2022-09-07

Contact Engineer manager

WhatsApp/ Wechat:   0086-18792456795

Email: mh_elec@126.com or jacky@mh-elec.com

Telescopes and night vision devices are two types of optical observation instruments that everyone is familiar with in daily life, and most people often cannot tell the difference between the two. In fact, telescopes and night vision devices are two completely different products. Let's take a look at the specific differences between the two. But before analyzing the difference between telescopes and night vision devices, we must first have a brief understanding of the definitions of the two.

A telescope is an optical instrument that observes distant objects using lenses or mirrors and other optics. It uses the refraction of the light through the lens or the reflection of the light by the concave mirror to make it enter the small hole and condense the image, and then pass through a magnifying eyepiece to be seen. Telescopes can be divided into 10 types, refracting telescopes, reflecting telescopes, infrared telescopes, digital telescopes, etc. 

The night vision device is an external sight at night with the image intensifier tubes as the core device. It does not use infrared searchlight to illuminate the target, but uses the light reflected light from the target under weak illumination to enhance the visible image that can be felt by the human eye on the fluorescent screen through the image intensifier to observe and aim the target.

Second is that the use conditions and environments of telescopes and night vision devices are different. A telescope is an optical instrument that directly uses a lens to magnify objects on the retina for imaging. It does not use power and cannot be used in a completely dark environment. The night vision device is an instrument that uses the principle of image enhancement or infrared imaging for observation. Although the clarity is not as good as that of a telescope, it is suitable for observation in complete darkness or in the environment of stars and moonlight. Therefore, this also leads to the difference in imaging principles between telescopes and night vision devices. 

 The principle of telescope imaging is similar to small hole imaging, the objective lens focal length is longer, the function is to make the distant object in the focus of the eyepiece, close to the focus near the inverted, reduced real image; Eyepiece focal length is short, the effect is equivalent to a magnifying glass, used to enlarge the real image, relative to the real image, into a vertical, enlarged virtual image.

 The night vision device focuses the light from the target on the photocathode of the image intensifier through the objective lens. The photocathode converts the optical image into an electronic image. The electron gain system is used to increase the energy and number of electrons. The electron image is focused on the phosphor screen, which is illuminated by the bombardment of high-energy electrons, and the user can see the enhanced optical image in the eyepiece. Among them, the role of the image intensifier is to complete the secondary photoelectric conversion, mainly to enhance the weak input image by tens of thousands or even hundreds of thousands of times, making it a target image that is easy to distinguish by the human eye.

Third, in terms of use effect and quality, the magnification of night vision device only 2-4x, and it can only be used in the night or total dark environment; when used during the day, the image intensifier tubes risk being burned out by strong light, which makes night vision much more expensive than telescopes. However, the magnification of the telescope is 7x, 8x, or 10x, which can be used not only in low light conditions at night, but also during the daytime, with the advantage of all-weather observation; in addition, the telescopes have no fragile electronics, so they are much sturdier than night-vision machines.

As optical observation instruments, telescopes or night vision devices can both assist users in observing targets, but because of their different structures and imaging principles, their uses and environments and imaging effects are very different.

Contact Engineer manager

WhatsApp/ Wechat:   0086-18792456795

Email: mh_elec@126.com or jacky@mh-elec.com