Question about auto_lens_design parameters

[TisaiYu]

I am trying to design a len to simulate blur image and analyse the PSF. In .config/auto_lens_design.yml, I want to design my own len which has the same parameters with my real len to take blur image. The parameters are below.
focal length: 50mm
sensor diagonal length: 11mm (2/3'')
F-number: 1.4
Then I calculate the HFOV to be 6.3°, so I set the file parameters as the picture below.

However, I got an error with calculating the exit_pupil()

I change the parameters and found that HFOV>0.34 could work but FOCLEN is only 15.55mm.
Is there any restricted range of the parameters?
How can I get a len with the parameters I want?
If the auto-lens can generate lens with small HFOV and large focal length?
I am going to read the source code deeply, but I will appreciate it if someone give me the answer early.

[singer-yang]

Hello TisaYu,

Thanks a lot for your interest! This error occurs because the aperture stop is much larger than the image sensor, causing a pupil calculation failure when initializing the lens. You can resolve it by using FNUM_START (set it to 8.0 for your case) to initialize a lens:

Also, I would recommend that you delve into the source code as the AutoLens code is currently optimized for cellphone lens designs (large FoV, short total thickness length). I assume you are designing a microscope lens. An important recommendation is to set the total thickness length to a reasonable value.

AutoLens could provide better optimization capabilities than Zemax because it relies on gradient computation for optimization. However, we have not yet been able to develop a software that meets the needs of all users.