Adjustment
Adjustment is the precise fine tuning between mechanics and optics
Under a Adjustment for binoculars is the parallel alignment of the two halves of the binoculars.
If binoculars are knocked hard or fall to the ground, for example, the Prisms postponed and the GlassIn addition to the coating of optics, the glass quality or type of glass is one of the most important quality factors for binoculars and riflescopes " More info is misaligned.
Consequence of misalignment in binoculars
When observing through a misaligned binocular model, the contours appear shifted to the observer (Double image). A slight misalignment of the model may be compensated for by the accommodation (adjustment) of the eyes, but headaches will occur with prolonged viewing. In any case, misaligned binoculars must be brought in for repair.
