FIRST VERSUS SECOND FOCAL PLANE
In variable-magnification optics, the magnification setting for the use of the mil dot reticle is determined by whether the reticle is in the first or second focal plane. The easiest way to determine if the mil dot reticle is in the first focal plane is to view the reticle through the scope while changing the magnification setting. If the size of the reticle appears to change
as the magnification setting is changed, the reticle is in the first focal plane. If it does not appear to change size, it is in the second focal plane.
If the reticle is in the first focal plane, no specific magnification setting is required to obtain the proper subtension to yield accurate range estimating results.
When the Leupold® Mil Dot reticle is installed in the second focal plane of an optic, it is calibrated to a specific magnification for range estimating purposes. In a variable-magnification scope, this is generally the highest magnification setting and all range estimating must be performed at this setting. However, in certain scopes it may be calibrated for a different setting. If you are uncertain to what setting your scope is
calibrated, contact Leupold Customer Service.