# Homework Help: Local linear increase of the lens

1. Aug 24, 2014

### Evgenii

1. The problem statement, all variables and given/known data

Hello!
I need to find a local linear increase in the field of the lens.

I have Listing of Field Curvature Data.

It contains vectors of - Y height, Tan Shift, Sag Shift, Real Height, Ref. Height, Distortion.

I can not understand how these data get what I need.

2. Relevant equations

Local linear increase in the field of the lens is the ratio of the size of a small object (in the limit of the size tends to zero) located at any distance from the lens center (in this case, the axis Y) to its size in the middle of the field.

3. The attempt at a solution

Real Height/Ref. Height ratio is close to Distortion, but not equal, may be it is answer?

Last edited: Aug 24, 2014
2. Aug 28, 2014

### Greg Bernhardt

I'm sorry you are not finding help at the moment. Is there any additional information you can share with us?

3. Aug 29, 2014

### Evgenii

These data appear as those that are presented here:
http://www.johnloomis.org/eop601/designs/kidger1/zemax.html

In section Listing of Field Curvature Data.

Real Height/Ref. Height ratio is not the answer.
Relative local linear increase in the center of Y = 0 is taken as 1.

Sorry, that's all.