Types

• Multimedia units come in a variety of iterations. One the one hand, there are very small units that are perfect for transporting from presentation to presentation, and can often fit into a briefcase. Although the light output on these little marvels is good, that's mitigated by lower resolutions and grainier picture quality. Stepping up one notch are the units that are modest in terms of the high definition segment (typically 1024x768), but begin to display potential in a better home theater environment. In a business setting, these are better for showing video-based presentations, due to their superior video processing and contrast. Finally, the units that excel in a theater environment are the units that display 1080p resolution, have contrast ratings superior to many televisions and are optimized for sources such as Blu-Ray disc. Naturally, these devices are overkill for business applications, unless high resolution and smooth film/video presentations are the norm.
  
  

Features

• Basic features on a digital projector begin with the scaler. These are needed because there is only one resolution that can be displayed--the amount of picture elements (or pixels) on the display's chip, so all incoming sources need to be scaled to that resolution to be displayed properly. The second common feature found on nearly all projection units is the ability to adjust picture quality parameters per input, meaning that static graphical images, such as pie charts, can have different picture settings optimized for that type of source. Video and film based sources require a little different settings to ensure low-level detail and color is correct, and these units allow those adjustments. Finally, the third most common feature is the ability to serve as a second monitor, allowing information from laptops or workstations to be displayed on them at the same time as on the main display. Although this is common on monitors, projectors handle the input in a similar way, allowing presenters to see the same things as the audience, or to "wrap" from the main monitor to the projector.
  
  

Connectivity

• Projectors typically require multiple inputs to be as convenient as possible. Digital inputs, such as DVI and HDMI, allow pixel-perfect images to arrive unprocessed to the projector, ensuring lower noise and fewer artifacts. This type of connection is therefore desirable to the crowd using these devices as movie-watching vehicles. Most common is the VGA connection, found on all computers and laptops. This analog connection is still high-resolution capable, but at the cost of increased noise and picture degradation over distance.
  
  

Misconceptions

• The most common misconception revolves around the lumen rating of the projector. Measured at the lens (not the screen) lumen ratings tell users what the maximum brightness of the projector is capable of. Keeping in mind that viewers look at content on the screen surface means that the reflected lumen rating is of far more significance. In addition, contrast ratios--measuring max black to max white and everything in between--are so often overrated as to make them almost irrelevant. Viewing the unit in a similar environment that it will normally call home is the best judge of performance determination. Like wattage ratings on an amplifier, lumen ratings are meant as a signpost to roughly gauge expectations, not the final arbiter.
  
  

Warnings

• Projectors and their bulbs radiate significant heat immediately around their chassis. This must be vented properly, or the risk of the bulb failing prematurely or the unit itself is very high. Projectors should never be installed in enclosed environments, without adequate cooling, such as an additional fan. Also, bulb housings should never be touched directly. Often, the oil from fingertips is enough to cause the bulb to heat much faster in those areas, possibly causing the bulb to pop. Lastly, bulb replacement warnings should never be ignored. Doing so may result in a catastrophic bulb failure, potentially causing damage to the surrounding electronics. These things are considered abuse, and are generally not covered by warranties.