Hi Amir,

FLWT changes the weight given in the merit function for a field, but does not alter the field value, in this case the object height. A zero weight does not eliminate the field, it just gives it zero weight in the merit function.

To alter the object height use the YFIE operand. You can change your design to have a single field, and alter the Y value of that field by using YFIE in the multiconfig editor.

Hi David,

Thanks for your answer!

By YFIE I can change the field height in object space. It works fine. But at image plane how could you realize the off-axis value? 

Kind regards,

Amir

Hi Amir,

YFIE changes the field based on its definition in the System Explorer.

If your field definition is Paraxial Image Height or Real Image Height, YFIE will modify the image height.

Let me know if this answers your question.

Take care,

David

Hi David,

I mean when I change the object height using YFIE, how can I obtain the off-axis value at the image plane? I can see the off-axis shift for different object height in spot diagram, but I’m looking for the value. 

Bests,

Amir

Hi Amir,

I see, sorry for the confusion. You could use a Merit Function operand like REAY. If you specify the off-axis field with Hx and Hy, and keep Px and Py at zero, REAY traces the off-axis chief ray and measures its Y-coordinate. The same works with REAX along the X-axis.

Let me know if this works for you.

Take care,

David

Hi David,

The REAY gives what the IMA here at the spot diagram gives? Does this represent the shift?

Bests,

Amir

Hi Amir,

It depends on the settings of your spot diagram. If your setting is Refer To: Chief Ray, then REAY like I documented will be exactly what IMA is for a given wavelength. If you use Wavelength: All I think it always displays IMA for the primary wavelength.

Here is how it looks like in an example:

I hope this makes sense.

Take care,

David