Topics in this review and buying Pentax Papilio Binoculars
Pentax Papilio Binoculars
- Best close-up binocular
we've seen - check out those butterflies!
- Compact, 4.4 inches
long by 4.25 inches wide, weighs 10.5 oz.
- Encased in textured
dark green rubber for a secure grip and a nice feel
The word “Papilio” is Latin for “butterfly” and the name tells us that the Pentax
Papilio binoculars were designed specifically for looking at butterflies. What makes
the Papilio a butterflying binocular? The short answer is: the amazing close focus.
Pentax lists Papilio binoculars as having a minimum close focus of just 19-20 inches
(or about 0.5 meters). When we first received the Papilios, we tried it out and
in disbelief tried it again! We easily got down to 18 inches with no field collapse
and remarkably crisp image quality, a close-focus capability that is unmatched by
any other binoculars. If you ever want to get close to something with a binocular,
this is the one! The key concept with Pentax Papilio binoculars is versatility.
Papilio binoculars are great for viewing anything from butterflies to birds to sporting
events and concerts. With their compact, lightweight design and their ability to
double as a binocular/magnifying glass, the Papilios are a fabulous binocular for
Size and Weight
Papilio binoculars are a reverse porro prism design offered in 6.5x21 and 8.5x21
models. The “reverse” means that unlike a conventional porro prism design, the objective
lenses are closer together than the ocular lenses. Like most reverse porro prisms,
Pentax Papilios are very compact, being just 4.4 inches long by 4.25 inches wide,
and weighing just 10.5 oz. You basically never even notice that these are around
your neck, even after extended hours in the field. Papilios are made with BaK-4
glass prisms, aspherical lens elements, and fully multi-coated optics to maximize
light transmission and minimize distortion. While they do this with admirable success,
the truth is that they are still not a binocular to use in really limited light.
This isn’t really a revelation though. Even with the world’s finest glass, 21-mm
objective lenses are physically limited in light-gathering power, and even with
the most efficient light transmission possible, they won’t be blindingly bright.
In most light conditions, the brightness of the Papilios is more than sufficient
for its primary intended use.
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The focus knob is centrally located and less than half an inch wide, but it is raised
enough above the prism housing to be easily accessible. It is made of deeply-ridged,
hard plastic and turns with great ease, making for extremely precise focus. We soon
noticed that the Papilios take fully 3.1 turns of the focus knob to go from minimum
close focus to infinity. There is a really good reason for this. To achieve that
incredible 18-inch close focus without field collapse, Pentax designed an adjustment
for parallax that is, as far as we know, unique. When focusing, the objective lenses
move simultaneously on non-parallel tracks. When you focus on something further
away, the lenses move toward your eyes and separate from each other; as you focus
on closer objects, they move away from your eyes and converge on each other. That
they do so with such ease and smoothness is nothing short of remarkable. You’ll
have to pardon us, but to optics geeks like us, this is just really cool!
With the 6.5x Papilio, the field of view at 1000 yards is a very respectable 393
feet, while the 8.5x model is a bit more restricted at 315 feet. In fact, compared
to other mini-binoculars, the Papilios have a relatively large field of view. We
measured the interpupilary distance range of the Papilios at 55 - 74 mm. What does
that mean to you? The interpupillary distance is how far apart your pupils are.
For a binocular to be comfortable, the ocular lenses must be positioned directly
over your pupils, and the broader a range offered by a binocular, the greater the
probability that you can do this. Mini-binoculars often lack sufficient range to
be comfortable for all users but the Pentax Papilios are well designed in this regard.
The eye relief claimed by Pentax is a relatively short 15 mm, though this amount
of eye relief is common in reverse porro prism binoculars. Here we found something
interesting: we used the Papilios with the eyecups fully extended with comfort.
We’ve had had trouble with similar designs from other manufacturers that claimed
equivalent or longer eye relief. Whatever the cause of this discrepancy, the eye
relief of the Papilios was quite adequate.
Optical and Mechanical Performance
The Papilios show only a little field curvature with a slight tendency for straight
lines to bow inward at the outer edges of the visual field. We did note a bit of
blurriness at the outer field edges. We saw virtually no color aberration even on
brightly-lit, high-contrast objects, which is fairly remarkable. We detected no
color bias under any light conditions. On the Papilios, the diopter adjusts with
a rotating ring on the right ocular tube. The ring turns with relative ease through
a series of closely-spaced click-stops. Thus, while not a locking mechanism, any
selected position is stable. A raised line on the ring lines up with a raised dot
in the rubber armoring of the ocular tube to indicate the position for equal eyes.
The eyecups adjust with a helical twist mechanism through three positions: fully
in, fully out and halfway between. Each position is stabilized against collapse
by detents. These are fairly elegant refinements on a binocular of this class.
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Pentax used an interesting structural design feature: instead of a single central
hinge, the Papilios have two “wings” that hold the ocular lenses and attach to the
main chassis by separate hinges. Moving either wing causes the other to move the
same amount. The body is encased in textured dark green rubber armoring that imparts
a secure grip and a nice feel. The ocular wings have shallow thumb grooves, as does
the bridge structure between them. There is a tripod attachment site on the underside
of the body. This feature would be useful if one were studying a particular object
or creature for a long period of time or trying to sketch from nature.
The thin nylon web strap has plastic attachments that snap into recessed grommets
in the surface of the wings. This attachment allows the entire assembly to rotate
around the attachment point, for greater user comfort. The strap attachments fit
so closely against the body of the binocular that they avoid chafing against the
hands, a frequent problem for other mini-binoculars. The rainguard is a hard plastic
pair of cups held together by a bridging section. The fit over the soft rubber of
the eyecups is tight enough that they do not dislodge easily so the rainguard won’t
get knocked off inadvertently. There are no lens caps for the recessed objective
lenses. Also included is a padded black case, which is large enough to hold the
binocular with the eyecups extended so they don’t have to be folded down before
being put away. The binocular strap fits out the sides of the Velcro-closing flap
so that binocular and case can be worn over the neck or shoulder. The case also
features a belt-mounting loop on the back for convenient deployment at the waist.
This helps because, without a strap for the case itself, you would have to hold
the case if you carried it into the field.
All the great design and remarkable engineering of the Papilios comes at a surprisingly
low price: the 6.5x model sells for just
while the 8.5x model is only
Though the Papilios were optimized primarily as butterflying binoculars, their versatility
makes them ideal for a wide variety of other activities. They are easily tucked
into a glove compartment so you can have them everywhere you go. Their smooth operation
and light weight makes them easy for young children to use. Their ability to function
like a hand-lens gives them an extra dimension in the field. For up-close study
of butterflies, birds, bugs, blooms or whatever, Pentax Papilio binoculars are hard
Pentax Papilio Binoculars
- current price and availability