Hi everyone!

I’m working with an optical system whose image space has to be afocal. Despite this, I still get numerical results for field curvature and distortion as soon as I add a second field. So what exactly are these values referring to when the image is formed at infinity? I have the same question regarding the MTF: how is image quality being evaluated in an afocal configuration?

Additionally, when I use only a single field, Zemax doesn’t report distortion, yet I can clearly see pincushion distortion on my sensor, as shown in the image. Is there a way to quantify this effect?

Many thanks!

Jesús