Technical Data
Glossary

How To read the numbers
Fixed Power Ex. 4x32

The first number of 4 indecates the magnification (You may call it power, also.), and the second number of 32 indicates the diameter of the objective.

   
Variable Power Ex. 3-9x40
The 3 to 9 scope magnifies the image from 3 to 9 times closer than the actual object through the eye. The last number of 40 indicates the diameter of the objective.
   

Objective Diameter
This is the diameter of the objective lens incorporated at the end of the scope. If the objective becomes larger, the more light will come into the scope for brighter view.

   

Parallax Adjustment System
This is the device that allows for binging the target image and reticle into focus together at various distances. JOL offers two(2) types of adjustment method.

Adjustment Objective(AO)
Side(Saddle) Focus(SF)

   
Reticle
Reticle is an aiming device incorporated in a scope and there are several types of reticles such as Mil-dot reticle, center dot reticle, cross hair reticle, four posts reticle, etc.
   
First Focal Vs. Second Focal Plane
If the reticle is placed in the first (front) focal plane, as the magnification is increased, both the target image and the reticle will get lager. This is particularly suitable for the scope with the range-finding reticle. If it is placed in the second (rear) focal plane, as the magnification is increased, only the target image will be enlarged while the reticle size remaining the same throughout the entire magnification the target image and the reticle will get lager. This is particularly suitable for the scope with the range-finding reticle. If it is placed in the second (rear) focal plane, as the magnification is increased, only the target image will be enlarged while the reticle size remaining the same throughout the entire magnification.
   
Mil-Dot
Mil stands for Milliradian, a Mil is one way an angle can be measured. It is equal to 1/6, 400 of a circle, and it measures 3.6 inches at 100 yards, or 36 inches at 1,000 yards. For long distance shooting, 1 Mil equals to 1 yard at 1,000 yards, or 1 meter at 1,000 meters.
1Mil equals 3.4348 minutes of angle (MOA) 1Mil in the reticle is the distance from the center of one dot to the center of the next.
Contrary to popular belief, the distance between the dots on the reticle measure .75Mil.
 
Windage and Elevation (click values)
These measurements indicate the distance traveled of the point of impact at 100 yards up, down, left or right. Example: if the click value is .25 and the elevation adjustment is moved four clicks to the right, then the point of impact change will be 1 inch higher on the target.
   
Focusing System at the eyepiece
This is the mechanism by which the scope is focused to obtain a clear, bright image.
   
Speed Focus
This is to promptly focus on the target without unlocking and setting the ocular. Also called as “rapid focus” or “fast focus”.
   
Eye Relief
This indicates the maximum distance between the eyepiece (ocular) and the eye to see a full field of view without straining the eyes.
   
Exit Pupil
Measured in millimeters by dividing the objective diameter by the magnification,
it is the bright circle of light viewable in the eyepiece. The larger the circle, the brighter the image. Example: 3-9 x 42 riflescope, (42/3) = 14mm at low power, (42/9) = 4.7mm at high
power.
   
Field of View
The viewable distance, from edge to edge, at 100 yards or meters. Also measured in angles of degree.
   
Tube Diameter
Most popular diameter is either 1 inch or 30mm. A large diameter tube collects and transmits more light to the eye.
   
Fully Multi Coated
All air to glass surfaces are coated with multiple layers to increase the amount of light that reaches the eye. JOL’s type “H”coat ensures over 95% light transmission.