrange the pixels in the display to create the image. All three LCD panels create the same image, but they have different hues because of the colored light passing through the panel. The images then combine in a prism, creating a single image with up to 16.7 million colors that is passed through the lens and projected onto the screen.Advantages and Disadvantages to LCD Projectors
LCD projectors have been around since the 1980s, and the technology is more reliable than film projectors. However, they may still require maintenance, as pixels can burn out and dust particles can interfere with image quality. On the other hand, LCD projectors have no moving parts, as DLP projectors do, and they are generally less expensive than their DLP counterparts. They also support setups in larger rooms where a greater projection distance is needed, because they are compatible with zoom lenses and lens shifts.
How LED Projectors Work
As previously stated, LED projectors are defined not by the display technology used, but the lighting. In fact, some DLP projectors with "solid-state illumination" technology are actually LED projectors. Another type of projector, the pico projector, commonly uses LED technology as well. Pico projectors are essentially handheld devices that use LCoS (liquid crystal on silicon, which is similar to an LCD panel but reflective rather than transmissive) or DLP technology. In these cases, the projector replaces the traditional lamp with longer-lasting and more efficient LEDs, colored in red, green, and blue. In DLP projectors, this also replaces the color wheel technology, instead letting the red, blue, and green LEDs shine directly on the DMD chip.
The Advantages and Disadvantages to LED Projectors
The LEDs in an LED projector have a
much longer life than traditional projector lamps, rated at 10,000 or
even 20,000 hours as opposed to 1,000 hours to 5,000 hours. As such, the
LED light source is meant to last the entire life of the projector
without ever needing to be replaced. This is a big advantage because
replacing traditional lamps can be a major expense in projector
maintenance. There is no warm-up or cool-down time needed because the
LEDs are much more energy efficient than traditional light sources, and
they are also much quieter. This reduces maintenance and operating
costs.
Factors to Consider when Buying LED, LCD, and DLP Projectors
When buying a projector, consumers should weigh the advantages of each type of device. The differences between the projectors can be summarized in the following chart:Projector Type |
Technology Type |
Light Source |
---|---|---|
DLP | Reflective | LED or standard lamp |
LCD | Transmissive | Standard lamp |
LED | Transmissive or reflective | LED |
Beyond the technology used, however, there are other significant differences. LCD projectors are typically less expensive for smaller venues, such as home theaters. They also give the user the advantage of a longer throw distance and greater zoom capability, both of which are lacking in many DLP projectors. This makes LCD projectors ideal for larger environments. However, DLP projectors do not suffer the color decay that LCD projectors do and they are easier to maintain because of their filter-free design.
DLP projectors with LED technology are even simpler because the lamp will not need to be replaced, saving time and money for users. Pico projectors that use LED technology have the same long life, but are designed to be ultra-portable, connecting to smartphones, tablets, and other mobile devices. As such, they do not offer the same high levels of brightness found in larger projectors. They typically have a brightness of less than 200 ANSI lumens, whereas larger projectors can have a brightness of 1000 ANSI lumens, up to 4500 ANSI lumens or more.
Buying LED, LCD, and DLP Projectors on eBay
When you’re ready to buy a projector, start by visiting eBay’s
Electronics department, and navigate to Computers, Tablets, &
Networking. By Selecting "All Categories" followed by Monitors,
Projectors, & Accs, you will have the option to filter results to
just Projectors.
From there, you can further filter your results by the type of
technology used, whether it is LCD, LED, or DLP. You can also narrow
down options by factors like brand, image brightness, resolution, aspect
ratio, and more. In addition to navigating the site this way, you can
simply enter a keyword, such as "DLP projector" into the search box on the eBay home page to be presented with hundreds of choices.Choosing a Seller
When shopping on eBay, you can filter your results by more than just the type of product. These options include the price range, free or expedited shipping, as well as the seller’s location. By choosing a seller who is closer, you may receive your items faster. In addition, by choosing a local merchant, you may be able to arrange to pick up the item yourself rather than having it shipped.You may also want to look for Top-rated Sellers, who have high ratings and positive feedback from shoppers who have bought from them before. eBay’s Advanced Search function lets you display results from only Top-rated Sellers. In addition, you can search for items from specific sellers if you know their ID or have added them to your "My Saved Sellers" list.
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