Kowa SV 10x42 Binoculars Review

When Kowa first announced that they would be introducing a more affordable line of binoculars manufactured in China into their range, I did wonder that by doing so they may be cheapening their brand that has a very high reputation, especially amongst serious birdwatchers. Then, when I first saw them at the British Birdwatching Fair my worries were eased a little as whilst they may be lower spec than their top of the range Kowa Genesis Binoculars, they still looked to be a reasonably high quality pair of optics and obviously aimed at people who still want a good pair of binoculars, but can't justify or who can't afford to spend the amount needed for their flag ship models like the superb Kowa Genesis 10.5x44 XD Binoculars that won my award for the overall best binocular of the year in 2010.

So I asked them if they would be interested in sending me a few pairs to review and below are my thoughts on the Kowa SV 10x42 Binoculars:

The Body

Unlike the current trend of open-hinge designed binoculars, Kowa have stuck with a more traditional design on these, except for the rather long barrels. This does obviously add to the length of the body, but doe's also make a nice large area for you to grab hold of them securely.

On the underside of the body there is a wavy depression in the rubber armor on each barrel, which not only adds to the styling, but is placed in such a way as to also help with grip and your thumb placement. It is a little different, but is rather like the thumb indents that you find on many other binoculars.

I also really like the fact that the objective lenses are set quite deeply within the body (about 6mm) - which will help protect them when the lens caps are removed.

Weight
Weighing 23.6oz (670g) these are up there with some of there lightest pairs of full sized binoculars that I have ever reviewed. For comparison take a look at these other similar sized optics:

• Steiner 10x42 SkyHawk - 25.4oz (720g)
• Minox 10x42 BV's - 27.5oz (780g)
• Swarovski 10x42 EL's - 27.5ozs (780g)
• Leica 10x42 Ultravid HD - 26.5ozs (751g)
• Zeiss 10x42 Victory FL - 26.8ozs (760g)

You have to be a little careful when comparing weights as it can sometimes be misleading as very light binoculars are sometimes made of much weaker and inferior materials (like plastic). However this is not the case with these - take a look at the section on build quality below.

Dimensions
The dimensions of this 10x42 Kowa SV binocular is 6.8in (17.2cm) x 5.0in (12.8cm) x 2.2in (5.6cm), which as I mentioned earlier makes them a little longer than most full sized binoculars with objective lenses of about 42mm. Other than that their dimensions are fairly standard. To me they were comfortable to hold and well balanced, with the longer barrels having no noticeable adverse effects. The focussing wheel was easy to reach and turn without having to adjust from the standard grip when holding them up to your eyes.

Best Binocular Rating for Body Stats: 8/10

Build Quality
I have not been able to find out exactly what the frame of these SV's is made from, which is a shame as I do wonder what they used to make them so light. As mentioned earlier, very light binoculars are sometimes so light because they are made of cheap materials, but these feel very solid and robust and whilst I did not test them to destruction (I have to return them!), they do give you the feeling that you have a quality instrument in your hands that should handle even the toughest conditions.

The protection does not end with the really solid feeling shell, as they have been covered with a hard rubber armoring which will protect them from scratches as well as small bumps and knocks. Because the armor is so hard, it is not as tactile as some binoculars out there, but will still improve the grip compared to a un-rubberized binocular. This armour has another benefits in that they making the bins less reflective and will dampen down any sounds, if say your watch or ring strikes against the barrel - an important feature if you want to remain unnoticed when observing timid birds and other wildlife.

Fog and Waterproof
These Kowa binoculars are waterproof, which apart from moisture also protects them from small debris and dust found in dry environments. They have also had all the air in them replaced with dry nitrogen gas that prevents the internal optics from fogging when you get rapid temperature changes. This moisture free environment also helps to protect the inner workings from corrosion.

The Eye Cups
The eyepiece housing looks to be made from a hard plastic or something similar, as do the twist-up eyecups, which have then been covered in a fairly thick and soft rubber coating. They are pretty comfortable even when pushed quite firmly against your face. The ocular lens has a diameter of 19mm, whilst the eyecup has an external diameter of 39mm.

I really love the twist-up (helicoid) mechanism on these SV binoculars - it is very smooth and has an very good 4 fixed stops (2 intermediate), meaning that eyeglass wearers have large amount of flexibility when adjusting the eye-relief to suit their exact needs. The maximum of 15.5mm of eye-relief is pretty good and should be enough for most people who wear glasses to be able use these optics without having to remove their glasses and still get the full field of view without any vignetting. Non-eyeglass wearers will just use the eyecups in the fully extended position.

Focusing
The central focussing wheel, like the eye-cups looks like it is made from a hard plastic, covered in a soft rubber coating with large indents cut out of it for styling and to help with grip. It has a diameter of 32mm which is large enough so as to make using them even with thick gloves on, no problem at all.

The focusing mechanism is geared so that it takes about 1 and a quarter turns of the wheel to go from infinity to it's minimum focusing distance of 4m (13.1 feet). What this means is that focusing from near to far (or vise versa) is not as quick as a binocular that takes less amount of turning (some take as little as half a turn), but they do have the advantage of making fine tuning your focus to get it exactly right a little easier.

Diopter Adjustment
Located on the right barrel, between the eyecup and the barrel is the diopter adjustment ring. The mechanism is not notched/ratcheted and is not as tight as many and so could quite easily be moved accidentally. Although there is a marking on the barrel and quite a few on the diopter ring and so if you remember your mark, it would be simple to return it to your desired setting. For those who don't know, the diopter setting is used to correctly set up and focus the binoculars to your particular eyesight and only needs to be done once.

Best Binoculars Rating for Body Construction Quality: 7/10

The Optics

The Prisms and their coatings
It is good to see that Kowa have used BaK-4 glass on the roof prisms as opposed to the inferior BK-7 prisms found on cheaper optics, this superior optical glass helps to produce clearer images.

On top of this there are also phase correction coatings on the prism glass. They are used because when light waves are reflected at the opposite faces of a roof prism, "phase shift" occurs which means that you get a small amount of deterioration in sharpness. These coatings counter this by keeping the light in the correct color phases and therefore produce images that have better contrast, a higher resolution and improved color reproduction. These coatings are only usually found on higher end roof prism binoculars.

As well as this, Kowa highlight the fact that they use a "High Reflective Prism Coating" on the prisms, but don't state exactly what they are or what their reflectivity is. The best of these are dielectric coatings that cause the prism surfaces to act as a dielectric mirror and has the effect of increasing the reflectivity to more than 99% across the visible light spectrum meaning that you get better light transmission (brighter images) and excellent color fidelity. But considering their very competitive price point, I suspect though that it might be one of the cheaper high reflectivity coatings like an aluminum mirror coating that has a reflectivity of between 87% to 93%, or possibly a silver mirror coating that increases reflectivity to about 95% to 98%. Either way all a far better than binoculars that don't have any at all.

Lenses
Fully multi-coated lenses are used on the SV binoculars, which means all air-to-glass surfaces have received multiple layers of anti-reflective coatings which increases light transmission to produce a brighter image and therefore better low light performance.

These and high reflective coatings on the prisms can make a really big difference on the brightness of the image produced. I have often seen binoculars with smaller objective lenses, but high quality anti-reflection coatings easily outperforming binoculars with much larger objective lenses, but with fewer or no coatings. Beware of these lower quality optics that will often only add multiple anti-reflection coatings to the outer surfaces of the lenses (Multi-Coated) and cheaper still are optics that only have a single layers of anti-reflection coating added to the outer lenses (Coated). The very cheapest optics have no anti-reflective coatings at all and I highly recommend staying well clear of these.

The table below shows Transmittance by type of lens coating:

Best Binoculars Rating for Optical Components Quality: 8/10

Optical Stats

Field Of View

The field of view for these Kowa 10x42 SV binoculars is 105m at 100m / 315ft at 1000 yards (6°) - which, for a binocular with a 10x magnification is well above average, but does fall a little short of the very best. For example something like the Minox 10x42 BV's have a field of view of 342ft at 1000 yards (6.5°).

Close Focusing Distance
The minimum distance that you can focus on an object is 4m (13.1ft) away. This must be said is a long way off some of the best and I consider anything under 6ft to be very good. So would not recommend these to anyone who wants to use them for observing objects at close range - butterflies for example.

Eye-Relief:
Their maximum eye-relief of 15.5mm is very good and even though they just miss out on making it on my list of long eye-relief binoculars, it should be more than enough for most people who wear glasses.

Best Binoculars Rating for Optical Stats: 6/10

Image Quality

As I do for all my reviews, I compared the view through these Kowa SV 10x42 binoculars with that of my control 10x42 binoculars:

Contrast & Colour Reproduction
The contrast produced was to my eyes really good and once you have correctly focussed on an object the image is pin sharp. I also thought that the depth of field was also pretty good. The colors that are produced look and feel nice and natural, unlike the artificial tints that you sometimes find on cheaper binoculars.

Image Brightness
Testing was carried out on clear and bright morning and in terms of image brightness, I could notice as small improvement between these and my benchmark binoculars and so because of this I rate them well above average in this department.

More about Image Brightness & Low Light Performance
Good light gathering ability is important because quite often you will find yourself in situations where the lighting is sub-optimal, especially in thickly wooded or forested areas, early in the morning just before or at sunrise or late afternoon when most birds and other animals are at their most active. All 10x42 binoculars, including these SV's have an Exit Pupil of 4.2 and a Twilight Factor of 20.5, both of which indicate that they will perform pretty well in most low light conditions.

But no matter how much light your binoculars gather, it is no good if that light is not passed onto your eyes (transmittance) and so it is important to remember that not all 10x42 binoculars are created equal and the image brightness and the performance of a pair of optics in poor light also depends hugely on the quality of the glass and optical coatings and not just the exit pupil and twilight factor formula. Good coatings on the lenses and the prisms can in some cases double the amount of light that gets through the binocular, when compared to those that have none or poor quality coatings.

But as I have already mentioned these Kowa use good quality coatings and glass that contribute to them transmitting more light to your eyes and therefore produce a brighter image than inferior binoculars of the same configuration.

Color Fringing
This is always a hard one for me to judge, but to check for any color fringing (chromatic aberration), I focus on light coloured and white objects sitting in front of a dark backgrounds as this is where it is easiest to notice if there is any color fringing on the edges of the light coloured object. Whilst at times you can make some out, I found it really difficult to detect, which is really impressive.

Softening
The amount of softening of the image right at the edge of the view is very minimal and is only noticeable if you are really looking for it. This is very impressive and I would say that in this area, these better than most in this class and as good as many far more expensive than these.

Overall and to sum up, I would rate the view through these 10x42 Kowa's as excellent.

Best Binoculars Rating for Image Quality: 8/10

10x42 Kowa SV Comparisons

Below is a table comparing this Kowa SV 10x42 with a selection of other full size roof prism binoculars with magnifications 10x. The Minox 10x42 BV's, the Swarovski 10x42 EL's, the Steiner 10x42 SkyHawk and the Zeiss 10x42 Victory FL Binoculars.

Comparing a mid priced binocular like these Kowa SV binoculars with some that are far more expensive may seem a little unfair at first, but as long as you keep in mind the price difference, it does throw up a few interesting points and can highlight a few of their relative strengths and weaknesses.

What the table above does highlight is the fact that they are very light weight and have a pretty good field of view for a full size 10x porro prism binocular, but compared to the very best 10x42 binoculars, their minimum focusing distance falls quite a bit short.

Included Extras & Attention to Detail:

Neck Strap
The next strap that comes with the Kowa SV series binoculars is nice and wide and very well padded. It looks to be well made and is of fairly good quality, but is not quite as deluxe as what you get with the Kowa Genesis 10.5x44 XD Binoculars for example. I like the attention to detail in that the padded section that hangs around your neck is curved to ensure that it hangs more naturally.

Carry Case
The soft carry case is nice and roomy and there is plenty of room to carry the optics with the eyecups fully extended and with the Interpupillary Distance set to maximum. It does not come with it's own strap, so to carry it on your shoulder, you feed the binocular's neck strap out the sides of the lid when they are in the case. On the back of the case there is a loop which you can thread your belt through to carry it on your waist. The flip up lid is held close with a strip of Velcro. There are no extra pockets on the outside or inside which can be useful for carrying things like lens cleaning cloths, some money, keys or other small personal items.

Lens Covers
The eye-piece (rain guard) cover is made from a very flexible plastic/rubber and fits nicely, if a little loosely onto the eye-pieces and could accidentally fall off, but not that easily - if that makes any sense? I like the fact that it has a flexible bridge between the two cups that allow for the different distances between the two eyepieces depending on your inter-pupillary adjustment. This is something that is often overlooked by manufacturers meaning that the eyepiece covers wont fit, unless you store your binoculars fully open, which can be a real pain as you have to adjust them every time you use and replace your binoculars.

The objective lens covers are made from plastic and fit very well into to the ends of the barrels of the binocular and should not easily fall off. Each of them has a loop which can be used to attach them them to the neck strap.

Rather surprisingly these Kowa binoculars did not come with a lens cleaning cloth, but does have a fairly comprehensive generic SV series instruction booklet that includes details on adjusting the eyecups, how to properly attach the neck strap, the inter-pupillary adjustment, how to properly focus your binoculars, lens care and cleaning, and all SV binocular specifications.

Kowa Guarantee
Kowa provides a limited lifetime warranty for this binocular.

Tripod Adaptable
There is a small cover or cap on the front of the central pivoting point that screws off. This allows you to then screw on a binocular tripod adapter (not included) that uses the standard ¼-inch threading, which you can then attach to your tripod.

Best Binoculars Rating for Extras & Attention to Detail: 6/10

Conclusion

Strong Points: The standout features of these Kowa 10x42 SV binoculars for me is just how lightweight they are and the bright and high quality image that they produce, thanks to the high quality glass elements and coatings that are used in their construction.

Weak points? The only real weakness of these is their minimum focussing distance of only 4m (13.1ft), which if you don't spend a lot of times observing objects from close range is not that big a deal.

Ideal Uses: Like most 10x42 binoculars, these SV's are ideal wildlife observation optics, and whilst their field of view is narrower than the 8x42 version, they still make pretty good birding binoculars, especially if most of your birding is done in wide open areas or over longer distances like at a lake or by the sea. Hunting is another ideal use for them and I would say that they are light and adaptable enough so as to be considered great general use optics.

This would more than hold it's own as a binocular to take camping, on safari or to, I would suggest the ideal binocular for these purposes would be a little more compact.

Whilst this Kowa SV may not reach the lofty heights of the excellent Kowa Genesis 10.5x44 XD Binoculars, I think that for their price you get a very good quality binocular and Kowa have done a great job in filling the gap of potential customers who want a quality Kowa, but can't justify or who can't afford to spend the amount needed for their flag ship models.

Acknowledgments

I would like to thank Alpha Digital Services Ltd, the UK distributors of Kowa for sending this binocular to me to review, but would also like to point out that all the reviews on this site, including this one are my opinion and are not influenced in any way by manufacturers, distributors or suppliers.