Endoscope

A stereoscopic endoscope comprising:

• a first channel comprising a first objective lens system, a first relay system, a first ocular lens system, and a first optical path, the first objective lens system being optically coupled to the first ocular lens system through the first relay system, and the first optical path extending through the first objective lens system, the first relay system, and the first ocular lens system;
• and
• a second channel comprising a second objective lens system, a second relay system, a second ocular lens system, and a second optical path, the second objective lens system being optically coupled to the second ocular lens system through the second relay system, and the second optical path extending through the second objective lens system, the second relay system, and the second ocular lens system;
• wherein the first ocular lens system and the second ocular lens system each comprises a first positive lens, a second positive lens, and a negative lens, the first and second positive lenses and the negative lens of the first ocular lens system being disposed in the first optical path, the first and second positive lenses and the negative lens of the second ocular lens systems being disposed in the second optical path, and
• wherein the negative lens in the first optical path is configured to be movable off the first optical path and the negative lens in the second optical path is configured to be movable off the second optical path so as to stereo match the first channel with the second channel.