[Hammerslagger]

Optical systems found in sights, telescopes, and binoculars are compromises.

Inexpensive optical products often (must) have lots of undesirable compromises because high quality costs "big money" to both design and manufacture. Big money optics have few compromises, and often cost more than the firearm that they are mounted on.

You do not have to buy the very best or highest priced firearm optical sight to get a good quality product. However, cheap variable power scopes are usually of all around inferior quality to inexpensive fixed power scopes. If you have a cheap variable power scope, you best bet is to set it near its lowest power and leave it there.

P. S.-- To directly answer the question of post #1. The phenomenon you refer to is usually caused by something known parallax in the optical system. High end optical sights eliminate or greatly reduce parallax. In expensive variable power scope sights usually have lots of it. Using higher magnification usually aggravates parallax greatly in low price point scopes.

When the Redfield "3 to 9 power Rangefinder" (mounted on a Remington 700 with a heavy barrel) was near STATE OF THE ART for sniping in the late 1960's, operators were advised to determine the range to target using the variable power rangefinder feature; and THEN DIAL DOWN TO 3X TO MINIMIZE PARALLAX, AND SHOOT THE TARGET.