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A video projector takes a video signal and projects the corresponding image on a projection screen using a lens system. A bright light source is behind an image projected through a lens system. A digital video projector sends the light through a medium with a digital image rendered from a digital input source.A video projector takes a video signal and projects the corresponding image on a projection screen using a lens system. A bright light source is behind an image projected through a lens system. A digital video projector sends the light through a medium with a digital image rendered from a digital input source, unlike film, which is an analog medium.Lumens: The brightness level (measured in lumens or ANSI-Lumens) is an indication of the level of light thrown out by the projector. This is very important for business presentation projectors. '''Lumens''': The brightness level (measured in lumens or ANSI-Lumens) is an indication of the level of light thrown out by the projector. This is very important for business presentation projectors. Contrast: Ratios above 400:1 would not be perceived by the eye if viewing does not take place in a completely darkened environment. So, for the boardroom that is good enough, for the home theater 1500 or above is better.'''Contrast''': Ratios above 400:1 would not be perceived by the eye if viewing does not take place in a completely darkened environment. So, for the boardroom that is good enough, for the home theater 1500 or above is better.Resolution: SXGA (1280x1024) is currently the highest resolution available for portable projectors. Common video projector resolutions in the 4:3 aspect ratio are XGA (1024x768 pixels) and SVGA (800x600 pixels).'''Resolution''': SXGA (1280x1024) is currently the highest resolution available for portable projectors. Common video projector resolutions in the 4:3 aspect ratio are XGA (1024x768 pixels) and SVGA (800x600 pixels).3LCD or 3-LCD refers to LCD projectors using 3 LCD panels, one each for red, green, and blue.Some projectors are best for business presentations when connected to a PC while others are best for a television or movie theater type application. Now there are also cross-over' models which can handle both PowerPoint presentations in the office as well as DVD movies at home.Business presentation projector versus home theater television or movie projector application. Some projectors are best for business presentations when connected to a PC while others are best for a television or movie theater type application. Now there are also cross-over' models which can handle both PowerPoint presentations in the office as well as DVD movies at home. Most business projectors will be 4:3 screen format native with support for 16:9 wide while most home theater projectors will be 16:9 screen format native.== Projector Market Sample 2008 =={| {{table}}| align="center" style="background:#f0f0f0;"|'''price'''| align="center" style="background:#f0f0f0;"|'''model'''| align="center" style="background:#f0f0f0;"|'''model'''| align="center" style="background:#f0f0f0;"|'''type'''| align="center" style="background:#f0f0f0;"|'''use'''| align="center" style="background:#f0f0f0;"|'''resolution'''| align="center" style="background:#f0f0f0;"|'''ansi lumens'''| align="center" style="background:#f0f0f0;"|'''contrast'''| align="center" style="background:#f0f0f0;"|'''lamp hours'''| align="center" style="background:#f0f0f0;"|'''aspect'''|-| $500 ||ViewSonic PJ503D||PJ503D||DLP||business||800x600||1500||2000:1||2000||4:3|-| $560 ||EPSON S5||V11H252020||LCD||business||800x600||2000||||2000||4:3|-| $620 ||ViewSonic PJ551D||PJ551D||DLP||business||1024x768||2200||2000:1||3500||4:3|-| $680 ||EPSON S5||S5||LCD||business||800x600||2000||400:1||3000||4:3|-| $700 ||[[Epson_PowerLite_77c_Multimedia_Projector|EPSON 77c]] ||V11H254220||LCD||business||1024x768||2200||||3000||4:3|-| $850 ||BenQ W500||W500||LCD||theater||||1100||5000:1||2000||16:9|-| $900 ||MITSUBISHI HC1500||HC1500||DLP||theater||||1600||2500:1||||16:9|-| $920 ||Optoma HD72||HD72||DLP||theater||||1300||5000:1||3000||16:10|-| $1,000 ||Optoma HD70||HD70||DLP||theater||||1000||4000:1||2000||16:9|-| $1,050 ||InFocus IN36 1024 x 768||IN36||DLP||business||1024x768||3000||||2000||4:3|-| $1,200 ||NEC Display Solutions NP60||NP60||||business||1024x768||3000||1600:1||2000||4:3|-| $2,500 ||EPSON 3LCD PowerLite||V11H245120||LCD||theater||||1200||||||16:9|-| |}== Purchasing Considerations ==* Home or office: High contrast and brightness for office, 16:9 wide screen for home theater.* Room brightness: For dark rooms you require less lumens.* Operation duration: Projectors used in restaurant or taverns will be on a lot and you should look for long lamp hours and units requiring lower cost replacement lamps.* Source resolution: HDTV, DVD, VGA PC, etc.== Normal Projector Bulb Care ==You must handle the projector bulbs very carefully. Never touch the bulb with the bare hands. Skin oil will cause the bulb to burn out prematurely or explode during operation. Never turn the projector off and back on before the bulb has cooled completely to room temperature. This often takes an hour or more for the bulb to cool down completely. Failure to allow the bulb to cool down completely before powering the unit back on will shorten the bulb life or cause it to burn out. The bulb must be stone cold when you start it, or the projector will send too much voltage early in the heat-up cycle, and you'll dramatically shorten the bulb life.Some reports indicate it is not recommended to place a projector on a battery UPS. This may be due to the square wave produced by the UPS and the impact on the bulb, unconfirmed.If you consider that there are 1 year = 8765.81277 hours it puts a 3000 hour bulb life into perspective. Will you be running your projector nonstop for an entire year? If so, plan on replacing the bulb almost 3 times a year for a 3000 hour bulb.Epson seems to produce the least expensive replacement bulbs for their projectors, starting at around $180 which is below the average cost of projector bulbs, typically $350 and up. Epson models with bulbs costing around $180 are: Epson PowerLite Home 10+/PowerLite S1+, Powerlite S5 & 77C, PowerLite S1, PowerLite S3, MovieMate 25, PowerLite Home 2, and Powerlite S4 (as of 2008).