Projector Technology Explained Part I

Over the last few years, projection technology has exploded! From the early days of CRT projectors using similar tubes to those in televisions and generating 100 lumens, to projectors that can cover the face of a building, the advances have never stopped coming. Today’s market has a variety of technologies, and most people are still trying to figure out what it is that they are shopping for when they look at the options. In the next few posts I will give a quick run-down of the differences, and what to consider when choosing a projector.

Please keep in mind that this is not an exhaustive discussion of the details, but more an overview to give the average person an understanding of the basics of the technology.

First off, consider the environment. A dark room is very different from a room with full sunlight and the projector will have to be selected to handle that difference. The brighter the room, the brighter the projected image you will need to compete with that light. If you simply shop for price you are going to be very unhappy in the end, if the projector can’t handle the brightness of the space. A screen with direct sunlight is not going to compete no matter what projector you put on that screen. Shadows across the screen will also create a distraction, so having a dimmer area with even lighting (or darkness) over the screen will always yield your best results.

Next, consider your resolution. For those who are not aware of what all of those number refer to, every video image is made up of tiny dots called pixels. When a manufacturer lists resolution they are referring to the number of pixels. These counts are shown by the number of rows and columns. That means that a video image that is listed as 1024×768 will have 1,024 columns and 768 rows. This concept stays the same no matter how large or small the numbers become.

There is a never ending stream of these number combinations that keep coming to the market, but one of the things to watch is the aspect ratio.  This is another method of communicating the resolution, but is more a reference to how many units wide, compared to how many units high. So if your TV screen is 16” wide, it will also be 9” high. The irony of this is that many manufacturers (especially with TVs) refer to the diagonal measurement from top corner to the opposite bottom corner, rather than to the actual horizontal and vertical dimensions. With most equipment you can still look into the specifications and find the actual height and width, but since consumers like simplicity they are sold by diagonal measurement.


If you go shopping for a TV today you are likely to only find 16:9 models at your local store. The older technology of 4×3 has all but vanished from the consumer market, but projectors are still sold in 4:3 as well as other aspect ratios. The 4:3 projectors are typically cheaper, but remember that if you buy a 4:3 projector and send it a 16:9 signal then the available image space is going to be cropped to meet the actual image. What this equates to is the loss of the use of pixels, affecting the actual displayed revolution as well as the brightness. The same is true if you send a 4:3 signal to a 16:9 projector, so the best results that will result in the best bang for your buck is going to come from a projector that matches the signal that you are going to use and the aspect ratio of your screen.

In the next few posts I will explain more about resolution and aspect ratio, and how those relate to formats such as XGA, WXGA or HD formats. We will also discuss the differences in how these images are projected, and how blended image technology has expanded the ability to create even wider or taller images by combining projected images.

Email us for special pricing available of all Eiki projectors and Lenses

Read Part II        Read Par III          Read Part IV          Read Part V

Projector Technology Explained Part II

In part I we discussed resolution and aspect ratios. In future posts we will cover additional areas such as the different technologies used to project those images, and other advances.

The combinations of resolution and aspect ratio are summed up in specifications called the format. Designations like XGA, WXGA, WUXGA refer to these combinations. HDTV formats do this as well but include one other designation such as 1080p, 720p, 1080i and 720i references. The pixels on a screen are not changed simultaneously, but scanning across the lines and changing one pixel at a time. This happens so rapidly that the human eye does not perceive the change in this way. In the HD formats the “p” refers to a “progressive” scan that follows line by line from top to bottom. The “i” stands for “interlaced”, meaning that odd numbered lines are scanned top to bottom and then the scan starts over at the top and scans the even numbered lines. A complete cycle, regardless of the format is called a “frame” (with “interlaced” technology it is referred to in “fields”). Frames can be changed in a number of different rates (also referred to as refresh rate or expressed in Hz). This gives the illusion of motion to the human eye.

With computer images a 60Hz rate is common but some gaming systems and higher end equipment may have higher rates. Devices adjust these rates to match, using buffers either in the computer or other playback device. Different content will have different rates that may come from the same device, but the buffer will make the adjustment as needed. For example, a movie might reproduce at 24 frames per second, but a spreadsheet may produce this change only when there is a change in the content of a cell, sometimes once per second or less. A gaming system might have faster action and refresh at 120 frames per second, so a display that refreshes at 60 frames per second will discard half of that data. As long as the signal being sent is below what the display can handle then the projector will be able to handle the display rate. When the rate goes faster than the projector’s refresh rate, then the projector will have to slow it down to meet its own capabilities (if it is able to do so) which will mean the loss of this information and a reduction in the signal. A gaming system that can produce 120 frames per second may still project, but not at its full quality.

The chart below gives a breakdown of some of the more common aspect ratios and their resolutions.


Always remember that you want to find the “Native Resolution” which refers to the actual image produced by the technology in the projector. Any images sent to the projector that are not the same as the native resolution will be adjusted in some way to be able to be projected by that technology. A higher native resolution in a projector will produce a lower resolution being sent to it, but you will not be getting the full capability of the projector. A native resolution lower than what you are sending the projector may also project, but will have a degraded image from the original content. Keep in mind that when you project an image you are blowing up the size of the pixels, so every change in the image is going to show far more on a large screen than it does on your laptop monitor, or even a home TV. Also, just because a projector is advertised as being HD compatible does not mean that the native resolution of the projector is capable of HD formats. What it means is that the projector is capable of altering that signal in order to display it, but not necessarily the way it was sent to the projector.

In the next few posts we will look into the technology used by projectors to display the images.

Email us for special pricing available of all Eiki projectors and Lenses


Read Part I         Read Part III          Read Part IV            Read Part V

Projector Technology Explained Part III

In the previous posts we focused on the signals and resolutions of projectors. In this post we will turn more to how those images are projected and the light sources being used.

Many people get confused between different types of information about projection. Terms such as LCD or DLP are not referring to the same information as lamp types or laser technology. So let’s break this down into two areas: display technology and light sources.

Display technologies have changed over the years, but there are still some old technologies used for home theaters. If you have ever seen a projector with three separate lenses that appear to project three different colors then you know what I mean. What manufacturers realized is that if you split the projection signal into three different colors and project them separately, you will get a brighter and higher detailed image. This has held true as the technology advanced to newer projection methods such as LCD and DLP. While the advances in light sources and cooling technologies have made it possible to get brighter and brighter images from a single image, the best resolution vs. brightness is still achieved by splitting this up into three images.

So why don’t you see three lenses any longer? In order to simplify the use of the projectors and lower the cost of multiple lenses, the three images are now combined internally in projectors through the use of mirrors and prisms. The result is a single image coming from the lens, but internally the projector may have a single source, or three different sources. This difference is commonly referred to as “3-chip” or “single chip” technology.

The most common of the displays today are LCD (Liquid Crystal Display) and DLP (Digital Light Processing). LCD has been around for quite some time, and display devices were once made that sat on top of overhead projectors. An LCD image device similar to your laptop display or your flat screen TV was laid on top of the glass and the light from the projector would go through it the same way it would the transparencies.


This idea actually sparked a revolution to improve the brightness of overhead projectors, which would later assist in the growth in brightness of LCD projectors. Once this technology was improved to where the LCD imaging device could be shrunk down to a small size, and the brightness of the lamps could reach a high enough level, combined with cooling technologies to keep the glass in the LCD from shattering, LCD projectors were born. Early projectors were the size of some of the larger projectors on the market today (and cost about the same) but the brightness and resolutions were at a level of what you commonly find on lower end projectors today. As these areas of technology grew, the projectors shrunk in size, became brighter, and resolutions increased, but the difference in single vs. three chip still holds true today, and brightness levels are often limited on single chip compared to three chip.

Then along came TI (Texas Instruments) with an idea that the images could be projected with a more fluid approach by mounting thousands of tiny mirrors onto a single display device, where each mirror would adjust to reflect a pixel. This was dubbed the DMD (Digital Micro-mirror Device). Early models (and even some today) would have failures in those mirrors, causing individual pixels to be stuck in a single color. Over time the reliability has improved, but as the saying goes “you get what you pay for”. Cheaper single chip DLP projectors may still often have these issues after only a year or so of use. The higher level chips are far more reliable, and are used in the vast majority of cinemas today. Colors are reproduced in one of two ways: either using three different colored light sources, or by projecting through a color wheel that is synchronized with the movement of the mirrors on the chip. This often has what is commonly referred to as a “rainbow effect” where the eye perceives a rainbow type of distraction when viewing the image.

download (1)

When TI first produced the technology it was licensed to a single company, Digital Projection. This had the effect of it being slower in wide acceptance, and also slowed the advancement in how the use of the technology. Other manufacturers began the use of the technology, which has caused the advancement in its use and abilities. Typically a three chip DLP projector can produce a far brighter image than an LCD projector, and will usually produce a more blended image where the pixels are concerned.

One other technology to note is LCoS (or Liquid Crystal on Silicon). This is less common and generally only available from two manufacturers, JVC and Sony. Each has their own marketed name for the product, D-ILA from JVC, and SXRD from Sony. LCoS is essentially a highbrid between LCD and DLP, using reflective mirrors behind the LCD chip.

None of these technologies would be possible without a light source. Brightness in projection is often referred to in ANSI (American National Standards Institute) lumens. It is important to be sure that the rating you are looking at is referred to this way as it is a universal standard put out by a non-profit organization in order to provide an even playing field. Some manufacturers will skirt this definition from time to time in an effort to improve how the projector is perceived.

In Part IV we will look at lamp technologies that are used to project these images.

Email us for special pricing available of all Eiki projectors and Lenses


Read Part I        Read Part II        Read Part IV        Read Part V


Projector Technology Explained Part IV

In Part III we discussed the different methods of creating images for projection. In this post we will go over the different light sources.

None of the imaging technologies would be possible without a light source. Brightness in projection is often referred to in ANSI (American National Standards Institute) lumens. It is important to be sure that the rating you are looking at is referred to this way as it is a universal standard put out by a non-profit organization in order to provide an even playing field. Some manufacturers will skirt this definition from time to time in an effort to improve how the projector is perceived.

At present there are three different light sources being used.  Manufacturers are using lamps of various types, LEDs, and Lasers. Lamps are obviously not new. There are a wide range of types, all of which emit heat, requiring cooling systems to maintain the equipment. The downside to lamps is that they will eventually fail. One method to combat this has been to have more than one lamp in a projector so that when one fails the other continues functioning, or can be turned on without going to the projector (usually automatically). Not losing the image for the audience is often the priority, so having another lamp in place is a big bonus, but using them both together can also increase the brightness of the projected image. When you are comparing projectors it is good to keep the lamp type in mind, and also look at how many hours it is expected to last, what kind of warranty does it have, and how much does it cost to replace. Depending on your use of a projector you may need to upgrade your technology before you need to replace an old lamp, but you also may have to spend more on the lamp than to replace the projector with current technology. The other downside to a lamp is that as it ages the color temperature tends to change and the brightness goes down. It is not uncommon for good rental houses to replace a lamp at half of its lamp life in order to maintain good quality for their customers. In this case they will usually retain the old lamp as a backup for emergencies.

LED (Light Emitting Diode) technology is another area that has advanced rapidly in recent years. LEDs are not new and have been in electronics for decades, used on displays to indicate simple things like the power being on or off. When the brightness was able to be increased they began being used in light fixtures and are now being employed as a light source for some projectors. There are three big advantages: the life expectancy on them is incredibly long, they produce very little heat and since multiple LEDs are clustered to achieve brightness, the amount of power needed is far less than with traditional lamps. This is still new to the market however, and is not highly proven in the projection industry. LED projectors often cost more than their counterparts and are used in smaller, less reliable projectors. To gain brightness, most manufacturers are combining this technology with Laser technology in a sort of hybrid, which is also a newer concept and yet unproven.

Laser technology in itself however is just as it sounds. Larger scale projection manufacturers have started to use three different colored lasers as light sources for producing brighter images. The lifespan of the source is virtually unlimited and the brightness is stellar, however the cost is often stellar as well.

So in summary, here are the common options for imaging technologies and light sources. These can be combined to generate various options by a manufacturer:


In the next post we will cover lens selection, and some purchasing advice.

   Email us for special pricing available of all Eiki projectors and Lenses


Read Part I         Read Part II            Read Part III          Read Part V

Projector Technology Explained Part V

Selecting the right lens will depend on the use. Three things are most important to consider: Front or rear projection, size of screen and distance to the screen.

First a few details. The brightness of the projector will be diminished by distance. This is not only because of light loss over that distance, but the amount of glass in a lens can also reduce the amount of light reaching the screen. Better quality glass in the lens will improve the level of loss, and also will improve the ability to gain a full focus and even field. This is another one of those areas where you get what you pay for. When you buy a projector with a permanently installed lens you will need to be sure that it will be able to project the distance you need in order to fill the screen.

A rear projection setup is usually limited in throw distance (or the distance to the screen). Short throw lenses are not common in smaller projectors unless they are specifically designed for the short distance. Some installed rear projection systems are designed with a mirror or combination of mirrors. This is to provide an increase in the throw distance as the image is projected back and forth against the mirrors. Registering these images can be tricky, so you may want to consider a professional projectionist to do the job. For very short throws the lenses are typically fixed in focal length, so positioning the projector is crucial. The shortest lenses typically require the projector to be at a right angle directly out from the center of the screen, both vertically and horizontally.

Front projection can either be across a distance, from below and in front of the screen, or hanging from above and in front of the screen. The lens is chosen for the distance, and based on the size of the screen. Most specifications with show a “throw to width” factor. This refers to the distance of the screen compared to the width of the screen. If the lens shows a factor of  1.2~1.8, then to get the closest distance to the screen you multiply the width of the screen by 1.2, and to get the maximum distance multiply 1.8 by the width of the screen. So if you have a 10’ wide screen then this lens would need to be between 12’ (10 x 1.2) and 18’ (10 x 1.8). This distance is from the front of the lens to the screen surface.

One of the leading projector manufacturers on the professional market is Eiki. Below is an example of available lenses and their specifications for an Eiki EIP-UJT100, which is a 14,000 Lumen projector with a 1900 x 1200 resolution. This projector is a higher end unit that is currently known for being one of the best bangs for the buck on the market. You will notice that there are a range of lens options that cover almost any installation situation; however the lens choice will often drive the overall cost of any projector. In the case of Eiki they offer an installation package that includes the projector, lens, spare lamps and a mount to hang the projector. For current pricing on this package or other projector options, contact us and we can work through your specifics.


You will note that there is a lens that is marked as a “standard lens”. This is typically the lowest cost lens, and if a projector comes with an included lens but has optional lenses, the standard lens is the one included.

On this chart you will see the list pricing for these items. As is the case with most anything in the retail world, the list price is the highest price that should be expected to be paid for an item. With equipment like this, most manufacturers hold their dealers to another standard, called MAP or Minimum Advertised Pricing. While it is not legal for them to set a price at which an item is required to be sold, they can require that the advertised price be limited to a certain level. Most often this will be the lowest price that you will find something available for sale on the internet, but not the lowest price available. Often you will have to speak to the dealer to find out the best price that they will offer.

These posts have not been an exhaustive list of information about this technology, but we like to inform our customers as best as possible when making a decision such as this. Obviously we have just scratched the surface in some ways, so we offer a service to help you in designing, contracting and/or installing systems. Typically this service will save you more money than you will spend with us, and if you utilize our services on the full project, then we can often credit all or part of the fee toward the purchase of your equipment.

 Contact us for more information

Email us for special pricing available of all Eiki projectors and Lenses

Read Part I          Read Part II         Read Par III          Read Part IV