High-speed photographic or cinematographic varifocal objective

Claim 1

AN OPTICAL OBJECTIVE SYSTEM COMPRISING A PRINCIPAL OBJECTIVE AND AN AFOCAL ATTACHMENT IN FRONT OF SAID PRINCIPAL OBJECTIVE; SAID ATTACHMENT CONSISTING OF FOUR COMPONENTS SEPARATED FROM ONE ANOTHER BY VARIABLE AIR SPACES, SAID COMPONENTS INCLUDING A FIXED FRONT COMPONENT OF POSITIVE REFRACTIVITY, A FIRST INTERMEDIATE COMPONENT OF NEGATIVE REFRACTIVITY, A SECOND INTERMEDIATE COMPONENT OF NEGATIVE REFRACTIVITY AND A FIXED REAR COMPONENT OF POSITIVE REFRACTIVITY, SAID FIRST AND SECOND INTERMEDIATE COMPONENTS BEING MOVABLE, RELATIVELY TO EACH OTHER AND TO SAID FRONT AND REAR COMPONENTS, INTO A FIRST POSITION IN WHICH THE SYSTEM HAS A RELATIVELY SMALL FOCAL LENGTH AND A SECOND POSITION IN WHICH THE SYSTEM HAS A RELATIVELY LARGE FOCAL LENGTH; SAID REAR COMPONENT HAVING A FOCAL LENGTH EQUAL TO AT MOST 75% OF THE FOCAL LENGTH OF SAID FRONT COMPONENT; SAID FRONT COMPONENT HAVING A FOCAL LENGTH LESS THAN FOUR TIMES THE FOCAL LENGTH OF SAID PRINCIPAL OBJECTIVE; SAID FIRST INTERMEDIATE COMPONENT CONSISTING OF TWO CLOSELY JUXTAPOSED LENS MEMBERS OF NEGATIVE REFRACTIVITY SEPARATED BY AN AIR SPACE OF NEGATIVE CONFIGURATION, SAID LENS MEMBERS BEING OF SUBSTANTIALLY PLANOCONCAVE SHAPE WITH CONCAVE REAR SURFACES AND INCLUDING A SINGLET PRECEDED BY A DOUBLET WITH A FORWARDLY CONCAVE COLLECTIVE CEMENTED SURFACE, SAID SINGLET AND DOUBLET EACH HAVING A CONCAVE REAR SURFACE, THE REAR SURFACE OF SAID SINGLET BEING MORE STRONGLY CURVED THAN THAT OF SAID DOUBLET SAID PRINCIPAL OBJECTIVE CONSISTING OF FOUR AIRSPACED LENS MEMBERS INCLUDING A POSITIVE FIRST MEMBER, A NEGATIVE SECOND MEMBER, A POSITIVE THIRD MEMBER AND A POSITIVE FOURTH MEMBER, SAID FOURTH MEMBER BEING A BICONVEX LENS WITH FRONT AND REAR SURFACES RESPECTIVELY HAVING A SHORTER AND A LONGER RADIUS CURVATURE WITH AN ABSOLUTE RATIO LESS THAN 1:3.