has530
Well-known member
I had the opportunity today to try Kowa's budget and middle class compacts side by side in the field and figured I may was well write down my observations here for anyone trying to decide between the two (or who may be otherwise interested). In general I like both very much for their price and they share a surprising amount of similarities with some obvious differences I found quite interesting.
Build Quality: +BD
This is the major area in which the price difference makes itself known. The SV's feel solidly built with a solid feeling housing and high-quality rubber armor but there are some obvious cost cutting aspects. The eyecups are too short and made of cheap feeling plastic. The focuser is made of similar plastic and on my specimen has significant backlash/play when changing focus direction. In contrast the eyecups on the BD feel much nice and click firmly into place and are comfortable to use (likely to do with their larger radius as well due to the BD's larger eye lenses). The Focuser of the BD is also nice textured rubber and a joy to use. It has absolutely no play, is just the right speed, and larger making it much easier to use. It is worth noting that my specimens of the BD and SV and made in Japan and China respectively.
Compactness: +SV
One of the main reasons someone may get a compact binocular instead of at least 30mm of aperture is for their portability/small size/dimensions. In this regard the SV takes the cake. The double hinge design folds down much smaller into a handy belt look pouch. The BD has a single hinge design which while more robust and easier to use does limit their fold down size. The BD is also about 1/4" longer and 1 oz heavier.
FOV: dead even
The BD is spec'd 0.1 deg wider but focusing both to infinity and putting one up to each eye and facing a white wall I saw absolutely no difference.
Central Sharpness: dead even
This one surprised me but in a handful of controlled resolution tests both hand held and mounted and in the field I could see no difference at all in central sharpness (or edge sharpness except maybe the BD being a hair ahead right at the field stop but this may have to do with the ease of eye placement with its larger eyecups).
Contrast and brightness: +BD
This is the one striking area in which the BD excels. It has dark darks, bright brights, saturated colors, and a brighter image. It is not the brightest I have seen in this class (Kowa claims silvered prisms which may contribute) but it easily outguns the SV. The SV view is greenish while the BD is pinkish and looking down the barrels shows nicer AR coatings on the BD with much lower intensity reflections.
Glare: +BD
The aforementioned higher quality coatings probably help it best it's cheaper counterpart here but the interior tubes also look more matte. Neither control glare well at all but the BD definitely wins (the smaller dimensions of the SV also probably hurt it in this category).
Chromatic Aberration: dead even
Surprisingly going back and forth between the two I could see no difference which is a nice feat for the SV with it's smaller length. It is well controlled in both cases with slight CA in the center and low on the edges.
In conclusion, these two models share very similar optical qualities with the obvious difference in most cases being the attention to detail and build quality in the higher-priced japan-made BD. This gives advantages such as a brighter image with less glare and smoother focusing. Given that Kowa has claimed the SV was developed in tandem with the higher priced models and the optical similarities, I would not be surprised if they shared some optical components with the SV's lower price coming from the added costs of the mechanical details and Japanese labor costs. In the end I am keeping the SV as a through-hiking compact as if I would be willing to carry the single hinge BD I would be willing to carry something larger so they do not suit my needs for a "pocket" binocular.
Build Quality: +BD
This is the major area in which the price difference makes itself known. The SV's feel solidly built with a solid feeling housing and high-quality rubber armor but there are some obvious cost cutting aspects. The eyecups are too short and made of cheap feeling plastic. The focuser is made of similar plastic and on my specimen has significant backlash/play when changing focus direction. In contrast the eyecups on the BD feel much nice and click firmly into place and are comfortable to use (likely to do with their larger radius as well due to the BD's larger eye lenses). The Focuser of the BD is also nice textured rubber and a joy to use. It has absolutely no play, is just the right speed, and larger making it much easier to use. It is worth noting that my specimens of the BD and SV and made in Japan and China respectively.
Compactness: +SV
One of the main reasons someone may get a compact binocular instead of at least 30mm of aperture is for their portability/small size/dimensions. In this regard the SV takes the cake. The double hinge design folds down much smaller into a handy belt look pouch. The BD has a single hinge design which while more robust and easier to use does limit their fold down size. The BD is also about 1/4" longer and 1 oz heavier.
FOV: dead even
The BD is spec'd 0.1 deg wider but focusing both to infinity and putting one up to each eye and facing a white wall I saw absolutely no difference.
Central Sharpness: dead even
This one surprised me but in a handful of controlled resolution tests both hand held and mounted and in the field I could see no difference at all in central sharpness (or edge sharpness except maybe the BD being a hair ahead right at the field stop but this may have to do with the ease of eye placement with its larger eyecups).
Contrast and brightness: +BD
This is the one striking area in which the BD excels. It has dark darks, bright brights, saturated colors, and a brighter image. It is not the brightest I have seen in this class (Kowa claims silvered prisms which may contribute) but it easily outguns the SV. The SV view is greenish while the BD is pinkish and looking down the barrels shows nicer AR coatings on the BD with much lower intensity reflections.
Glare: +BD
The aforementioned higher quality coatings probably help it best it's cheaper counterpart here but the interior tubes also look more matte. Neither control glare well at all but the BD definitely wins (the smaller dimensions of the SV also probably hurt it in this category).
Chromatic Aberration: dead even
Surprisingly going back and forth between the two I could see no difference which is a nice feat for the SV with it's smaller length. It is well controlled in both cases with slight CA in the center and low on the edges.
In conclusion, these two models share very similar optical qualities with the obvious difference in most cases being the attention to detail and build quality in the higher-priced japan-made BD. This gives advantages such as a brighter image with less glare and smoother focusing. Given that Kowa has claimed the SV was developed in tandem with the higher priced models and the optical similarities, I would not be surprised if they shared some optical components with the SV's lower price coming from the added costs of the mechanical details and Japanese labor costs. In the end I am keeping the SV as a through-hiking compact as if I would be willing to carry the single hinge BD I would be willing to carry something larger so they do not suit my needs for a "pocket" binocular.
