I was aware of the ghost ring aperture sight, keith. My use of the threaded ring for a Merit disc, or other aperture disc with a small hole, approximates that. But, it negates the sharpening of focus and extension of field that a very small aperture causes to occur. That was my point. And, I disagree about the distance from the eye. Too many years of shooting "peep sights" have proven this to me. It needs to be very near the eye to get the full benefit of visual sharpening. That gizmo on the top lever won't do it, IMO.
Ghost sights are a compromise, at best, and best used for hunting and quick shots.
SRH
