Define the nature of the source to be displayed.
The frequency of the image scanning, as well as the output from the graphics card, determines the type of projector. Based on the nature of the displayed source, projectors are primarily categorized into two types: standard video projectors and digital projectors. When only full television signals are to be displayed, such as in a karaoke room playing a VHS tape, a standard video projector can be chosen. For displaying signals output from a VGA card, a digital projector should be selected.
2. Confirm Installation Method
Projector installation methods include desktop front projection, ceiling-mounted front projection, desktop rear projection, and ceiling-mounted rear projection. Front projection places the projector and the audience on the same side; rear projection separates the projector and the audience at opposite ends of the screen. For temporary use, choose a desktop or ceiling-mounted setup. For larger spaces with prior planning during construction, rear projection offers the best overall effect. For smaller spaces, consider using the rear projection with refraction method.
3. Understand the display environment, such as the size of the indoor area and lighting conditions.
For rooms up to 100 square meters, a projector with a brightness of about 2,000-3,500 lumens can be selected when there's no sunlight and the lighting is dim. In well-lit environments with ample space for large display areas, opt for a projector with high display resolution and brightness, such as a high-lumen model with 3,000-6,000 lumens.
4. Projection Screen Shopping Tips On-Site
Based on the horizontal scanning frequency range provided by the technical specifications, three frequency levels—high, medium, and low—are selected. The corresponding image resolutions for these three frequency points are then calculated. The projector is checked to ensure it can display normally at these three resolutions. If line synchronization issues arise, such as image twisting or shaking, it indicates poor horizontal scanning tracking.
Inspect the focusing performance using test grids generated internally by a projector, or by a signal generator or computer. Adjust the focus to its optimal position, then gradually increase the image contrast from low to high. Observe whether there is any blurring in the horizontal and vertical lines of the grid. If there is, it indicates poor focusing performance.
Video Bandwidth Inspection: Video bandwidth directly affects the clarity of video details. Generate a high-resolution white background graphic signal that a projector can handle, using a computer or a signal generator, and observe whether the small character graphics on the screen are clear. If the video bandwidth of the projector is insufficient, the horizontal lines on the screen will appear solid, while the vertical lines will appear blurry, and the image details will be unclear.
