Do you really need an expensive 6x zoom scope?
When we buy a scope, we want a scope that is clear, has good light transmission, accurate and repeatable turrets etc. These are the features we will not be talking about. The one single feature we talk today about here is zoom ratio. In deciding the zoom ratio we want, we usually first decide what is the top end of the required magnification. That is dictated by the longest shot we intend to make. We then consider how close to our target we will also use the same scope. For hunting people tend to want something between 2x to 4x at the low end.
A common practice of scope manufactures today is separate product lines by their zoom ratio. Leupold and Bushnell are such examples. Leupold's VX3 line has 3x zoom ratio, VX5 5x zoom ratio, and VX6 6x zoom ratio. Bushnell Elite 3500 line has 3.5x zoom ratio, Elite 4500 has 4.5x zoom ratio, and Elite 6500 has 6.5x Zoom ratio. Usually you pay a little more for a scope with higher magnification within the same line, but you pay a big premium for scopes of a high line. For example, price difference between VX3 2-7, 3-10, 4.5-14, and 6.5-20 are incremental, but when you go from VX3 to VX5 you pay big, when you go from vx5 to vx6 you pay bigger yet again.
Sure, there are additional features such as side focus, zero stop, high speed turret etc as you go up product line. But you mostly pay for the optics in the zoom part. Between VX3, VX5 and VX6, there are some image quality differences, but they are not big (at least so based on the reviews).
Put this another way, you pay a lot more money when you go up a product line for comparable magnification. For example, VX3 4.5-14 is about 1100, VX5 3-15 is about 1700, VX6 2-12 is about 2700 and 3-18 is about 2900. Aside for the extra features, you are paying a lot of money for the low end magnification. Basically, how low it can go.
A wise person has said (in another forum) that no one actually want lower magnification. People want zoom down because they want wider field of view. This is important and there is an important distinction between field of view and zoom magnification. Many scopes do not actually give you wider field of view when zoom down. Instead, you simply get a thicker black ring around you image. This is known as the tunnelling effect. In other words, when you have tunnelling, you are not getting wider field of view, the extra lowering of magnification at the low end is meaningless.
Even some very high-end scopes suffer from this problem. See below the extract of a review of the super high end S&B PM II:
"Low and behold, it is true. What is tunneling? On this 5-25x PM II, it happens between about 5x to just a tad over 7x. The magnification changes as normal, growing or shrinking what is viewed through the sight picture, but what happens is that the field of view remains exactly the same, it does not shrink the field of view when going from 5x to 7x. It is hard to explain, but when looking through the scope, it is like the entire scope image is moved away from the user, or closer to you. If you look at our side by side reticle pictures above, you can kind of see it. Look at the edges of the scope view in the 5x picture on the left compared to the edges on the 25x picture on the right. It is like the internal erector tube is moved away from you and it seems like you can see the edges of the tube itself. It is odd, and we measured the field of view to confirm what we were seeing and verified that it did not change from 5x to 7x. Above 7x everything is great and as you would expect."
Basically, for all intended purposes, PM II is not 5-25 5x zoom ratio scope, it is a 7-25 scope, less than 4x zoom ratio. In this regard, Leupold is actually one of the more honest scope makers on the market, their indicated field of view usually correspond with reality.
This is important because people are paying a lot of money for that extra zoom ratio. if one only needed to use the 25x magnification, one would not have bought this scope. There are many scopes with less zoom ratio and perform very well as 25x magnification.
It is a pity that this issue is not considered more by the scope makers and the shooting industry generally. With AR15, one alternative solution is to have iron sight on the side going 45 degrees from the scope. Basically if you want to aim the iron sight you just tilt the gun by 45 degrees on the side and you get full field of view of your natural vision.
Another AR only solution is to have a tiny iron sight on top of the scope. like this . I think it should work well with hunting scopes too. Hunting scopes tend to be far longer, and would provide longer aim aligning distance making it more accurate (not that accuracy for close distance hunting is required). 20x scopes are usually between 36 to 40 cm long, that is how much distance you would have between the front and rear sight on a 16 inch barrel (if both sights are installed on the barrel). If implemented I think you can get away with using a light weight 6.5-20 scope and a pair of light weight iron sight that would cover you the shooting situations as a very expensive and heavy 2-20 scope would.
