[header] How to compare rifle scopes [title] Identify what you are looking at. When looking at two different scopes you must first manage to identify them. [step] Most rifle scopes have a marking composed of two or more numbers, separated by an x. the first is the magnification of the scope, and the second is the diameter of the objective (in millimeters). 
[substeps] For example a 4x28 scope has 4x magnification and and objective lens of 28 mm in diameter. Some scopes have a varying magnification, or zoom.