Before picking any projector you need to decide the way it would be used. Multimedia models are typically used for both presentations and lectures, for educational and commercial purposes. Families buy projectors as a part of their home theaters and play stations. Portable compact devices called mini or pico-projectors perfectly fit into your bag, so you can easily take them anywhere.
Image projected on the screen should always be of high quality whether the item is used in a class, conference hall or at home. Projectors are optical equipment, so lots of their parameters are described in technical terms relating to the correspondent physics section.
Basic picking criteria for projectors
So, let’s proceed and figure out how to choose projector?
This parameter describes the lamp’s light output in projector and is measured in lumens (lm). Color brightness and white luminance should be also considered. If you see only one lumens number in the device specifications, it typically refers to white luminance. Color brightness is just a third part of the specified number in this case.
This number shows the difference between white and black colors. For example, the ratio 1000:1 means that the lightest white shade is 1000 times brighter than the darkest black shade.
A resolution is a number of pixel points used for displaying the image. High resolution provides clear and clean image, which is especially significant when displaying text and video. Resolution is expressed in two numbers, for example, 800 x 600 corresponds to 800 points horizontally and 600 points vertically, i.e. the picture consists of 480,000 pixels.
Today 4K projectors provide the highest resolution. They make it possible to show a picture consisting of at least 8 million pixels. Vertical and horizontal pixels number may vary depending on the aspect ratio.
For instance, full-screen 4K projector provides displaying 12 582 912 pixels with resolution being 4096 × 3072 on a screen with 1.33: 1 aspect ratio (4: 3, 12: 9).
It can be easily found from width-to-length ratio. 4: 3 is considered to be a normal ratio. Large-format projections have a 16:10 aspect ratio, i.e. they give a horizontally elongated picture. Most projectors for home theaters have 16:9 compression ratio.
Easy to Use
For a more comfortable use the device is equipped with:
- Simple connection
- Quick warm-up
- Projector lamp turn off
- Automatic image correction
This parameter specifies the distance between the projector itself and the image on the screen. Long-focus projectors are perfect for producing images in large rooms, short-focus projectors provide pictures at a 1-2.5 meters distance, and ultra-short-focus projectors, which are basically installed one meter from the screen.
Most projectors have either a single-chip DLP or a 3-chip 3LCD technology. The first one applies a programmed color wheel for pixel color identification. The second one reduces chromatic aberration, which is typical for DLP technology.
There are several connection types for projector:
- USB port makes it possible to connect an item to a computer or a flash drive
- Digital HDMI connection to a laptop and a Blu-ray player
- DVI or VGA display port in order to connect to a monitor, camcorder, and DVD player
Pico-projectors, which become really popular, can be connected to a particular information carrier via Bluetooth or Wi-Fi.
Metal halogen lights are usually used in cheaper projectors. LED light bulbs provide higher brightness. They seldom burn out, live longer, and provide low energy consumption compared to traditional halogen lamps with similar brightness.
Optical magnification is the lens’ function, allowing the user to magnify the image without quality distortion or loss. Quality loss occurs when digital magnification zooms a part of a displayed image.
Lenses on some models are removable, which provides flexibility when using the projector for different purposes and installing the item at different distances from the screen.
Some projectors use a wireless connection to transfer the image from a computer or smartphone to the screen.
Interactive projectors equipped with a special stylus pointer make almost any surface functional, no interactive whiteboard needed. Such models have either short-focus or ultra-short focus allowing projecting the image without glare and shadow from the person standing near the screen.
Lots of multimedia projectors are supposed to be 3D-Ready. In most cases, they operate only with computers equipped with compatible video adapters. Projectors for home theater support HDMI 3D and can be used with Blu-ray players.
Some models are equipped with built-in speakers. If you need to have quality sound while projecting, it’s advisable to use independent speakers system connected via special audio output. Otherwise, the power of built-in speakers should be at least 10 watts.