Projectors are an indispensable part of every seminar, presentation or meeting. There are innumerable ranges of projectors offered in the market and potential buyers face a dilemma of choosing from the overwhelming array of features and options. There is always a list of key-features which may govern the requirements and demands of every customer and these needs are to be considered before purchasing any projector.

The most basic and the key specification features of portable projectors are Resolution, Luminosity, Dimensions, Room and Computer Connectivity and additional high-end classification like Contrast Ratio, Aspect Ratio etc. A novice buyer would only need to look at the fundamentals key parameters to choose the correct projector.

The resolution of a projector is measured by the number of pixels which are projected onto the screen or more specifically by the number of horizontal and vertical pixels in the image. The greater the number of pixels results in a comparatively tighter packing of pixels on the screen and thus a relatively smoother or finer display of the image. The generalized terms used to refer to the pixel resolution on the screen by the different configurations are – VGA (640×480 pixels), SVGA (800×600 pixels) Standard, XGA (1024×768 pixels), high resolution which is the build technology in laptops, SXGA (1280×1024) mostly used for CAD, GIS and other special graphic applications and UXGA (1600×1280) large format. The projector should match the number of screen pixels on the laptop computer which is driving the projector to ensure the best projection display on the wide screen.

The luminosity factor of the projector is the brightness or the quantity of light projected onto the screen which is measured in terms of an international ANSI standard called Lumens. The visibility factor of the displayed image is directly proportional to the luminosity in a way so that higher luminosity results in a brighter and more clearly visible image and similarly, a greater number of Lumens are required for image projection in case of a greater distance between the projector and the screen. Typically, a projector supporting a minimum 1000 lumens is required to project at a distance of 20 feet.

The dimensions and weight factor of a projector would be decided by the place where the projection is done. The roadside or constantly movable projections demands a small and a lightweight projector between 6 and 10 pounds. Also available are ultra portable projectors which weigh between 2 and 6 pounds. The projector comes with a robust and sturdy case to keep it safe in case of moving and transferring.

The room where the projection is held should comply with certain regulations to portray a projected image and similarly the type of the projector also depends on the room specification. For example, the lighting facilities in the room, the size of the room governs the amount of lumens to ensure the image brightness and its clarity. The lightning in the room would be made keeping in mind the requirements of the target audience and their needs. The setup of the projector and the screen should be made according to these factors and experimentation with the projection and distance between the screen and projector, lightning, etc should be done earlier to ensure a perfect presentation.

The connectors of the projector should be compatible with the laptop computer used with it and can be checked in the "full specification" section of the projector information book. The common connector's features are the number of pins on the interface cables – 15-pin, VGA, S-Video, RCA, etc.