### Step 6 of 8: Heights

This too, it just a matter recalling that the heights is the distance from the optical axis to the edge of the lens (i.e., half the diameter of the lenses). The only thing remotely tricky is to make sure that the heights of the front and back surfaces of the lens is exactly the same.

$h_1$ $h_2$ $h_3$ $h_4$
mm mm mm mm
DCX 10 10 10 10
PCX 8 8 8 8

This is pretty easy because I selected the lenses for each telescope to be consistent.