Pentax SP 10x50 WP

The Pentax SP 10x50 WP is an astronomy binocular that happens to be sold in the general optics aisle. Expert reviewers rate it very highly recommended for stargazing, and the praise is specific: pinpoint stars with no secondary spectrum, very little ghosting on the moon and bright lights, and measured light transmission around 85% - real performance, not marketing. Its party trick is structural: unusually for a porro prism design, it focuses internally, which is what lets Pentax fully waterproof and nitrogen-purge it. Owners describe it as the natural step up for someone who has outgrown a budget 10x50 and wants a significantly better instrument without leaving the value zone.

In use, it's a deliberate, stationary-viewing instrument. The image is sharp and bright with excellent contrast, and forum users who compared it directly found it sharper across the field than the Nikon Action Extreme, though center sharpness sits a slight notch behind premium porros like the Pentax ZD. The 20mm eye relief is about as good as it gets for eyeglass wearers, the focuser locks so your infinity setting survives transport, and the aluminum chassis with recessed objectives is built like field equipment. The trade-offs cluster around agility: a narrow 5-degree field, a stiff slow focuser, 18 ft close focus, and 37.4 oz of weight that has reviewers reaching for a tripod. The accessories - loose caps, thin case - are a running complaint.

Buy it for what it is: a stargazing and fixed-viewpoint binocular for astronomy enthusiasts, cabin owners, and coast watchers, especially anyone who wears glasses. Against the Nikon Action EX 10x50 it trades field width for edge sharpness, eye relief, and true sealed-porro construction. Birders should look elsewhere - the slow focus and narrow field fight everything birding demands. But pointed at the Pleiades from a lawn chair or a tripod, it delivers a level of optical cleanliness that embarrasses its $229 price.