What happens to the reticle when the magnification is changed?Updated 2 days ago

The behavior of the reticle during magnification changes is determined by its position inside the riflescope. A riflescope has two focal planes. If the reticle is located in the first focal plane, it is magnified along with the image when the magnification changes, and the size ratio (coverage ratio) of the reticle to the target always remains the same. This makes it possible to estimate the distance to the target at any magnification using the known spacing between the reticle markings.
When the reticle is in the second focal plane, the size of the aiming mark remains constant. This results in different coverage ratios of the reticle at different magnifications. Estimating the distance is hardly possible here. However, this setup allows for a precise shot even at greater distances, as the aiming mark covers very little of the target.