The Pentax UCF X II 8x25 are compact, almost pocket-size binoculars you can take with you almost anywhere. The compact size is ideal for keeping the binoculars readily available in your car, tucked into your luggage or sitting on the bookcase next to the panoramic window overlooking your backyard.

The UCFX II uses an inverted porro prism design with fully multi-coated BaK4 glass. The advantage of this design is its compactness; the disadvantage is that the prism mechanism cannot be sealed, so the binoculars cannot be made waterproof.

The multi-coated optics enhance light transmission and produce very good brightness for compact binoculars. The 1000x324-feet field of view is quite good for small binoculars, particularly in a design where the small 25mm objective lens is actually recessed into the binoculars' body. At the other end, the eyepiece has an eye relief of 15mm and includes eyecups that can be positioned at full extension or halfway out, to adapt to different users.

The UCFX II employs an unusual diopter adjustment system that we found both easy to use and easily able to lock in the adjustment. A small knob is located in the center of the binoculars, between the eyepieces. When you push the knob it pops out; you can then rotate it to adjust the diopter setting. When you have the diopter configured to your satisfaction, pushing the knob back in locks the setting in place. This diopter system is easy to adjust, and doesn't slip out of adjustment during use. This was a pleasant surprise, because a common complaint with binoculars is that either the diopter is difficult to adjust or it slips out of adjustment too easily.

The close focusing capability is a remarkable 6.2 feet. The tradeoff is a slow focusing system that requires the focus knob to make three full rotations to move from 6.2 feet to infinity. The UCFX II is not ideal for birding or other uses where you need the ability to change focus quickly.

Compact binoculars always require a tradeoff between features and performance, and size. Pentax made good choices in this case. The Pentax UCFX II is one of the better compact binoculars available in its price range.


Pros: Lightweight and small, close focusing, good diopter adjustment system
Cons: Slow focusing system, non-sealed prism design, not waterproof

Warranty
lifetime, limited