Q: What is night vision for the optical telescopes?
A:Night vision is the ability to see in low light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range.
Night vision technologies can be broadly divided into three main categories: image intensification,
active illumination and thermal imaging. The Optical telescopes use the principle of Image
intensification to achieve the function of night vision.
Image intensification magnifies the amount of received photons from various natural sources such as starlight or moonlight. Therefore, under low-light conditions, through the optical telescope we can only see the fuzzy image, except for the stars. We call it "Low Light Night Vision".