Inside the binos
Celestron has gone all out on the optics of the Echelon series. These binoculars use two prisms in each barrel. This makes it possible to keep the length reasonable; however, it also means that light must pass through multiple glass surfaces before it reaches your eyes, diminishing the brightness.
To address this issue, Celestron used the superior BaK-4 prisms — a high-quality type of glass found only in the best instruments — while most manufacturers use BK-7 type prisms, which are of lower quality. To determine which prisms are in your binoculars, hold them a few inches from your eyes and toward a bright light. If you see a squared-off field of view, BK-7 prisms are installed. Alternatively, the BaK-4 prisms in the Echelon produce a nice round field of view.
Celestron has also fully multicoated the optics of the Echelon binoculars for improved light transmission. The company used its proprietary XLT optical coating, which should provide superior viewing in low-light conditions, making them ideal for astronomical viewing.
Another thing that impressed me was the extreme eye relief. I wear glasses and have spent years perching them on my head every time I looked through binoculars. But while scanning the nearby mountains through this unit, I found that I could leave my glasses on. These instruments use individual focusing for each eyepiece. It requires a bit more effort up front, but results in crystal clear images.