From Ron in Texas:
The Pentax CS 8x42 binoculars were purchased for a research project that required days of extensive hiking over rugged terrain. I chose the Pentax CS for their light weight, wide field of view and my own experience with Pentax products.
Two design flaws have come to light. First, the two intermediate eye cup detents are quite shallow, although my limited testing at these adjustments did not cause the eyecups to collapse. With the long eye relief, most people will use the eyecups fully extended, where the eyecups lock solidly. Second, the diopter adjustment, located just behind the focus knob, has no markings outside of center. This clip stop adjustment, while not a locking type, stays in place.
The CS focus from about 6 feet to infinity takes 1 1/4 turns, with good resistance. Nearly a full turn of the total rotation focuses from 12 feet down to the minimum. Depth of field, as compared to several other 8X bins, is quite good. The IP distance adjusts from 54mm to 74mm. These bins focus counter clockwise from close to distant. The light weight and fine balance make these bins a pleasure to hold even for long sessions. These bins work wonderfully with eyeglasses.
I could detect no chromatic aberrations or noticeable distortions. Contrast and color fidelity are excellent. The Pentax CS binoculars produce sharp, bright and vivid images across the entire field.
The Pentax 8x42 CS are impressive binoculars, which hold up in comparison to far pricier bins, even my Zeiss 8x42 FLs. Solid construction, great warranty, excellent optics and light weight make this binocular a best buy and highly recommended. These binoculars will see lots of field time.