How to differentiate the long or short focus laser projector?
The long focus projector is an engineering machine lens that facilitates long-distance installation of some projects. The zoom range is large and it is convenient to adjust the installation position of the engineering machine. The short-focus lens is a large screen for short-distance projection, and the projection ratio is a projection screen size. The ratio to the projection distance is the property value of the lens. It is not necessary to study this. The general short focus is about 80 inches for 1M. The shortest is the principle of reflection. 30CM can be used for 100 inches, but the cost is higher.
Meanwhile, regarding the standard of the throw ratio, we think that when the throw ratio is less than 1, it is called a short-focus lens; and when the throw ratio is below 0.6, we usually call it a short-short lens. From the past telephoto lens to the current ultra-short-throw projection products, we can see the development of projectors in recent years.