company news about Projection Science: Analysis of Common Projector Lenses and Projection Parameters!

When buying a projector, have you ever found that you can't understand a lot of parameters of the projector, such as lens, projection ratio, brightness, lumens, etc.? In fact, different projection performance directly affects the projection experience. Whether it is the projection lens or various parameters, they all directly affect the projection experience.

There are three common projection lenses. The projection lens is a key factor affecting the quality of the projection image. Different lenses directly affect the clarity, color, brightness, uniformity, etc. of the projected image.

1. Short-focus lens, which is used to project a large image at a short distance.

It is generally used in small classrooms, small conference rooms and other environments with strict space requirements. 2. Telephoto lens, used to project a small image at a long distance. It is generally used for engineering machines, which is convenient for long-distance installation of some projects. The zoom range is large, which is convenient for adjusting the installation position of engineering machines. 3. The ball screen lens is a single lens projecting a spherical surface. Analysis of projection parameter performance 1. What is the projection ratio? The projection ratio is the ratio of the projection distance to the width of the picture, that is, the projection ratio = projection distance/screen width. The smaller the projection ratio, the larger the width of the projected picture at the same projection distance. (When the projection ratio is >1, it is a telephoto lens, when the projection ratio is <1, it is a short-focus lens, and when the projection ratio is <0.6, it is an ultra-short-focus lens)

2. What is the focal length F value?

Focal length F is also expressed in numerical values, usually ranging from 50-210, and is divided into short-focus, standard and long-focus, as well as ultra-short and ultra-long-focus. The smaller the value, the shorter the focal length, and the larger the value, the longer the focal length. The focal length determines the distance between the projector and the screen when the predetermined size is full. The shorter the focal length, the closer the distance between the projector and the screen, and vice versa. If you want to project a large image at a short distance, you need to choose a projector with a short-focus lens, otherwise you need to choose a long-focus lens. Most projectors have standard lenses.

According to different needs, the lenses that can be replaced are: wide-angle lens for shortening projection distance, rear-projection wide-angle lens for shortening rear-projection distance, and telephoto lens for extending projection distance. These lenses with different focal lengths are very convenient to replace. Generally speaking, the operator only needs 1-2 minutes to complete it without any tools.

3. What is zoom ratio?

The so-called zoom ratio refers to the ratio of the longest focal length to the shortest focal length of the zoom lens, which is what we often call the optical zoom. The zoom ratio is a ratio, so it cannot fully reflect the zoom level of the projection lens and the performance of the lens.

4. What is light transmittance?

The light transmittance of a projection lens refers to the ratio of the brightness per unit area of ​​the projection screen after installing a short-focus or long-focus lens to the brightness per unit area of ​​the projection screen when using the original standard lens. Since the light structure of short-focus lenses and long-focus lenses is more complex than that of standard medium-focus lenses, more lenses are used. Due to lens refraction, short-focus lenses and long-focus lenses lose more brightness than standard lenses, so the light transmittance of short-focus lenses and long-focus lenses is lower than that of standard lenses.

To sum up, the projection effect is a comprehensive performance, and it is not determined by a single hardware indicator. In addition to the restrictions of the projector on the lens structure, while ensuring the display is clear, color, brightness, uniformity, distortion, aberration, dispersion, etc. all affect the image quality of the projector.