Structure of loupes

This adjustment is controlled by turning the interpupillary adjustment knob back and forth, until the image converges into a circle.
For Kepler Loupes(4.0x to 6.0x), each optics can be independently adjusted until the image coverages into a circle.

Follow the drawing to adjust the hinge mechanism, so that the optics are angled approximately 30 to
45 degrees below a horizontal line. This will allow  the user to look down into the optics while working,
while still allowing you to maintain an upright, ergonomic posture.