How do you cope with contrast optimization when optimizing on a system where the focal length is still to be determined (to be optimized within a range)?
In this case the MTF frequencies at which contrast is evaluated are constantly changing.
Say I have to meet a contrast specification at specific spatial frequencies defined at the object plane.
Zemax calculates contrast at the image plane, therefore to use contrast optimization I must set fixed contrast frequencies. Fixing contrast frequencies at the image plane forces me to lock EFFL and magnification, but those parameters might have been exploited as useful degrees of freedom in the optimization.
This can be the case when, for example, one is optimizing an intermediate imaging stage and image size is not strictly bound to sensor dimensions.
I don't think there's a way to tell Zemax to update contrast frequencies at each optimization interation, even with API. If this is the case, should I simply stick to spot radius optimization?
Can you think at some workround? Not necessarily Zemax-wise. I’m thinking, more broadly, to the design workflow as a whole.
