First before getting into specific brands we should first look at the terminology to make sure even if you are a beginner you understand.
Terms such as field of view FOV, light transmission, magnification, Parallax, and so on...


Light transmission

Light transmission affects how much light makes it through the lenses inside of a scope and out to your eye. It is influenced by the type and quality of the glasses used, the anti-reflection coatings, and the control of glare inside the scope. This will be a large factor in the decision making process when it comes to budget this is the one thing at a higher in scope will have over its lower cost competitors. A Tasco Scopes just won't have the light transmission that a Zeiss Rifle scope has. This becomes a large factor with a high's zoom(magnification) the more magnification to more light you will need.

Objective lens


Is the front lens of the scope.The diameter of the objective (front) lens is in millimeters. Thus in "4x32," the "32" means that the front lens of the scope is 32mm in diameter. Note that this is the diameter of the lens itself, not the bell that contains it.
The diameter of the objective is important because it controls how much light the scope can let in, and ultimately transmit to your eye. The bigger the objective, the more light gets in the scope. The first number refers to the magnification so a Nikon 4x32 is a scope made by Nikon that has four times magnification and the objective lens is 32 mm in diameter.

Exit pupil

The exit pupil can be seen by holding the scope at arm's length and looking through the eyepiece. The pencil of light you see is the exit pupil.The diameter of the exit pupil is easily computed. Divide the diameter of the front objective lens (in millimeters) by the magnification of the scope. For example, take a typical 4 power rifle scope with a 32mm objective lens. Divide 32 (the diameter of the objective) by 4 (the magnification) and you get 8. 8mm is the diameter of the exit pupil for a 4x32 scope.

Field of view (FOV)

most scope manufacturers state how much linear area is encompassed by their scope's field of view at a certain range (usually in feet at 100 yards or meters at 100 meters). In any case, the larger the field of view the more area you can see through your scope.

Eye relief

The term "eye relief" refers to the distance from the scope's ocular lens to the eye. For .22 or a air rifles it can be as little as 1.5 inches, since recoil is not a problem. Scopes with short eye relief should never be used on rifles with large recoil such as a smug shotgun. And so on...Handgun scopes are normally fired at arm's length, and require a scope with extra long eye relief (in excess of 20 inches). We'll have to keep that in mind if you are a sports shooter using a hand gun.


Parallax

Parallax is also something that you are going to want to think about. For technical reasons, parallax can only be eliminated from an optical sight at one range, although it is not usually apparent in normal use unless there is something wrong with the sight. Leupold, for example, designs their center fire rifle scopes to be parallax free at 150 yards; rimfire rifle and shotgun scopes are designed to be parallax free at 75 yards. Some special telescopic sights, usually long range varmint or target models, come with an adjustable objective that can be adjusted to eliminate parallax at specific distances. High magnification scopes, or scopes for long-range shooting, where even slight sighting errors would be serious, should be equipped with a parallax adjustment.

Lens coatings

some lower end rifles have no coding on their lens at all. This means you will get a lot of reflection higher and have coding on the outside in the inside of the lens to minimize any reflections therefore creating a better light transmission. Some companies only codes are lenses on the outside. These are all deciding factors in quality and price of rifle scope. There are many different types of coatings as well which we will get into what we get into more specific brands of scopes.