Hi,
I have a file of an exisiting lens with floating elements. The file consists of multiple BlackBox elements. Included are also multiple setups with different object distances and the respective thickness that detmermines the position of the floating element for the given focus position.
I would now like to calculate additional config for which I want to calculate the object position and floating element position for a given magnification.
My idea was to define in the MFE the desired PMAG and set the boundaries for the floating element using TTHI+ABLT and TTGT.
However, when I let Zemax optimize this setup it will generate thicknesses that are wrong (=not focus on the image plane and thus very low MTF). Even when I set the object distance to a fixed value that I know from the other configurations it will not find the best thickness for surface 7.
When I set the thicknesses for surf0 and surf7 by hand the focus is correct.
Can someone tell me what I am missing here? What constrains Zemax to calculate the ideal thickness fur Surf7?
Below are the MFE and MCE. I added a drawing instead of sharing the lens data in order to not share any protected data.
![](https://uploads-us-west-2.insided.com/zemax-en/attachment/8eab8c39-4701-4d09-8ab5-abd142b43395.png)
![](https://uploads-us-west-2.insided.com/zemax-en/attachment/d4fdbac5-6a42-4ca6-899a-11b16c037a7e.png)
![](https://uploads-us-west-2.insided.com/zemax-en/attachment/56cbd71e-9eed-413f-b69c-6c5b4c3dc579.jpg)
And the unfocused image plane:
![](https://uploads-us-west-2.insided.com/zemax-en/attachment/f8054b50-18e2-4700-992e-74199e7a32a9.png)