What is a Projector? What to Look for in a Projector?

Home projectors are fast becoming the new normal in the high-definition or HD era. Digital video projectors are much more common nowadays for home use because home cinemas or theaters have become far more ubiquitous in 2020, especially in the current coronavirus or Covid-19 reality we face where everyone has ended up stuck in their homes due to the worldwide lockdown used to flatten the curve.

What is a Projector?

A projector is an optical device capable of “projecting” or extending its light outward or beyond itself in order to form an image, video, or display unto a projection screen. The modern digital projector is capable of the reproduction of an image or a series of images on a surface. The projector can blow up a small image to huge proportions on a blank screen so that more people can view a movie or TV series as well as a videogame in full glory and greater detail.

History of the Projector

So who invented the modern projector? Before that, the concept of projecting light over an image to make it appear bigger on a larger surface was present from thousands of years, ranging from prehistoric shadow plays to what’s known as the Chinese magic mirror. There’s also a device known as the camera obscura (pinhole camera) that deployed the same principles used in modern projectors, but the image is upside down and uses a dark room to work.

Video Source By Youtube – The Chinese magic mirror

The magic lantern was invented in 1659 by Christian Huygens. It uses a concave mirror to direct light from a lamp to a glass slide with an image that’s then projected to a screen using a focusing lens. In 1756, Leonhard Euler made the episcope or opaque projector that uses a system of prisms and mirrors to project an image. These early pre-computer projectors were mostly used to entertain audiences or for lectures. From there, around the 1940s to 1960s, the slide projector was developed that made use of a series of 35-millimeter slides for projection.

01 opaque projector
Opaque projector – Image source By Tarleton


Overhead projectors are slide projector variants that used a halogen bulb and a glass plate you’re supposed to put the transparent page over for projection purposes. Then computer technology advanced enough to allow use of digital projectors from the 1970s to the 1990s. Projectors in the 2000s to 2010s are more viable for home use and resolutions have increased greatly enough to justify getting a projector.

Overhead projectors
Overhead projector – Image Source by Nicole C. Baratta


What Are the Parts of a Projector?

A typical modern projector is made up of the following parts.


  • Lens: The lens of the projector is what beams or projects the image towards a given screen. Some lenses are of the zoom or telescopic variety that enables you to do lens zoom on the image, making it as large or as small as you want without physically moving the projector.


  • Projection Lamp: A lamp that’s either of the halogen or LED (light-emitting diode) variety assists in the projection of the image. How bright the projector is depends on how powerful or how many lumens the projector lamp has.


  • HDMI and USB Connectors: The HDMI connectors are obvious the HDMI output ports of the projector that allow you to connect source media like Blu-Ray and DVD players as well as game consoles unto it. The USB connectors are usually for flash drives or to share power with certain mobile devices. Some projectors have extra A/V ports for composite and component cables as well.
03 the Parts of a Projector
The Parts of a Projector – Image source by Marty Nelson
  •  Power Connector: This is where you’re supposed to plug in the cable that enables your projector to plug into the power socket.
  • Speaker: Some projectors come with their own speaker that you can bypass for a Bluetooth speaker, a wired soundbar, or a home cinema sound system.
  • Control Panel: Speaking of which, aside from the remote or app you use with your phone, the projector should have a control panel that might be composed of a series of buttons you could press or an LCD touchscreen you can manipulate depending on how high-tech your projector is.
  • Remote Control: Remote controls, also known as remote receivers, enable you to control your projector from afar without having to push any buttons or touch the screen of your projector control panel.
  • LAN Connector: A separate LAN connector is available in case you want a wired Internet connection for your projector using LAN cables instead of depending on its Wi-Fi connection to your home Internet router.
  • The Fan, Intake Vents, and Exhaust Vents: Inside the projector is a fan that cools it down as you use it with the hot LED lamp. It sucks up the air around the device using the intake vents then dissipates the heat using the exhaust vents for efficient cooling action.

How a Projector Works

A projector works by shining light through a small transparent lens. There are multiple projector technologies available that enable you to project the digital image from your source media in a direct manner, such as using lasers instead of LEDs. The projector that replaced the slideshow projector back in the 1990s to 2000s—the digital video projector—is a culmination of all the technologies dating back to the camera obscura and magic lanterns of yesteryear to the movie projectors and slide projectors of the early 20th Century.

04 How a Projector Works
Laser projector – Image source by Sven vB


The Liquid Crystal Display (LCD) projector was the projector type that dominated the video projector used mainly for business presentations and computer monitor mirroring. They were eventually also used as television alternatives as the tech became more common and available. You now have the mirror-based, prism-like Digital Light Processing (DLP) projectors as well as the LCD/DLP hybrid known as Liquid Crystal on Silicon (LCoS) projectors that mix LCD tech with DLP prisms together.

Types of projector

Here are the most common types of projectors available according to their commercial availability. You buy them in accordance to your needs and what type of customer you are, whether you’re a homeowner with a home cinema or a business/school with a conference room.

  • Home Theater Projectors: As the concept of the home theater became more and more popular not only among the rich elite upper class but also the upper-middle-class suburbia, so too did the home theater projectors. They really came on their own around the late 2000s and early 2010s when HDTVs (high definition television) started replacing the bulky CRT (cathode-ray tube) TVs of yore and their square 4:3 aspect ratio. Out from the PC-compatible business projectors came forth the made-for-HDTV home theater projectors with their 1080p full HD resolutions and HDMI connections. They were also available with the 16:9 aspect ratio to boot.
Home Theater Projectors
Home Theater Projectors – Image source by Area 51
  • Business Projectors: Business projectors are projectors used in businesses for presentation purposes and they mostly connect to laptops and desktop PCs to mirror interfaces and allow access to programs like Microsoft PowerPoint or Excel. They can also be used as teaching aids as needed. Specs-wise, they differ from their home theater counterparts by featuring a different aspect ratio (from 4:3 to 16:10) and more resolution options than the 720p and 1080p options of standard home theater projectors. They’re mostly compatible to computers rather than HDTVs. They had more resolution sizes because they catered to different notebook PC and workstation models.
Business Projectors
Business Projectors – Image source by Phil Sexton
  • Short Throw and Long Throw Projectors: Throw distance is the distance from the projector to the screen. There are projectors with short throw distance and long throw distance. A short-throw or short-throw projector is one you can place up close to the projection screen and still end up filling it up. Standard ceiling-mounted or backroom projectors might have longer throw distances of many feet that require you to place the device as far as the back of the room if needed. A short-throw projector is handy due to its close screen proximity.
07 Short Throw and Long Throw Projectors
Short Throw and Long Throw Projectors – Image source by CinemaRooms


Projector Features or Specs

A projector typically has the following specifications or features that you should watch out for.

  • Resolution: This refers to how big the projected image you’re looking at is. Some projectors have standard 480p or 480i native resolution that can be blown up to 1080p and 1920 x 1080 pixels or have a native 1080p resolution from the get-go. The bigger the native resolution the better and more detailed the results. You can go up to 4K or 4096p if you want.


  • Aspect Ratio: Long story short, aspect ratio refers to the ratio between the height and length of the screen. For example, the 4:3 aspect ratio of CRT TVs have a square shape wherein for every 4 inches of length there’s 3 inches of height in screen-size terms. HDTVs have a 16:9 aspect ratio and widescreen PCs used for slideshow presentations instead feature 16:10.


  • Brightness: How bright the projector is. Brightness is measured in lumens. Certain projectors have low brightness so you can only view them in low-light or no ambient light (no daylight or light bulbs nearby) situations. Others, you can view in daylight or outdoors, such as in the case of backyard movie nights. You need at least 2,500 lumens to project in daylight.
Projector Features or Specs
Projector Features or Specs – Image source by Corporate AV Hire


  • Contrast Ratio: The amount of difference between the brightest and darkest areas of a picture. It’s how bright the light parts are compared to the shadows. How good the contrast ratio is will determine how easy it is for you to see fine details like lettered text and surface texture. If your projector has poor contrast ratio, the image comes off as muddy, blurry, or gray.


  • Throw Ratio: Throw ratio refers to how wide or large the image will end up depending on how far you place the projector. As discussed earlier, different projectors have different throw ratios. Buy projectors in accordance to how far back of the room you want to place it, even if you intend to put it on a ceiling mount. For example, a 2.4:1 throw ratio means you need 24 feet of space to project a 10-foot image on a big screen.


  • Lens Zoom: Lens zoom is a way for you to manipulate or adjust your projector’s picture or projection in case the image is too large or too small for it. Normally, you do your adjusting by moving the projector around until it’s at the right distance in accordance to its throw ratio. However, if you can’t do that because you got a smaller screen or the ceiling mount has already been installed, you can use the projector’s lens zoom feature to simply shrink or stretch the projection at will.


  • Keystone Correction: When you project an image or video at an angle, the result is usually a keystone-like trapezoid. If you can’t move the projector from its position, you can “correct” the trapezoidal shape by using the keystone correction feature of your projector if it has one. Fair warning though—the more keystone correction you do, the more the resulting projection’s resolution will be affected, resulting in jagged lines, pixilation, or “artifacts” all over the digital image.


Benefits of Projector

The benefits of a projector are myriad and undeniable. There are things you can do with

  • Value: The quality should match the price. At the very least, you should get a projector that gives you more quality or features for its cost so that you can end up maximizing your investment relative to your budget.


  • Portability: A projector, even the biggest ones the size of a printer, are relatively portable and compact. There exist pico or pocket projectors that are the size of a smartphone or external HDD, in fact. They’re mostly short-throw projectors as well due to their size. Get a projector size that makes sense for your circumstances.


  • Eye Comfort: The brightness of the projector should be just right to ensure that you’re seeing the resulting image in a way that doesn’t strain your eyes. The blue light of a projector doesn’t cause as much eye strain as the blue light from an HDTV exactly because you’re seeing a reflected or projected image instead of watching something directly on a lighted screen.


  • Huge Images: The bigger the image the more detail you’ll see once that image is projected. Other factors such as resolution or how many pixels are in the image as well as contrast ratio and aspect ratio can affect the quality of the image, but for most people any projector is beneficial to have due to the bigness of its projections.


  • Customizable Image Size: Speaking of which, unlike HDTVs and computer monitors, it’s possible for you to customize the image size of the projection or image you’re looking at by fiddling at the settings or the controls of the device. You can use lens zoom or keystone correction to fix projections aimed at an angle or at the wrong throw ratio. If you’re projecting on a blank wall, you can literally make the screen any size or aspect ratio you want, even.
Benefits of Projector
Benefits of Projector – Image source by Danny Choo


What to Look for in a Projector

When picking a projector, it’s all about determining your specific goals or applications, the price you can afford, the available devices you have to accompany it like a sound system, BD player, or Wi-Fi, and so forth. Your budget is your best bet in making a shortlist of viable projectors to buy. You can further narrow things down by your personal preferences, whether you’re willing to splurge for a specific projector-type, or if you need a low-latency projector for online first-person shooter gaming purposes. Your financial circumstances and personal tastes should serve as your guide to getting the right projector for you.

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Regardless, you have more home projector units now than there were in the early 2010s or the 2000s, where the norm was more about business or school projectors used to do digital presentations on Microsoft PowerPoint or Excel on than anything else. However, technology has advanced greatly from 10 to 20 years ago.

10 What to Look for in a Projector
Looking for in a Projector – Image source by jack Smit


Projector FAQ

Here are the most frequently asked questions regarding projectors that you should keep in mind.

  • What Feature Is Important in Projectors? It’s hard to pinpoint what one feature is most important when buying a projector, but usually it boils down to image quality. This is an umbrella term that takes into consideration things like resolution (1080p or 4K), contrast (how stark the difference the whites and blacks of your projector are to ensure better image clarity), and brightness (how many lumens your projector has and if it’s enough lumens to ensure that you can see the projection even in ambient light on top of in the darkness).


  • What is the principle of a video projector? The principle of a video projector is that it’s a device designed to project a 2D or 2-dimensional image unto an object or surface. It creates images by mirror or by polarized glass that lets certain light come through and other types of light blocked. This results in the digital reproduction of a source media’s image, whether it’s a high-res game from a game console or a 4K masterpiece on Blu-Ray disc. Motion picture projectors could also use shutters for light blockage that moves out of the way from time to time to flash the light only when a frame is lined up.


  • What is the purpose of a projector? A projector can be used for home entertainment as an HDTV alternative. They emerged originally as projectors used by businesses to do presentations on PC as well as educational purposes. As both the computers and the projectors became more sophisticated, they eventually found their way to being used as digital alternatives to film projectors, since they can mirror PC displays and computers can play movies and TV shows themselves. When television became smart TVs and HDTVs or more computerized and advanced like smartphones, that’s when media became high-quality enough to justify projecting them on a projector.
the purpose of projector
The purpose of projector – Image source by NCAA


  • What are the advantages of projectors for home entertainment? As far as home entertainment is concerned, projectors have a myriad of advantages. For one thing, they’re better at projecting 4K resolution videogames and movies due to how many pixels are present at those resolutions. You can fit millions of more pixels on a big projection screen compared to an allegedly 4K HDTV that has a much smaller screen, which defeats the purpose of viewing something in 4K. Additionally, projectors are compact and portable with the ability to adjust or customize your image size to whichever size you want depending on the projector screen size and the source media.


  • What are the reasons why your office needs a projector? Your office might need a projector if it requires it for presentation purposes. Even to this day in the 2020s, many an office still use projectors for their original intended purpose of doubling as computer monitors to enable widescreen views of Microsoft PowerPoint or some other slideshow presentation program. They’re supposed to be the more advanced version of the original film slide projector of yore, after all. Therefore, it makes sense that they’re mostly used as presentation or slideshow displays as the computerized version of the slide projector.


  • What are the uses of the projector in education? Projectors have been used for instruction and education for far longer than the advent of the slide and overhead projector. The original pre-computer projectors could mostly make projections of still images instead of moving ones like the film projector. Therefore, they were mostly used in classrooms with loads of students in order to present lessons and pictures being discussed in such lessons, as in the case of Leonhard Euler’s opaque projector or Christian Huygen’s magic lantern. From the overhead projector that projects clear plastic sheets with words printed on them to modern projectors showing notes in slideshow format, projectors are educational as well.



Projectors have evolved through the decades, from merely being used for slideshows in darkrooms or for commercial cinemas all the way to businesses for presentations and homes as TV alternatives. They were originally camera obscura and Chinese magic mirrors. Their lineage can even be traced all the way back to prehistoric shadow plays thousands of years ago, long before humans could even conceive what a movie is supposed to be. The main appeal of projectors nowadays is that you can view movies in a cinema-like manner, using screens much bigger than your normal HDTVs at a relatively affordable price.


James Core

I love my projector system and I am here to help you find the right projector for your needs.

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