Whats the difference between BaK4 and BK7 glass prisms?
Yes! Prism glass type is one of the first specifications you should check when purchasing a new binocular. Less-expensive BK7 glass is popular in budget binoculars, but is unsuitable for most uses because it causes dimming at the edge of the field of view. The result is a poor viewing experience. Only high-index barium crown (BaK4) glass prisms will provide acceptable performance. For example, a fully coated binocular utilizing BaK4 prisms can be a decent performer, but the same binocular with BK7 prisms would probably be unsatisfactory. All Garrett Optical binoculars utilize only the highest-quality BaK4 glass for their prisms.
