That is a very informative article, especially for a neophyte such as me.
I have a question that is somewhat unrelated to the TRIAD. I have an early 1990s vintage Nikon 8x30 roof prism, green rubber-armored, individual focus binocular. With the individual focus, I can focus each eye separately once, and then the binocular stays in focus from short range to infinity. I always appreciated this feature because I can simply raise the binocular and instantly and clearly see what I am looking at without spinning a focus wheel.
What is it about this binocular that makes it able to stay in focus without adjusting for various ranges? I always figured it must have something to do with the individual focus feature, but I really don't know.
Also, why isn't this sort of binocular more popular, especially with hunters? It seems to be quicker and more fool-proof than spinning a focus wheel and maybe a diopter eyepiece. In fact, I can just glance at the settings by looking at the markings near the ocular lenses and know whether the bin has moved out of focus for my eyes. Typically, it doesn't, and so it is essentially always in focus.
What are the disadvantages to this type of binocular?
Thank you, and have a prosperous 2015!
