North China Optical Instrument Factory is a large-scale optical and electronic instrument factory affiliated to China North Industries (Group) Corporation. It is located in the center of Beijing, the capital city.
Founded in 1960, North China Optical is located in Chongwen District, Beijing. It is one of the 15 additional complete projects after the 156 projects aided by the Soviet Union. It is the only modern aviation optical bombing sight manufacturer in my country.

North China Optical Instrument Factory was established in 1960, belonging to the former Fifth Ministry of Machinery Industry.
Camera production began in 1980.
In 1982, Huaguang sz-1 35mm head-up camera was produced.
1986 Shanghai Jingdi Valve Factory Huaguang sz-2 35mm head-up camera.
In 1988, the Norinka sz-300 type 35mm head-up viewfinder was produced, and the Norinka sz-4 type 35mm head-up viewfinder was developed and designed.

Huaguang 210mm f4.5 lens (huaguang 210mm), Huaguang IS11 portrait photography lens is a large-scale camera lens produced by the state-owned Huabei Optical Instrument Factory. It adopts a lens structure similar to Heliar, and its excellent The optical performance is excellent, and it is loved by modern large-format photography enthusiasts.

Here, I will share the lens photos of the large-format photography enthusiast “Walker”, and demonstrate the method of observing the lens structure through the lens reflex.
When the light source illuminates the lens at a certain angle, the reflection of the lens is a large spot, while the spot on the glued surface is a small point, and the brightness is darker.
ps: You can observe by closing the small aperture. When you close the small aperture, you won’t get dizzy when you look at both sides. You also need to look at the bright spots and dark spots. The glued place is the dark spot. (Su Jianrong)