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Kowa BD 8x42 with XD real compared Zeiss Conquest HD and Nikon Monarch 7 (1 Viewer)

The BD and the BD XD are different with the BD being the older model. It is however made in Japan and in my opinion of much better build quality. The BD XD is the newer model and is made in China. It does have ED glass and is really pretty good optically except for the slick focus knob problem which I have mentioned above. The older BD model is pretty good also but except for the 8x32 model with 393 ft. field of view, all other models have a pretty narrow fov. Jim
 
I personally felt that the old BD was a rather disappointing binocular. To be honest I didn't spend much time with it, but I recall the colour, contrast and sharpness were not what I might have expected for the price.

The BD XD appears to be a totally different design. The XD refers to a low dispersion element (ED). I first tried it at the UK launch 18 months ago and found the CA bad. Not a little bit bad, but a lot bad, and the representatives on the stand I think were more than a little embarrassed. Apart from that, the whole colour, contrast and sharpness I thought was much improved. Last summer I checked out those BD XDs again together with and the new additions to the range. The CA was improved considerably from the previous year but definitely not class leading even then. I think it's potentially a very nice binocular if you are not particularly CA sensitive.

David
 
Personally I don't find the focus wheel to be overly slick. In the rain, maybe it would be an issue.

Is the term "CA insensitive" a construct of bird forum members? Or is their academic research to support the condition in humans? I assume anyone can see CA (assuming their visual acuity is sufficient and conditions are conducive to it).

As with most binoculars, with the Kowa BD 8x42 XD, the CA is noticeable when viewing vertical lines under high-contrast conditions when you go left/right of center (or even out-of-focus on-center). The purple with the Kowa is a brilliant purple, so it is more visible than with some binoculars. In the center, in-focus, it's not an issue.

Compared to modern alpha-class glass, the off-center CA is definitely very prominent. I can't say whether it's better or worse than competitors in the same price range though. Which binoculars in the $500 range have class-leading control of CA?

If you are observing groups of birds against the sky, then well-controlled CA might be very important to you. If you tend to observe single birds under lower contrast conditions, then it probably wouldn't be a significant factor for you.

Overall, I feel the view provided by the Kowa BD 8x42 XD is excellent (and in a relatively lightweight package).
 
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Ads, I agree that the view is excellent in the BD XD and I have no problem with CA at all. I really have to be looking for it to see it at all and only when my eyes are positioned indirectly in the eyecups.
 
Is the term "CA insensitive" a construct of bird forum members? Or is their academic research to support the condition in humans? I assume anyone can see CA (assuming their visual acuity is sufficient and conditions are conducive to it).

Well I'm pretty sure I've never seen it, so maybe I'm CA insensitive. But then, I've had three eye surgeries in the past eight years, so maybe CA isn't an important factor for me.
 
Is the term "CA insensitive" a construct of bird forum members? Or is their academic research to support the condition in humans? I assume anyone can see CA (assuming their visual acuity is sufficient and conditions are conducive to it).

Although we are normally unaware of it, chromatic aberration is part of the normal optics of the eye. It does vary significantly between individuals with the aberrations of the cornea and lens, symmetry of the cornea and pupil diameter. We don't see it because of the neural filtering in the higher visual system removes it from the concious visual experience. So the brains of some individuals need to do more correction than others. I've not been able to track down if and how this ties in with the range of sensitivity to supplementary CA from binoculars etc. but from many, many reports on the forum such differences exist.

The most striking example I've witnessed was went I was trying out various binoculars alongside two first time buyers. I tried a 12x50 which was probably faulty and had the worst CA I've ever seen. A leafless bush in the view was just awash with high intensity fringing. The sales person had just been trying to explain ED glass and CA to the novices so I handed the binocular to them to try. The first just went "Wow! What's with the neon light display" the other guy spent the next ten minutes trying to find it, and failed. It convinced me!

Hope that helps.

David
 
The first just went "Wow! What's with the neon light display" the other guy spent the next ten minutes trying to find it, and failed. It convinced me!

It could have been due to a number of other factors: eye positioning, viewing the target off-center, or even just poor eyesight by the one viewer.

Even reviews by birdforum members must be taken with a grain of salt. There is opinion wheat here, but also opinion chaff.

I think to be a good optics reviewer, one must be highly observant, meticulous, have good eyesight, have access to optics which are comparable, and strive to reduce personal biases. Few people meet all those points.
 
It could have been due to a number of other factors: eye positioning, viewing the target off-center, or even just poor eyesight by the one viewer.

I've checked out several hundred binoculars and that had the worst CA I've ever seen.

The full story was rather interesting, it turned out that the first guy also noticed differences in effective resolution, field curvature, pincushion distortion, astigmatism, contrast and colour rendition between different models as well, though he expressed it in different terms. Pretty remarkable for a novice I reckon. The other guy couldn't spot any of those differences. It seems a reasonable representation of the range of binocular users perceptive skills.

Even reviews by birdforum members must be taken with a grain of salt. There is opinion wheat here, but also opinion chaff.

I think to be a good optics reviewer, one must be highly observant, meticulous, have good eyesight, have access to optics which are comparable, and strive to reduce personal biases. Few people meet all those points.

Totally agree. That first guy probably had the makings of an excellent reviewer. What ever the other guy thought probably wasn't worth reading. Not so different from the forum.

David
 
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CA reared its ugly head today with the Kowa's. I was looking at a white rope clothes line that went diagonal and away from me against a dark background, and the CA was very noticeable.

At the symphony on Sunday, it wasn't an issue.
 
Totally agree. That first guy probably had the makings of an excellent reviewer. What ever the other guy thought probably wasn't worth reading. Not so different from the forum.

David

So which one would be the happier user?
Not necessarily the more critical one.
 
So which one would be the happier user?
Not necessarily the more critical one.

True, but at the time he was getting pretty annoyed that he couldn't see the characteristics his buddy was describing, specially reading the small print on a sign about 70m away.

David
 
I'm still liking my Kowa BD Prominar 8x42 XD.

The field of view is the same as the Sightron Blue Sky II 8x32 (7.5 degrees), but the sweet spot extends farther to the edge of the field.

Glare control is not as good as the Blue Sky, but it's still good.

I like the ergonomics.

I can notice an ever-so-slight difference in focus as I approach in-focus from far vs. near. There must be a bit of slop in the focus system that affects one barrel differently.

I would like to compare a Celestron Granite ED 8x42 against the Kowa.
 
I'm still liking my Kowa BD Prominar 8x42 XD.

The field of view is the same as the Sightron Blue Sky II 8x32 (7.5 degrees), but the sweet spot extends farther to the edge of the field.

Glare control is not as good as the Blue Sky, but it's still good.

I like the ergonomics.

I can notice an ever-so-slight difference in focus as I approach in-focus from far vs. near. There must be a bit of slop in the focus system that affects one barrel differently.

I would like to compare a Celestron Granite ED 8x42 against the Kowa.

Is there ring on the right eyepiece for individual focusing have ratchet mechanism or smoothly on your binoculars?
Celestron Granite ED 8x42 worse than Kowa.
 
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The diopter adjustment works smoothly.

The slop that I mentioned in the focusing from different directions is extremely small.
 
The diopter adjustment works smoothly.

The slop that I mentioned in the focusing from different directions is extremely small.

If binocular diopter adjustment is smooth, then the serial number starts with 1300500. When the serial number is from 130000 to 1300499, the diopter adjustment works ratchet. There are no slops in the focusing from different directions in such binoculars. The serial numbers can be small deviations.
 
Hi praise indeed, Alex. I'll have to try to see one of these.

Here's something I can't figure. I have attached a photo of the 8x42 to the left of the 10x42. Look at the difference in the eyepieces! And the 10x42 has LESS eye relief than the 8x42. I can't imagine the 10x42 would work with glasses, so why did Kowa do it? Or have they revised it?

Anybody know?

Not only that the eye lenses of 10x42 are smaller, they are more(way too much) recessed than the eye lenses of 8x42 model. Really bad design. The picture in it self is enough to show that you can forget eyeglasses use with it.
 
If binocular diopter adjustment is smooth, then the serial number starts with 1300500. When the serial number is from 130000 to 1300499, the diopter adjustment works ratchet. There are no slops in the focusing from different directions in such binoculars. The serial numbers can be small deviations.

Do you have any more details about the history of diopter changes in the model? They must have had issues that forced a redesign? The serial number of my 8x42 is 13008xx.

Regarding use with glasses, I don't wear glasses, so I don't know.
 
My quick comments on the 10x42: no blackouts without glasses, and the only bin that I can use with the eyecups not fully twisted out but no idea if the set is suitable for those wearing glasses. The bin is usable but not a keeper for a pretentious user: CA even in the sweet spot, visible astigmatism, the eyecups are huge and made of hard rubber and hence rather uncomfortable, and the two copies that I tested had a lot of grease inside the barrels.
Peter.
 
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