Overview of the Best Digital Projectors Features
A Quick Run Down
With the ever growing demand for home theater projector systems, we have created this helpful guideline so you will know what are some of the best digital projector features are and what they mean.
If your looking to know how to buy a good LCD projector or how to buy a home theater projector these listed features are worth taking a read over.
Brightness
Resolution
Contrast Ratio
Aspect Ratio
Weight
Data and Video Inputs/Outputs
Audio Support (Speakers)
Keystone Correction
Lens Shift
Document Camera
Lamp hours (half life)
LCD or DLP?
Price!
Brightness[ top ]
Today’s projectors come in a wide assortment of light outputs, which are measured in ANSI lumes typically referred to as “lumens”. The higher the ANSI lumen rating the brighter the projector will be. Also a higher lumen rating also drives an increase in the unit cost. So expect to pay more for a projector that is rated at 3000 lumens versus 1000 lumens. Depending on the end application the projector is to be used for (home entertainment or commercial) there is no absolute formula to determine exact output required, there are though certain factors and guidelines available to make sure your projector is neither too bright (colors become washed out) nor too dim (picture clarity).
TIP: As projector technology advances brightness is becoming less important. So please keep this in mind if you wish to know how to buy home theater projector.
We have a detailed Projector Brightness Guide »
Resolution[ top ]
A projectors resolution (or, its “native resolution”) is simply the number of pixels that it has available to create an image. The higher the resolution of a projector, the more pixels it has.
Projector resolutions is designated with two numbers, such as “1280×720″. The first number indicates how many pixels there are in each horizontal row, and the second number is how many pixels make up each vertical column. If you were to multiply the two numbers, you would end up with the total number of pixels for the projector device.
Similar to brightness, the higher the resolution, the more the projector will cost. The main advantage of higher resolution projectors are that they can display more detail in the picture (assuming the video signal has the detail in it). The other advantage is it reduces or eliminates the visibility of the pixel structure. Both of these are highly desirable in a good home theater system and in the boardroom. The advantage of a low resolution projector is that they have come down in price in the last few years so you can get into a large screen home theater with a small investment.
We have a detailed Projector Resolution Guide »
Contrast Ratio[ top ]
It is a measure of a display system, defined as the ratio of luminosity of the brightest color (white) to that of the darkest color (black) that the system is capable of producing. A high contrast ratio is a desired aspect of any projector as the higher the ratio the sharper the image. At its basic it is a measure of the difference between the black and white areas of an image.
Contrast ratios vary by projector type, for example, LCD versus DLP, but a good guideline is to choose a projector with a contrast ratio of 400:1 to get the best video image.
We have a detailed Projector Contrast Ratio Guide »
Aspect Ratio[ top ]
16:9 - For wide screen images, this aspect ratio gives viewers the full picture of movies and broadcasts, about one-third wider than standard displays. It is the format for HDTV video and some SDTV video.
5:4 - This is the display aspect ratio for images with SXGA resolution. Wide-screen images will appear cropped at this ratio.
<4:3 - This is the standard display aspect ratio for TV, as well for images with VGA, SVGA, XGA, or UXGA resolution. Wide screen images will appear cropped at this aspect ratio.
We have a detailed Projector Aspect Ratio Guide ».
Weight and Portability[ top ]
If you plan on taking your projector on the road or if your on the move, you’ll appreciate having a projector that’s as portable as your budget permits. Luckily, today’s projectors are smaller than ever, with the lightest coming in around 0.9kgs (2 lbs) and being easy to carry over the shoulders. However though, the desktop models still have more features and represent better value if the projector is going to stay in the same location.
We have a detailed Projector Projector Weight & Portability Guide ».
Data and Video Inputs/Outputs[ top ]
Connectivity and compatibility also factor into getting the sharpest and clearest images. In general the more input/output ports the projector has the more expensive it will be. If you know what kind of devices you will be using in conjunction with your projector, you will want to look for projectors that offer the same connectivity as your source player and look for a projector that offers both auto-signal detection and plug and play capability as this will reduce set-up times for your presentation.
You should do your best to think ahead and make sure any projector you buy can handle a wide range of current and future options, including digital video and HDTV signals.
We have a detailed Projector Video & Data Inputs/Outputs Guide ».
Audio Support (Built in Speakers)[ top ]
If your most likely going to be projecting multimedia with sound, you have the option of either connecting your PC (personal computer) or video source to an amplifier, or if this is too much you can use the internal speaker (not available on all makes and models). The industry standard for most projectors is 1 watt mono as they are primarily used as display devices. This wattage will provide enough volume for a room of 20 to 30 people to hear if the audio is speech. If you want something with a little more impact, either look for a projector with a 2.5 - 3 watt speaker or consider the amplifier solution.
Surprisingly the built in speakers are very good for their size on most projectors so it does give you the option of taking your projector with you on vacation where you have lots of downtime to catch up on.
We have a detailed Projector Audio Support & Fan Noise Guide ».
Digital Keystone Correction[ top ]
“Keystoning” occurs when a projector is aligned non-perpendicularly to a screen, or when the projection screen has an angled surface. The image that results from one of these types of misalignments will look trapezoidal rather than square/rectangular. A distorted image as such is a major distraction to the viewer. Sometimes do to the nature of the room there is no other way to mount or place the projector. This is where keystone correction comes into play to counteract this effect by digitally compressing the image at the top or bottom resulting in a squarer, more professional looking screen image.
Keystone correction counteracts this effect by digitally compressing the image either horizontally or vertically, resulting in a square image. Today’s projectors come standard with either a manual or digital keystone correction feature.
We have a detailed Projector Digital Keystone Correction Guide ».
Lens Shift[ top ]
Lens shift allows space with the projector housing to move the lens itself either up and down or left and right. This adjustment can be made either manually with a dial or joystick, or mechanically using the menu buttons. This extra allowance of space with the projector to reposition the lens means greater leeway in the placement of the projector.
You might be thinking to yourself, “this sounds similar to keystone correction?”, and “what is better of the two?”. In general lens shift is the better of the two and normally only found on the higher priced projectors. Keystone correction accomplishes the correction by digitally compressing the image which can cause noticeable artifacts along the corrected portion of the image. Lens shift on the other hand accomplishes the correction by shifting the lens. In a permanent mount installation it is best to look for a projector with lens shift.
We have a detailed Projector Variable Lens Shift Guide ».
Document Camera[ top ]
A few projectors on the market today, mostly in the Toshiba line, allows the presenter to switch from a computer or video player’s source to live images from the camera itself. This is a handy feature for showing 3D objects, transparencies, or anything which is either too fragile or too large to be digitally scanned beforehand.
Think of the document camera as a 21st century overhead projector!
We have a detailed Projector Document Camera Guide ».
Lamp Hours (Half Life)[ top ]
Typically and under standard conditions a projector lamp will last between 1,000 and 2,000 hours, but there are many different factors that can influence that value. This is not a guaranty, but on average the lamp life should fall within that range. Projector lamps will last the longest in operating environments that are relatively dust free and used under normal conditions of three to five hours per day. Those that are used more often or are in environments that include dust and moisture, or are subject to overheating temperatures will fail sooner.
The “half life”is the point where the lamp is half as bright as it was when it was new. The lamp will still work at is half-life but will continue to gradually lose brightness. Longer lamp life means less expense in maintaining your projector. Replacement lamps run approximately $200 - $400.
We have a detailed Projector Lamp and Bulb Guide ».
LCD vs DLP[ top ]
Up until a couple years ago most projectors were based upon the LCD technology, where the light from the lamp is filtered through the LCD panel. The light is the recombined, using a dichroic prism. The combined now in full color passed through the lens and hits your screen.
For DLP, start with a lamp source. Instead of passing the light through an LCD panel, it is reflected off of a DLP chip (which has hundreds of thousands of tiny mirrors), which modulates the light. This reflected light of the color wheel allows the light to come out the correct colors and pass through the lens on its way to the screen.
DLP projector technology is generally preferred for home cinema and portability. However there has recently been developments within the LCD projector home cinema category, with some models now claiming a contrast ratio of up to 10,000:1! LCD projectors are generally better where color reproduction is critical, although DLP projectors are working towards a much better color accuracy.
There are some great LCD and DLP machines available on the market, and with all technologies both are always improving.
Price[ top ]
The prices of projectors have dropped considerably in the last few years and we expect they will continue to drop as more and more people look at this option.
Weigh up the features you need before buying to get the best value!