camera fig3 and 4 show stereoscopic coupler 5 secured to a stereo endoscope 10 fig3 and stereoscopic coupler 5 secured to a stereo endoscopic camera 15 fig4 functionally and looking next at fig5 7 stereoscopic coupler 5 may be considered to constitute three main sections each providing a different function and serving a different purpose i a u201c scope locking u201d section situated distally on stereoscopic coupler 5 and comprising the distal portion of the main housing 20 front flange 25 front cover 30 a bail 35 and a radial locating pin 40 ii a u201c focusing mechanism u201d section situated primarily in the middle of the stereoscopic coupler and comprising the middle portion of the main housing 20 focusing ring 45 binocular cell housing 50 cam ring 55 elastomeric seals 60 a 60 b load ring 65 clutch plate 70 return springs 75 a 75 b and cam pin sockets 80 a 80 b and iii a u201c camera attachment u201d section situated proximally on stereoscopic coupler 5 and comprising the proximal portion of the main housing 20 and a sensor mounting plate 85 which is mounted to the image sensor not shown of stereo endoscopic camera 15 the following is the description of some of the distinct features and operational principles of stereoscopic coupler 5 the u201c scope locking u201d section receives aligns and securely locks in place a stereo endoscope e g the stereo.