Frame Measurements have become increasingly important with the addition of digital lens designs. As a lab, we have lost control over the safety margin on lens cutout. The lens designer gives us all of the parameters to process the lens, and we are at their mercy.
Our biggest issue has been the Frame ED (Effective Diameter) measurement. Unfortunately, many have been misinformed about how to measure this.
When we get a job that hasn’t cut out for a customer, what we often see is the LD, or Longest Diameter, placed incorrectly in the ED box. One of the top results in a quick Google search even incorrectly explains how to measure it.