06-09-2020 10:47 AM
Keep in mind, using a tele-con does not change the physical aperture. You are magnifying an image that is already projected by the lens. The physical aperture is unchanged so the depth of field is unchanged.
06-09-2020 10:54 AM - edited 06-09-2020 11:50 AM
Since the "circIe of confusion" is changed, I think that the DOF is changed too, just like the fact that the DOF changes when you use the same lens on FF vs APS-C.
This is wrong, the change in depth of field is entirely due to the effective increase of the focal length.