Hi Jeeyoung,

Thanks for posting on the forums! For your Question 1, are you asking how to find the stop, specifically? In the Lens Data Editor, you can specify the Stop to be any surface. This would generally be most appropriate to set for the surface that will actually be the limiting aperture for your optical system. However, for a system that is telecentric in Object Space, you are effectively forcing your Entrance Pupil to be placed at infinity. So you are 'overwriting' what the limiting aperture would really be, in a sense, since you are directly defining the chief rays of all your field points across the Object surface.

Regarding Question 2, I would say the only requirements are that you do not have your Field Type set to Angle, as otherwise you will not be able to toggle the setting on:

I would also recommend only using this setting when the Object surface is at a finite distance away, as it's meant to model the output of light from things like displays or output fibers.

Let us know if you have any more questions here, or if I've missed any details on this!

~ Angel