内镜筒的英文

• inner lens cone

• 内:    inner; inside; within
• 镜筒:    lens cone
• 单镜筒:    monocular tube
• 活镜筒:    draw tube; drawtube
• 目镜筒:    eyepiece sleeve; eyepiece stalk

例句与用法

1. As you can see above the lens extends a little bit towards closer focus distances
   向近处对焦时内镜筒会略微伸出一段。