A drilling stand with fine adjustment control will allow a series of photos to be taken in steps as small as 0.03 mm along the lens axis
, and is stable enough to avoid any significant variation in the x and y axes during this process (Fig.
If the iris has been closed down to a small opening, the extreme edges of the camera target will receive light rays at an angle of AOV/2 from the lens axis
. This is the maximum angle because almost all the light imaged by the lens will pass through the lens center.
"Thick and thin cut machines historically couldn't co-exist, because of the many differences in aperture, lens axis
, focal point and beam delivery characteristics," elaborated Gay.
The camera position is adjustable in four directions, allowing for adjustment of pan, tilt, vertical position, and rotation about the lens axis
The analysis depth is proportional to the mean free path of an escaping photoelectron and the sine of the angle between the analyzer input lens axis
and the surface of the sample.
This means that should the axis of the ocular astigmatism fall between two available parameters in a range of toric lenses (eg, axis of 95, with lens availability being 90 or 100), then it is reasonable to assume the lenses may rotate anti-clockwise (right) in the right eye and clockwise (left) in the left eye when deciding which trial lens axis
to select initially.