Introduction:
The most superior in focusing at objects real close by are the Apex 8x32 Waterproof Super Close Focus Binocular by Alpen, the Columbia Backcountry 8x25 Pocket Roof Prism Binocular and the Eagle Optics Ranger SRT 8x32 Binocular (compact binoculars), as well as the Zumell Signature 10x42 and Hawke Endurance Close Focus 10x42, both of which are normal size binoculars. Their close focus distance is less than 4 feet(1.2 meters), which is unheard of and makes them perfectly fit for observing insects like butterflies and dragonflies.
If searching for words to describe the special ability of a binocular to focus this close, how are you going to describe what the Pentax Papilio can do, with its ability to get an object as close as 18 inches (less than half a meter) in focus?
The problem with focusing really close:
Binoculars are actually two telescopes working in unison. Each telescope delivers its own image to the viewer. Consequently, two different images reaches the eyes of the viewer. However, in his mind these two images are integrated into one – as long as viewing something not up close. However, the closer the object, the more difficult it gets to integrate the two images, until it is not possible anymore. The closest distance at which the two images integrate in a natural way is where the close focus ability of most binoculars is set. This could come down to as close as 1 meter in the case of the binoculars mentioned above. Even though this is very impressive, the two images are not completely integrated as one.
How did Pentax solve this problem?
Pentax invented a total new technology known as CLOSE : Convergent Lens Optical System Engineering. With CLOSE this Pentax binocular does not consist of two telescopes joined together to make one pair of binoculars; the objective lenses are placed in a solid housing separated from the eyepieces. Adjusting the barrels to fit your eyes has no impact on the position of the objective lenses, as in the case of all other binoculars.
For focusing you use the focus knob on top of the instrument as in all binoculars. Focusing is done by moving the lenses closer or further apart from one another and not, as in the case of other binoculars, by moving the lenses closer or further away from the eyes of the viewer.
Since the objective lenses are placed inside a solid housing, they start moving towards one another when the viewer focuses on an object. Using an ordinary pair of binoculars, focus on an object at a distance – no problem; now get closer; still no problem; now real close by and you’ll see that the two images do not overlap completely. Then do that with the Pentax Papilio; no problem at all! Since the two lenses converge on each other, it is possible for the two images to overlap perfectly and that happens right up to 18 inches. So you can still see the object with both eyes as one integrated image – and that happens without any eyestrain!
As you focus closer and closer, each eye's line of sight converges with the other's, so that both eyes are always looking at the same thing.
Dimensions:
The Pentax Papilio is a compact binocular of the “reverse porro” type, 4 inches long and 4.5 inches wide, weighing only 10.5 ounches. The size of the apertures is 21 mm.
Different models:
Two models are available: The Pentax Papilio 6.5 x 21 and the Pentax Papilio 8.5 x 21.
Different applications:
“Papilio” is the Latin word for “butterfly”, so Pentax clearly developed this instrument as a specialist instruments for super, super close viewing of insects like butterflies. As far as this is concerned, it is in a class of its own. However, it can be used for viewing objects further away as well, but then the limitations of the small objective lens do come into play.