Hey, I use one, and it is "invisible" to the eye. But it makes whatever is behind it invisible too. Since you shoot up at eles, and they stand taller than we do it ends up obscuring your view or perspective. This is trouble in with eles, and not with the one you are killing.

If you doubt me, go grab one of your rifles with a good open apperature and try it. You will find, as you state, that the thin wide apperature is "invisible." You will also find thaat it obturates, or obscures, a good portion of your total view, or perspective, to the sides and above. For a righty, especially to the right and above.

This is why the open V express sight is prefered - by me at least - for dangerous game.

Edited to say that the closer to the eye the better fot the open apperature, or ghost ring, but the obturation occurs nonetheless.

JPK