Monocular stereoscopic camera

A monocular stereoscopic camera comprising:

• a first imaging lens assembly,
• a half mirror (H) configured to reflect a portion of a light beam passing through the first imaging leans assembly and allow the other portion of the light beam to pass therethrough;
• a first camera comprising a third imaging lens assembly configured to image the light beam having been reflected by the half mirror (H);
• a second camera comprising a third imaging lens assembly configured to image the light beam having passed through the half mirror (H);
• and
• second imaging lens assemblies arranged on an optical axis between the first imaging lens assembly and the half mirror (H) or an optical axis between the half mirror (H) and the third imaging lens assemblies,
• wherein at least one of the second imaging lens assemblies moves along an optical axis, to change focal positions of the third imaging lens assemblies or to make the size of an image of the first camera and the size of an image of the second camera be equal to each other.