When you focus a sight, you cannot make the target appear as sharp as you imagine. The meaning of focusing is to adjust the eyepiece to make the crosshair as clear as possible. You usually only need to focus once on a sight and keep it still. Unless special circumstances require readjustment.

When focusing the sight glass, first look at a light colored wall through the sight glass. You should clearly see the crosshair clearly in focus. If it is not, adjust the focus circle to present it as clearly as possible in focus. Another thing to note is not to stare at the sight glass for too long, otherwise your brain will adjust your eyes to see the cross hairs clearly (in fact, the focus of the mirror is not aligned). There are refractive indicators on some scopes. Once the sight is aligned with the zoom, it does not need to be changed unless the user's eye line of sight changes, and a cautious user knows where this ring is set. If there is a mark on the sight, it will allow the user to refocus and return to the mark by adjusting this ring, which is more convenient than re executing the entire focusing process.