optical viewers
观察的英文_观察翻译_观察英语怎么说_海词词典 ... 观察仪 scope; observer; finder 观察仪器 optical viewer 观察员 observer; inspector ...
viewing device
... viewing angle ==> 视角=>视野角 viewing device ==> 观察仪器,观察装置 viewing distance ==> 观察距离,视距 ...
optical electronic viewing instrument
nonstereoscopic viewing instrument
stereoscopic viewing instrument