When you focus on the target by adjusting the side focus turret, you are actually moving the focus lens back and forth. By moving the focus lens back and forth, the target image formed on the first or second focal plane will move back and forth. Reticle image is at a fixed position regardless of the focus adjustment. (For FFP (first focal plane) scopes, even though there is no reticle on the second focal plane, reticle image will be formed on the second focal plane as well.) When the reticle image and the target image match, you have focused perfectly. When adjusting the side focus turret, please make sure to do it at maximum magnification. If you adjust the focus at low power, when you zoom in at higher power the focal point may shift and thus the image may blur.

*The reason why focus should be adjusted at the highest power : The same as a camera, at lower power focal depth becomes deep and it comes into focus at a wide range from the front of the target to beyond. Therefore, when you zoom in at higher power the focal point may shift and the image may blur. On the other hand, at the highest power focal depth is shallow and it comes into focus at a narrow range. When you decrease the magnification, the focal point will not shift and the image will not blur.

Before adjusting the focus, you would need to adjust the diopter of the eyepiece. Diopter should be set at the lowest magnification. Please see HERE for detailed instructions. 

We hope you continue to enjoy shooting with March Scopes!