As binocular enthusiasts share their passion, topics related to collimation abound. Typically, we find how observers, armed
only with a jeweler’s screwdriver, can “perfectly collimate” his or her binocular, make it “spot on,” or other verbiage of
Unfortunately, what most are addressing is a form of pseudo-collimation I have referred to since the mid-1970s as
“Conditional Alignment.” Ignoring the importance of the mechanical axis (hinge) in the alignment process, this “condition,”
while having the potential to make alignment serviceable, or even outstanding—within a small range of IPD (Interpupillary
Distance) settings relative to the user’s spatial accommodation (the ability to accept small errors in parallelism of the optical
axes)—may take the instrument farther from the 3-axis collimation conscientious manufacturers seek to implement.
Becoming more optically savvy—and especially with so many mechanically inferior binoculars entering the marketplace—
the consumer contemplating self-repair and alignment has a need to understand the difference between clinical, 3-axis
“collimation” (meaning both optical axes are parallel with the axis of the hinge) and “conditional alignment,” as differentiated
in this paper. Furthermore, I believe there has been a long-standing need for the term “Conditional Alignment,” or some
equivalent, to be accepted as part of the vernacular of those who use binoculars extensively, whether for professional or
recreational activities. Achieving that acceptance is the aim of this paper.