Originally Posted by maccid
x20 or x40 refers to the objective lense in millimeters correct. I take it this is the diameter of the lense. Correct me if I am wrong. What is the real difference? Does this let more light in or does it give a larger field of view?
On the front side of it the 3-9x20 would refer to magnifying the object 3 to 9 times more than the naked eye can see. Is this correct?
Yes objective lense is in millimeters. The higher the lense objective is (mm) the larger field of view you will have and I am pretty sure that you will have more light entering the scope as well. With the 3-9x20 you are right about the object magnification and the 20 is like trying to look at something through a straw if compared to a 40 or 50. I was pretty much schooled in scopes here at DHC by our helpful members. Welcome aboard!!!!!!