Very nice results, Bruce.

I want to see if I understand focal length reducers correctly. Based on my readings, depth of field varies proportionately to aperture and by the inverse square of focal length. So if focal length is multiplied by 0.71 (inverse square root of 2) while aperture is made one stop wider (factor of 0.71, also the inverse square root of 2), then depth of field should be the same.

This is assuming that distance to the subject plane in focus doesn't change to compensate for the changed field of view. If the camera is moved closer to compensate for the changed field of view, then I think depth of field is reduced by the inverse square of distance.

Do I have this right or am I missing something?