See Projectors under computing for general information.

There are several kinds of projectors. Some work better for specific purposes:
- Use: Business Presentations (data), Home Theater (video), Photos (images) or Gameplay
- Technology: LCD, DLP, and LCOS (see below)
- Brightness:
- Throw Distance: how close to the screen you can place the projector
- Portability

The hot new technologies in 2010 were.
1. Pocket projectors - Small (fit in your pocket) lower resolution models you can connect to your iPhone or tablet.
2. Interactive projectors - Use a light pen for interactive whiteboard capability. You can draw, point and click with the pen.
They are $1,500 - $2,000 3. Game playing models designed to be used the Wii, PS3 or Xbox. e.g. Epson GT720 WXGA $800

SVGA (800x600) and WVGA (854x480) are still available and fine for powerpoint presentations or slide shows.
The Somerset County Photography club just (Nov. 2011) got a XGA (1024x768) projector which is their standart format for photo contests. This format is good for slide shows and power point presentations.
Now, projectors for home theater high def movies are becoming more popular. These use HD 720p (1280x720) and FHD 1080p (1920x1080) resolution.
I am referring to what manufacturers call native resolution, the pixels you see on the screen. They also list maximum resolution, which what they will accept on input. Most XGA above projectors will accept FHD (1080p) input.

In May 2016 my computer club got a InFocus 2128HDa (1080P) $782 4.4 (21)
InFocus IN2128HDa Review & Rating | 3.5

Projectors will give you a larger image and are more portable than a flat panel display, but they are not as bright (15-20 ftL (foot Lamberts) for a projector vs 37 ftL for a flat panel display) so require a darker room.

A sample of the 50 or more available.
2015 list:
Compare Projectors

Dec 2011 - High Def 720p or 1080p
Model Cost Lum-
CR cnet/
to screen
zoom Lamp/
wght spea-
View-Sonic PJD5523w $450 2700 3000 1280x800 3.5-5 DLP 5-26 1.2  
View-Sonic PJD6553w $650 3500 4000 1280x800 4 DLP 4-33 1.3  
Epson PowerLite 1761W $650 2600 2000 1280x800 4.5 EC 3 LCD 2.4-28 1.2 wireless 4,000  
Optoma HD66 $700 2500   1280x800 56   DLP 12.5-13.5 1.1 P-VIP 3,000 5  
Optoma HD6700 $825 1800 4000 1280 x 720 71   DLP            
InFocus IN76 $1,200 1000 3000 1280 x 720   3.5 DLP       3,000 9.3  
Casio XJ-A245VJ portable $1,300 2500 1800 1280 x 720     DLP   2X LED 20,000 5 1W
Casio XJ-A255VJ portable $1,500 3000 1800 1280 x 720     DLP   2X LED 20,000 5 1W
Casio XJ-M240J $1,000 2500 1800 1280 x 720     DLP   1.5X LED 20,000 8.6 5W
Casio XJ-M250 $1,200 3000 180 1280x800     DLP 4-14 1.5X Laser and LED hybrid 20,000 8.6
Casio XJ-A250 $1,200 3000 1800 1280x800     DLP 4-16 2X Laser and LED hybrid 20,000 5 1W
FHD 1080P
JVC DLA-HD250 $2,850 1000 25,000 1920x1080 86   LCOS 10.5-20.5 2 UHP   24 lb  
Sony Bravia VPL-HW15 $3,000 1000 60,000 1920x1080 80   LCOS          
Epson PowerLite Home Cinema 8500UB $2,200     1920x1080 79   LCD          
Epson PowerLite Home Cinema 8350 $1,100 2000 50,000 1920x1080 72   LCD 11-22       16  
Optoma HD20 $1,000 1700 4000 1920x1080 68   DLP 12-14.5          
Optoma HD22 $560 1900 5000 1920x1080   DLP 5-32 1.2 230W P-VIP      
Vivitek H1081 $950     1920x1080 64   DLP 12-15          
Vivitek H1080FD $800-1000 1800 4000 1920x1080 DLP 12-15          
Mitsubishi HC4000 $1,300 1300 4000 1920x1080 78   DLP 11-16 1.5   5000 8  
Resolution - Native - Actual pixels it can produce; Maximum - Maximum input data format it will handle. This will be reduced to produce the output at the lower resolution.

CR - Consumer Reports Score
cnet - CNET editors review

If you want to want to watch videos in a bright room the Wolf Cinema DCX-1000i with a 1,000-watt xenon lamp for $85,000 puts out 5,500 lumens.

Lamp Life - Projector lamps usually don't burn out the way light bulbs do. They gradually get dimmer and dimmer until they go out. If you haven't replaced your lamp in awhile, you'll be surprised how much brighter your "old" projector can look with a new lamp!

Dec 2010
Mfg. Line Model Type Resolution Brightness Contrast Lamp Life (hrs) size cost comments
Optima PK201 DLP-LED WVGA 20 2000:1 20,000 4.7x2.7.1.4 $300
Optima PK301 DLP-LED WVGA 50 2000:1 20,000 4.7x2.7.1.4 $400 PC mag Editors choice
Optima DX606v DLP XGA 2200 2000:1 2000/3000 10.2x7.4x2.8 $500 no HDMI
Epson PowerLite 1775W LCD WXGA 3000 2000:1 4000 11.5x8.3x1.7 $1,200 Wireless
Epson PowerLite 1260 LCD WXGA 2600 2000:1 4000 11.6x9x3.1 $750
Epson PowerLite 92 LCD XGA 2600 2000:1 4000 11.6x9x3.1 $650
BenQ Joybee GP1 DLP-LED 858x600 100 20,000 5.4x4.7x2.2 $500 PC Mag editors choice
Other popular manufacturers: Dell, InFocus, Casio

Most have VGA and HDMI inputs

Type  Pixels  Aspect ratio (16:9 - High Definition Std)
Computer Monitors
SVGA  800x600   4:3 1.33:1
WVGA  854x480  16:9 1.78:1
XGA   1024x768  4:3 1.33:1
WXGA  1366x768  16:9 1.78  *
WXGA  1280x768  5:3 1.66:1 *
WXGA  1280x800  16:10 1.60:1 (WXGA 60-1)
WXGA+ 1440x900  16:10
SXGA  1280x1024 5:4 1.25:1
SXGA+ 1400x1050 4:3
SXGA- 1280x960  4:3

* WXGA Wide Extended Graphics Array is
a set of non standard resolutions
1280x800 16:10 was common for laptops but 
1366x768 16:9, common on LCD TVs, is more common now;
It works better for consumer entertainment with HD 720p

Video resolution standards

WSXGA 1600x1024 25:16 1.56:1
WSXGA+1680x1050 8:5
UXGA  1600x1200 4:3
WUXGA 1920x1200 8:5
WQXGA 2560x1600 8:5
QWXGA 2048x1152 16:9
WQHD  2560x1440 16:9

SD     720x480   4:3 (pixels are rectangular 10:11)
HD    1280x720   720p  16:9
FHD   1920x1080  Full High Def 1080p 16:9
SLR  3:2
compact digital 4:3

DLP vs LCD vs LCoS:
DLP (Digital Light Processing) uses tiny mirrors, one for each pixel, to reflect light. DLP modulates the image by tilting the mirrors either into or away from the lens path. It is therefore a "reflective" technology. This chip is produced exclusively by Texas Instruments and is called a DMD (Digital Micromirror Device) chip.

LCD (Liquid Crystal Display) uses liquid crystals, one for each pixel, on glass panels. Light passes through these LCD (Liquid crystal Display) panels on the way to the lens and is modulated by the liquid crystals as it passes. Thus it is a "transmissive" technology.

LCoS (Liquid crystal on silicon) combines these two ideas. (Sony's SXRD and JVC's HD-ILA are LCOS variants) It is a reflective technology that uses liquid crystals instead of individual mirrors. In LCOS, liquid crystals are applied to a reflective mirror substrate. As the liquid crystals open and close, the light is either reflected from the mirror below, or blocked. This modulates the light and creates the image.
LCoS generally has the best contrast.


LCD and LCOS have 3 chips, red, green and blue.
DLP can have 1 or 3 chips. 1-chip DLP's have a spinning wheel with the three colors and one DLP chip. They can be prone to rainbows or color fringing, but it is minimal in current versions and may not be visible to many.

Trueness of color is also one of the significant differences between two major types of projectors: LCD, for "Liquid Crystal Display", or DLP, for "Digital Light Processing". DLP projectors tend to be very bright with higher contrast ratios, and they have become popular for smaller, lighter, "ultra-portable" projectors. To produce a color image, DLP projectors reflect a light through a rapidly spinning color wheel, which can lead to a slight flickering of color and sometimes to an unnatural color appearance. LCD projectors often do slightly better with color, but they tend to shift the color a bit towards the blue range, and some significantly so. DLP projectors also run very hot, which can be a problem for a portable projector in particular.
Due to the relatively high switching speed of DLP (up to 1,000 times faster than some competing technologies), DLP-based systems can more accurately display dynamic images (e.g. sporting events), while technologies with slower response times may produce some image smearing. For more information about DLP, see:

Lumens and Contrast Ratio:
Brightness vs Contrast in Home Theater Projectors at says,
"With business projectors, lumen output is of primary importance, and contrast is a secondary concern. Home theater projectors are the exact opposite. "
"When it comes to home theater projectors, brighter IS DEFINITELY NOT BETTER. What you want is a projector that produces enough light to fill your screen with good contrast, but not so bright that it creates eye fatigue when viewed for any length of time."
"Whatever you do, don't make any assumptions about a projector's brightness based on its ANSI lumen rating. Some models have video optimization incorporated into their ratings and others do not. That means there are projectors out there which are officially rated at 700 ANSI lumens that are actually brighter than models rated at 1500 ANSI lumens. So the spec sheets, as far as lumen ratings are concerned, tend to be meaningless for home theater. "

Higher lumens allow you to see a picture with more ambient light. i.e. you don't have to have a very dark viewing room.
High lumens and low contrast ratio will have a poor black level (very grey). It will also have trouble showing shadow detail, and as the image goes towards black (grey), the colours desaturate.

A high contrast projector produces a picture with a rich, dynamic look, good shadow definition, and deep color saturation. Contrast gives "depth" to video images.

The contrast ratios noted on a projector's spec sheet can be reported in one of two ways. If it just says "Contrast," it usually indicates On/Off contrast, which is the ratio of the whitest white and the darkest black that the projector is capable of producing. If it says "ANSI contrast," the ratio has been determined by displaying a checkerboard pattern of white and black squares and measuring the relative brightness of each. On/Off contrast is always a larger number, and more typically listed on projector spec sheets, but ANSI contrast is a more accurate representation of what your projector is actually capable of during normal use.
There are many entry-level projectors rated at 3000:1 on/off contrast. 3000:1 is typically enough to give satisfying black levels and color saturation, enough to avoid the sense of flatness or muddiness in a picture.
50,000:1 is the the best you can get in a high end system.

ATSC - Advanced Television Standards Committee

Anamorphic lens - An add on ($3,000-$10,000) that allows super wide 2.3:1 displays.

Auto iris - Enhances contrast by closing down lens in dim scenes.

DLP - Digital Light Processing (see above)

E-TORL - Epson Twin Optimized Reflection Lamp. Minimizes both light defraction and light leakage, providing you with up to 50 percent more lamp life.

Fl or ftL- Foot Lamberts - See PFL below. Takes the screen into account and measures the total light that is being reflected back toward the audience.
A common misconception is that a projector with twice the foot-Lamberts of another projector will be twice as bright. While it is true that a light meter will detect it as twice as bright, your eye will not. The perceived brightness will increase by about 50%. It will not double because the human eye has a logarithmic respond to light.

Frame rate - frames/sec
The video on most Blu-ray discs is encoded at film's native rate of 24 frames per second, or 1080p24.
1080p TVs display video at 60 frames per second, so this format is often referred to as 1080p60
Projectors with 120 Hz and 240 Hz refresh rates reduces LCD motion blur and motion looks smoother and more fluid, with less smearing.

Gamma - Relationship between input video voltage and output brightness. Determines how mid-tones appear as eye sensitivity is non-linear and display devices use different methods to account for this as well as their own display characteristics.

IRE brightness - Institute of Radio Engineers brightness measurement. Absolute black is 0 IRE, and peak white is 100 IRE.

LCD - Liquid Crystal Display - (see above)

LCoS - Liquid crystal on silicon (see above)

LHP - LED High Power lamp

Lumens - Light energy output by the projector.

PFL - Projector Screen Foot Lamberts (Fl). Convert the lumens produced by the projector to PFL using the following formula:
  PFL = (Projector Lumens / Screen Area in Sq.Ft.) X Screen Gain

TEDR - Total Environmental Dynamic Range. Describes the actual contrast ratio achieved in a venue.
TEDR = Projector Screen Brightness / (Projector Screen Black Level + Ambient Light reflected by the Screen)

THX - THX is mainly a quality assurance system. THX is a trade name of a high-fidelity audio/visual reproduction standard for movie theaters, screening rooms, home theaters, computer speakers, gaming consoles, and car audio systems. They certify movie theaters, home theater components, video displays and other A/V systems for quality.

UHE - Ultra High Efficiency lamp uses a shorter arc length to achieve higher efficiency

Tech Tip at
Glossary at
HDTV Glossary

Projectors vs. TVs: Giant-screen pros and cons - CNET, 2013
The 10 Best Projectors of 2015 |
Compare Projectors | Projector Screens
  Home Theater systems and Media Rooms
Video resolution standards
Projectors under computing
Projector Reviews | Home Theater
Projectors - Projector Reviews
Projector Reviews |
Top 10 Best Projectors |
Home Theater Video Systems at
Technology of Home Theater Projectors
LCoS, HD-ILA, SXRD at Home Theater Network
Projection Calculator Classic - Throw Distance and Screen Size
Light up a Room at
Choosing LCD Projector
Smart Computing Article - Choosing a Business Projector

last updated 15 Feb 2012