Hi everyone!

I'm working with an optical system that operates using a single field (an on-axis collimated beam - object at infinity), and I’d like to estimate its distortion.

As I understand it, distortion is typically evaluated by comparing multiple fields, so I would need to add additional ones to get a result. However, I’m wondering if there’s a way to estimate distortion using only one field.

I've attached a layout screenshot showing the image space of the system. Is it possible, for example, to infer distortion by analyzing the standard deviation of distances D1, D2, D3, D4, etc.? Presumably, if distortion were zero, these distances would all be equal (I already developed that metric in Non-Sequential raytraces with the API). I realize this is limited to a single axis, but switching to Non-Sequential mode isn't an option in this case, as the system includes a black box component.

Any insights would be greatly appreciated.

Thank you!