Pentax 8.5×21 U-Series Papilio II Binocular


  • Aspherical Lens Elements
  • BAK4 Porro Prisms
  • Fully Multicoated Optics
  • Angle of View: 6°
  • Minimum Focus of 20″
  • Center Focusing
  • Twist-Up Eyecups
  • 1/4″-20 Tripod Socket

On Backorder

The compact and lightweight 8.5×21 U-Series Papilio II Binocular combines aspherical optical elements and BAK4 Porro prisms to deliver edge-to-edge image sharpness with a 51° apparent angle of view. The optical elements are also fully multicoated to provide a high transmission of light. With a 8.5x magnification and 21mm objectives, you obtain a notable magnification, insignificant image jitter due to unsteady hands, and a compact form factor. You can easily spot your targets with a wide 6° angular field of view and quickly bring them into focus with a center focus wheel. In addition to observing distant scenes, birds and game, the minimum focus of 20″ allows you to study in detail close objects like butterflies, animal footprints, marks or landscape features. To reduce image jitter while observing distant objects or for prolonged observations, you can connect the binocular to a tripod via an integrated 1/4″-20 socket. The binocular also features a 2.5mm exit pupil, a 15mm eye relief, an interpupillary and a diopter adjustments.

The binocular is very compact, lightweight, and features a single piece frame that houses objectives, which allows for a synchronized interpupillary adjustment. To accommodate eye glasses wearers, the binocular offers twist-up rubber eyecups. Also included are a carrying case, a neck strap, and eyepiece covers.

Optical Performance
Construction Details
Package Weight1.05 lbs
Package Dimensions5.8 x 5.4 x 2.8 in
Prism Type




Objective Lens Diameter


Angle of View

6° (actual)


346.5′ @ 1000 yd / 115.04 m @ 1000 m

Minimum Focus Distance

1.65′ / .50 m

Exit Pupil Diameter

2.5 mm

Eye Relief

15 mm

Interpupillary Adjustment

Not Specified By Manufacturer

Dioptric Correction

Not Specified By Manufacturer

Focus Type


Tripod Mount



4.57 x 4.33 x 2.1″ / 11.61 x 11.00 x 5.33 cm


10.2 oz / 289 g


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