Originally Posted by edwardamason
Great Article. Could you please discuss more at length the 3;1 Ratio and the 5;1 Ratio and how the 5;1 ratio could be more versitle?
The ratio is just in reference to the range of magnification. Most scopes will be 3:1, meaning the highest magnification will be 3x that of the lowest magnification. Some manufacturers use 4:1 on some scopes (Nikon comes to mind) and some go up to 5:1 or 6:1 on some models.
The versatility I'm referring to in this article is in reference to the low mangification, close range capability in the same package of high magnification, longer range. You've got the ability to dial back to 2x or so for a very close-up shot and a wider FOV, yet you can go all the way up to 10x for shots out to a few hundred yards. You wouldn't want full 10x magnification for something under 50 yards, or vice-versa. You just get lots of choices with a wider range of mangification.
Of course, this wide range of magnification comes with a downside. A lot of scopes that utilize 5:1 and 6:1 magnification (2-10x50, 1-5x24s, 1-6x24s, etc.) are built in such a way that the glass in some of the lenses has to be curved to handle all the available powers in the entire range and still maintain edge to edge clarity, which can cause the pincushion/rolling ball/globe effect that some people are prone to seeing on these scopes. It was especially pronounced on the 2-10x models of the Minox ZA5, and you'll likely see it to varying degrees on most scopes with higher ratios.