L7 Cylindircal and spherocyl surface and lens

Question 1

explain principal meridians

Answer 1

the two meridians of a cylindrical or spherocylindrical lens that represent the minimum and maximum powers, they are 90 degrees apart

Question 2

define axis meridian

Answer 2

the meridian of a cyl/spherocyl lens that contains the minimum or zero power

Question 3

define power meridian

Answer 3

the meridian of a cyl/spherocyl that contains the maximum power

Question 4

compute power between meridians

Answer 4

max power x sin tether square

Question 5

object image relationship for cyl lens

Answer 5

a point object has a line image with the orientation of the line image parallel to the axis meridian

Question 6

explain object image for spherocyl lens

Answer 6

since it may be expressed as two cylinders, a point object will thus have two line images (at right angles to do), one formed by each cylinder

Question 7

what is interval of sturm

Answer 7

the distance between the two line images

Question 8

what is circle of least confusion

Answer 8

in the interval of sturm, the position where the major and minor axes are equal (a circle). the image plane that contains the circle of least confusion has equal blur in all directions, the vergence in this plane is the average emergent vergence leaving the plane