The Pentax Papilio (6.5 x 21 and 8.5 x 21) binoculars are not only excellent pocket binoculars; they are also in a class of their own as far as close focusing is concerned. The best super close focusing binoculars can focus as close as 3.3 – 4 feet (1 – 1.2 meters), which is really exceptional and makes them perfectly fit for observing insects like butterflies and dragonflies. The Pentax Papilio Binoculars, however, can focus as close as 18 inches (46 cm). So if you’re looking for a pocket binocular with exceptional close focus ability, you have to consider one of the Pentax papilio models.
Why is super close focusing such an issue for manufacturers?
For all binoculars, the closer the object on which the viewer is focusing, the more difficult it gets to integrate the two images coming through the two separate barrels of a binocular, until it is not possible anymore. Pentax invented a total new technology known as CLOSE : Convergent Lens Optical System Engineering. With this mechanism the objective lenses have been integrated into a solid housing separate from the barrels in which the eyepieces are found. The instrument focuses by moving the objective lenses not further or closer to your eyes, but by moving the lenses closer or further apart from one another. Since the two lenses converge on each other, the two images overlap completely up to as close as 18 inches. So you can still see the object with both eyes as one integrated image – and that happens without any eyestrain!
Lenses and coatings: Fully multi-coated, with high quality Bak4 prisms (ensuring better light transmission at the edges in dim light). Considering the fact that the objective lenses are merely 21 mm, the level of sharpness, brightness and contrast is truly impressive. So the optics of the Pentax Papilio binoculars are way beyond what can be expected from a binocular in its price range (around $100-00).
Weatherproofing: Unfortunately these binoculars are not weatherproof.
If you’re into viewing butterflies and have to have a pocket binocular with super close focus ability, you have to consider one of the Pentax papilio models.