The Kowa Genesis 8.5x44 Binocular marks the peak in Kowa's line of roof prism binoculars. It is engineered for the utmost in performance, viewing quality and durability. This binocular is an optical luxury worth every penny as it easily holds its ground with other brands of premium sport optics.
The 8.5x44 binocular mates Kowa's own Prominar ED glass to minimize chromatic aberration with C3 optical multi-coatings that allow an unheard of 99% transmissivity of each element between 400 and 700 nm, a feature that is very helpful when spotting birds. Most other units competing in the Genesis' range average 95%, and as such, the Genesis series binoculars certainly stand out from the crowd.
All Genesis series binoculars feature a lightweight yet extremely rugged magnesium frame that is the foundation of the waterproof and fogproof body. Optically, the unit can focus down to an amazing 5.5' and the boost in objective lens size from a more common 42mm to 44mm provides a clear view that is 10% brighter. Internal focusing aids in keeping the overall operating size from becoming unwieldy.
Objective Lens Diameter
Angle of View
367' @ 1000 yd / 121.84 m @ 1000 m
Minimum Focus Distance
5.58' / 1.7 m
Exit Pupil Diameter
Not Specified By Manufacturer
Not Specified By Manufacturer
Not Specified By Manufacturer
5.4 x 2.5 x 6.5" / 13.72 x 6.35 x 16.51 cm
2.09 lb / 948 g
Padded Ballistic Nylon Case with Strap
Binocular Suspender Strap
Neoprene Neck Strap
Tethered Push-on Objective Lens Caps
Limited Lifetime Warranty
Kowa 8.5x44 Genesis XD44 Binocular
by Holger Merlitz
While the price tags of current high-end binoculars seem to increase
faster than ever, it becomes more interesting to take a look at the
second quality line offered on the binoculars market. Fortunately, there are a couple of
new models coming up these days, and the present review is going to
compare three samples of the price range from 500 to 1000 Euro.
I have selected these models because they they seem to offer a particularly
favorable performance to price ratio, and since they cover a wide
price range, they do, quite naturally, differ in their performance.
But apart from their relative performance, it will also be
instructive to compare them with the high-end binoculars, and to judge
to what extent the much higher prices asked for the prime division are
Along with the 10x42, the 8x42 class is highly popular among bird watchers
and other nature lovers. Here, the lack of high magnification is compensated
with a larger exit pupil beyond 5mm, which makes the binocular suitable for
low light observations. Additionally, the 8x power can still be managed in
hand held mode, since a shake-free image is achieved without the need of
any support by cumbersome tripods or monopods. Last not least, these
binoculars, if well designed, offer fairly wide fields of view beyond
7 degs which makes it easy to survey large areas and to follow moving
Fig. 1: The Kowa Prominar XD
In recent years, Kowa has established a line of spotting scopes which is
highly regarded among bird watchers. With the new quality line of binoculars,
called the Prominar XD (in US: Genesis), which currently contains a 8.5x44 and a
10.5x44, Kowa is intending to challenge the high end contenders of Zeiss, Leica,
Swarovski and Nikon. The specifications are impressive: Objective with
4 lens-elements (two of them made of XD, i.e. extra low dispersion, glass), a 5
lens-element ocular, and the Schmidt prism system contains a dielectric reflective
surface with 99% reflectivity. A close focus of 1.7m is specified, and there
exists a filter thread at the objective end which takes standard 46mm
photo filters. The entire construction is embedded into a
magnesium alloy frame, is fully water proof and nitrogen filled. This binocular
is produced in Japan, and its price is slightly exceeding the 1000 Euro line.
Fig. 2: The Meopta Meostar B1
Meopta is a factory located in the Czech Republic. The Meostar B1 is
a recent development, located in the higher middle class price segment.
The stubby and compact body contains 4 lens-element objectives and oculars.
On the Meopta web-page, I have found a sketch which indicates another
lens just in front of the prism-entrance, most likely serving as
a field flattener.
The body is made of aluminum, filled with nitrogen and fully water proof.
The Meostar B1 line currently contains a 7x42, 8x42, 10x42, 7x50, 10x50
and 8x56. The price of the 8x42 is between 850 and 900 Euro.
Fig. 3: The Vortex Razor
Vortex is is an optics dealer located in Middleton, Wisconsin, USA.
The Razor is a new model, based on the open hinge
design which was first introduced by Swarovski. Although the
imprint reads 'Made in Japan', several independent sources have claimed
that this binocular might be assembled in China while adhering to
Japanese quality control. The objective lens
is touted to contain XD glass, the prism system contains a reflective
silver layer, and the aluminum/polycarbonate chassis is fully waterproof
and filled with argon. To my best knowledge, the use of argon as a
dry and inert filling does not offer any significant advantages over
nitrogen. Interesting are the eye-cups which can lock at any distance
between 1 and 16mm, and which are extremely convenient to use. The
Vortex also comes with interchangeable eye-cups which feature a shield
to prevent stray light from the side, but these eye-cups have got a
fixed ocular distance. The Razor line contains the 8x42, 10x42, and
the 8.5x50, whereas another 10x50 and 12x50 are planned. The 8x42
is a classical medium quality-range binocular and available for
about 500 Euro.
Fig. 4: The Meostar, Prominar and the Razor
The following table summarizes some of the specifications of the
||of view (deg)
||of view (deg)
Angle of view: The Meostar and the Razor both offer a reasonably
wide 63 degs. of apparent field. The Prominar, with 59 degs., is
not far behind. For comparison: The 8x42 Zeiss Victory FL offers
62 degs, the Leica 8x42 Ultravid 60 degs., and the Swarovski
8.5x42 EL 63 degs.
Image sharpness: All quality binoculars offer a sharp and crisp image
at least near the central region of the field, and there are rarely
any significant differences discernible. In this matter, the Kowa
Prominar is surely special, since contrast and definition of its image
are outstanding. I have observed power lines at a distance of 1/2 km
in front of white clouds, and the cables were,
through the Meopta and the Vortex, imaged as very fine,
grey lines. This implies a high resolution of these
binoculars. The Kowa, however, displays the same lines in deep black
color, indicating an exceptionally high degree of contrast. This
is most likely the result of an improved suppression of chromatic
aberration. Towards the edge of field, the star test reveals
the first signs of blur about 75% (radial) from the center.
Near the edge, however, this blur remains moderate, so that under less critical
viewing conditions under daylight one may sometimes get the impression of
the Prominar being sharp almost to the edge.
A similar fraction of point-like stars is also offered by the Meopta,
which has also got a somewhat larger field of view. Near the edge,
stars display a little more deformation due to astigmatism, but not too
excessively so. The Vortex is somewhat behind, with about 65%
of point-like stars it is just average. The edge sharpness of
both Kowa and Meopta are on Leica and Zeiss level, only the
Swarovski 8.5x42 EL, which is almost reaching 90% of radial field
with point-like stars, is clearly superior. Regarding contrast, the Kowa
is definitely challenging the best of the best.
Image color: A completely neutral image is produced by the Kowa.
The Meopta and the Vortex both display a slightly warm image tone.
It is not adequate to talk of an image tint, however, since the bias
towards yellow is tiny. Still, some professional birders may be
asking for the perfectly neutral color rendition which is offered
by the Kowa. Additionally, the Kowa is also offering threads at the
front end of the objectives, where standard 46mm photo filters can
be attached. This feature allows for further variations, depending on the
viewing conditions. For example, polarization filters may be useful
when observing a shiny water surface, or yellow filters may be used under
bright sun, in particular over snow, in order to reduce the eye-strain.
Rectilinear distortion: The Meostar is showing the usual degree
of pincushion distortion. As was discussed here, this distortion is useful in order to compensate for
the globe effect when panning over wide areas or when tracking a
moving object. In fact, the background is moving very smoothly when
the Meopta is used to scan wide areas for interesting objects.
To the contrast, the Kowa has got a very low degree
of distortion, and while panning around, the globe effect is clearly
visible. The Vortex Razors correction is in between both extreme
cases; a straight line displays a little inside-bending when shifted near
the edge of field, indicating a small amount of pincushion distortion,
and the same binocular also shows a mild degree of globe effect.
This description shall not imply any judgment: It is a matter
of design philosophy, whether one prefers to correct for pincushion
distortion (and hence tolerates the globe effect) or vice versa.
Leica, Zeiss and Swarovski employ a pincushion distortion at
the same level as does the Meopta. The Nikon HGL is, in this regard,
rather similar to the Kowa.
Stray light: Stray light is generated whenever light finds its
way through the instrument into the eye through an unforeseen path,
for example as a reflex at the internal tube, a prism or lens edge.
Top class binoculars often differ from their medium range competition
in their ability to suppress stray light under difficult light
conditions. In this discipline, both the Kowa and Meopta show
an excellent level of performance. Even the Vortex, though
somewhat behind both competitors, suffers from stray light only under
adverse conditions, and the stray light intensity remains low and
does never dramatically reduce the contrast of the image. At least
the Kowa and Meopta are here fully competitive with the high end
Ghost images: If, at night, a bright object (street lantern, moon) is
positioned into the field, reflections on the air-to-glass surfaces
take place, which can lead to multiple 'ghost' images of the
light source. A successful suppression of these ghosts indicates
a high quality of the anti-reflection coating. Here, all three
competitors display a high degree of resistance against ghost
images. It appears that the Kowa performs slightly better than
both Meopta and Vortex, but there is another effect which is
characteristic for roof prisms: As a result of diffraction at the
roof edge, a bright point-like source is producing a single
'spike', and since both prisms (left and right tube) are
oriented under different angles, both spikes form a cross-like
structure when the light source is of sufficient intensity.
The intensity of these spikes may be related to the
accuracy to which the roof edge is cut, and hence it differs from instrument
to instrument. In the present test, the Kowa displayed spikes
of marginally higher intensity than its competitors, and this fact
eliminates its advantage of having the most effective coating.
During an earlier comparison, I have seen the same spikes through
a Leica Ultravid and a Swarovski EL, but through the Zeiss Victory FL
these spikes were less intense.
In such a test, however, only Porro binoculars are able to deliver a perfect
image, and I have experienced that kind of perfection with
the Swarovski 7x42 Habicht.
Low light performance: Since all three competitors have got
roughly the same exit pupil size, and all of them are using
high quality coatings and hence may not significantly differ
in their overall transmission, major differences in their
low light performance should not be expected. In fact, my
test did not reveal any significant differences here. The
outstanding contrast of the Kowa under daylight conditions is
apparently not of the same efficency under low light conditions.
I suspect that all three contenders perform about as good
as a quality 8x42 binocular can do under low light.
The most important features are quickly summarized: All three
binoculars are fully waterproof, protected with a durable rubber
skin, have got a long eye-relief for use with eye-glasses and
a short close focusing distance (Kowa: 1.7m, Meopta: 3m, Vortex: 2.5m).
When comparing their weights with the current high-end
(Leica Ultravid: 790g, Zeiss Victory FL: 775g, Swarovski 8.5x42 EL:
820g), it is obvious that the lower priced binoculars are more heavy,
and the weight difference is of the order of 100-200g. The objective
covers are attached and cannot be lost in action. The central
focuser of the Razor is working smoothly and precisely, but the diopter
correction, activated after pulling out the focusing barrel,
appears too stiff so that I can hardly operate it with a single
finger. It is interesting to note that the Razors focuser is turning
reversely: A clockwise turn is focusing near, usually it is
the other way around.
The Prominar has got a huge focusing barrel which is easily accessed,
and the diopter setting is done with a ring near the right hand ocular.
With my sample,
this ring had got a little amount of mechanical play which took
away a bit of the focusing accuracy. The central focuser of the Meopta
is somewhat smaller, but coated with anti-slip rubber, and working
with high precision as well. I find the Meoptas short body most
comfortable to hold and to operate and I do in fact prefer it to the open hinge
construction of the Razor or the long body shape of the Kowa. On the
down side, the Meostars eye-cups cannot be locked at any intermediate
positions. Fortunately, they operate with a considerable friction
and won't easily turn without intention. The Kowa has got
4-stage interlock eye-cups, and the Razor can even be locked at any
distance. There is also a distance scale which helps to find the
optimum setting - an excellent idea which should become a standard
for any new binocular design.
Another excellent feature is the Kowas filter thread in front of
the objectives, where 46mm filters can be attached. Kowa might
consider to offer screw-in lens hoods as additional gadget for
use under most difficult light conditions. Altogether, the built
quality of the test candidates is on a pleasantly high level,
but it is not possible to judge whether or not they would be on par
with the absolute high end. It would perhaps take several years
of serious use and abuse to figure how well their constructions
can survive in the long run.
The following table is supposed to summarize the above observations.
The best performing binocular gets three points,
the following contenders two and one, respectively. In case several
of them perform equally well, the scores are averaged.
The 'final score' is the sum of the individual scores and
is intended to serve as an orientation only.
Altogether, the Kowa Prominar XD does without any doubt deliver the best optical
performance. Most of all it is the outstanding contrast, a result of the
successful elimination of chromatic aberration, combined with a top
class stray light protection and a perfectly neutral image tone, which
make it a serious competitor to the high-end. I think it is not
so much the optical quality of its image which would separate the Kowa from
Zeiss/Leica/Swarovski, but rather its higher weight and a
couple of percent smaller field of view. Everybody who is considering
to spend a lot of money for a top class binocular has now got the
alternative to save several hundreds of Euro and to choose the Kowa, thereby
carrying 150g extra weight and sacrificing a little bit of field of view.
The Meopta Meostar B1 is an excellent performer within the sub-1000 Euro
class. There was no weak point, it displayed a very balanced performance
over the entire range of different tests. Its image is pleasantly wide
and plane, with a fairly high level of edge sharpness, which makes it
an interesting candidate for astronomy. Throughout the test, this binocular
was never suffering any significant stray light, and its body shape
promotes a stable and steady hold in free hand mode. I would rate the
Meostar above the Docter 8x42 B/CF, in
particular because of its superior stray light suppression.
The Vortex Razor can be bought for 500 Euro, half the price of the
Kowa, and not surprisingly it is a little behind its competitors
in some of the disciplines. But for its price tag, it serves as an excellent alternative
for those who want to invest into a medium price range binocular and
who are looking for the best performance available in that class.
The Razor is of very good built quality, has got a state of the art
coating and offers a pleasantly wide field of view, although the
image quality is diminishing towards the edge. Altogether this is
a very good all around binocular which should be able to survive
even the harder outdoor adventures without any problems.