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https://www.projecticodis.com/blogs/insight/the-benefits-of-using-a-handheld-3d-scanner

The size of space
The size of the space is the size of the living room, movie room, etc. where you use the mini home theater projector . If your living room area is more than 20 square meters, you can consider buying a projector; if not enough, it is not recommended.

Price
The price gap of projectors is large, generally from a few thousand yuan to about 50,000, or even higher. The prices of foreign brands are higher than domestic prices. Domestic projection prices are lower. The reason is not explained in detail. For most consumers, products below 30,000 yuan can meet household needs.

Brightness
Brightness is one of the most important indicators for purchasing a projector.

Noise
Those who have never used a projector do not know that the projector will make noise when used. The noise of some projectors can severely affect viewing and is unbearable. When purchasing a projector, considering low noise should be an important part of the purchase. At present, many manufacturers have launched low-noise projectors, and the price is not expensive. Generally speaking, products with a noise level below 40dB are acceptable, but when buying, you should listen and compare yourself in a quieter environment to see if it will interfere with yourself.

Choose DLP or LCD
Whether it is LCD or DLP is actually not so important. What we need to see is the effect of the projector. And the effect of a projector is inseparable from many things such as lenses, light bulbs, and circuits. In principle, LCD projectors are the most common and their prices are relatively low. The biggest advantage of LCD projectors is that the colors are great. The three primary colors of red, green and blue are completed by three separate LCD panels. The brightness and contrast of each color can be controlled individually. And three colors of light can reach the screen almost simultaneously, so various colors can be reproduced realistically. Although the color reproduction of DLP projectors is slightly worse, the three-color light of a single-chip DLP projector is reflected by the same micromirror to the same pixel, and there is no convergence problem, so the black area is truly black, and the edge of the pixel will not appear Some burrs and shadows in the LCD. Therefore, when showing some thin lines, DLP projectors are clearer and sharper than LCD projectors, black and white are more pure, and gray levels are richer. Of course, the biggest advantage of a single-chip DLP projector is its small size and light weight. Many products even have only 1-2 kg. Generally speaking, DLP projectors are slightly more expensive. Seeing is believing. Whether it is LCD or DLP, it is recommended to compare carefully at the time of purchase.

Trapezoidal correction
In the use of the projector, the position of the projector must be at right angles to the projection screen as far as possible to ensure the projection effect. If the verticality of the two cannot be guaranteed, the picture will be trapezoidal. If it is not on the ceiling, but on the table, it is difficult for us to guarantee "vertical". In this case, we need to use the "keystone correction function" to correct the keystone to ensure that the picture has a standard rectangle. Keystone correction usually has two methods: optical keystone correction and digital keystone correction. Optical keystone correction refers to adjusting the keystone by adjusting the physical position of the lens; another type of digital keystone correction is software to achieve keystone correction. At present, almost all projector manufacturers have adopted digital keystone correction technology, and most of the projectors using digital keystone correction support vertical keystone correction function, that is, the projector can adjust its height in the vertical direction. The resulting trapezoidal is trapezoidally corrected in the vertical direction by the projector. The picture can be made rectangular, which is convenient for users.