Eye box?

They're referring to the area in which you can place your eye and still get a good sight picture - i.e. not seeing a shadow on any edge of the scope. Your problem could also be related to parallax which results in the crosshairs moving when your head changes position. Scopes without a side-focus usually have a parallax adjustment at the eyepiece. A quick way to check for parallax is just to move your head a little bit while focusing on the crosshairs - if the crosshairs move to point to another spot, you have parallax issues.

HTH,



GsT
 
They're referring to the area in which you can place your eye and still get a good sight picture - i.e. not seeing a shadow on any edge of the scope. Your problem could also be related to parallax which results in the crosshairs moving when your head changes position. Scopes without a side-focus usually have a parallax adjustment at the eyepiece. A quick way to check for parallax is just to move your head a little bit while focusing on the crosshairs - if the crosshairs move to point to another spot, you have parallax issues.

HTH,



GsT


Yep, sounds like parallax. I learned about it the hard way, it was driving me nuts. Do a Youtube search.