Kowa Genesis/XD 8x33 and 10x33 (2 Viewers)

brocknroller said:

Agreed. The gap is closing, at least optically. Chinese bins could still do a bit more in terms of build quality and QC.

I hope Zen Ray/Promaster/Hawke makes an 8x32 open bridged ED model.

I'm interested to find out if the new Kowa 8x33 ED has the same lack of pincushion as the full sized bins. That was a "non-starter" for me after reading Holger's review.

The fullsized LX and LX L have the same issue, no pincushion so the images roll very noticeably while panning, though it appears that most users are able to adapt, and the rolling ball "disappears" for them eventually.

The mid-sized LX models have some pincushion so the "rolling ball" is much less and I find it tolerable (the also have some field curvature).

Perhaps the mid-sized Kowa ED series will also have some pincushion?

If anyone has tried one, please include comments about the smoothness of the image while panning. Thanks.

Brock

Click to expand...

I've not tried one but I noted in Holger's most recent paper on Rolling Globe effect (which you may be alluding to) where he uses Kowa as an example of a bin that uses very low amount of pincushion (so shows a lot of rolling globe effect).

It's usually the case that this is a optical design choice i.e. that the exponent that controls the amount of pincushion is essentially part of the "Kowa Design Experience".

So I wouldn't expect this to change in other similar models across the range e.g. it was true of earlier 8x33 Kowa bins too (according to Holger).

But someone has to check.

Kevin Purcell said:

I've not tried one but I noted in Holger's most recent paper on Rolling Globe effect (which you may be alluding to) where he uses Kowa as an example of a bin that uses very low amount of pincushion (so shows a lot of rolling globe effect).

It's usually the case that this is a optical design choice i.e. that the exponent that controls the amount of pincushion is essentially part of the "Kowa Design Experience".

So I wouldn't expect this to change in other similar models across the range e.g. it was true of earlier 8x33 Kowa bins too (according to Holger).

But someone has to check.

Click to expand...

Kevin,

Thanks for that info. It Kowa's previous 8x33 bins had almost no pincushion, it's a safe bet that the new 8x33 ED doesn't either.

Curiously, this is not the case with the full-sized vs. mid-sized LX/LX L.

Why would Kowa want users to see the image through their binoculars roll over a curved surface as part of the "Kowa Design Experience?"

I could even see the rolling ball effect with the full sized LXs while stargazing! The Greeks were right, the sky is made up of "Celestial Spheres".

Am I incorrect in assuming that most people want to see as natural a view as possible while looking through binoculars for daytime use?

If that weren't the case, then why even put erecting prisms in binoculars? If we use them without erecting prisms long enough, we'll adjust to an upside down and reversed image world like chickens do.

http://www.zbirding.info/zbirders/blogs/sing/default.aspx

I don't adapt as well to perceptual distortions as chickens, which is why I like my 8x32 SE.

It's not quite as bright as my 8x30 EII, and the colors aren't as "snappy" as my 8x32 LX, but it has the most natural view of all my binoculars.

Panning is smooth, without the rolling over the ball of the LX or the rolling under the ball of the EII (pincushion), and the off axis sharpness goes almost to the edge.

Nikon accomplished this while adding the right amount of pincushion distortion to make panning smooth. So why doesn't Kowa in its Genesis bins or Nikon in its LX/LX L and EDG roofs?

I've never heard the reason why a lack of pincushion is a good thing in birding binoculars.

Perhaps, the designers are chickens? Who better to design birding binoculars than another bird?

Brock

brocknroller said:

I've never heard the reason why a lack of pincushion is a good thing in birding binoculars.Brock

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Well, I can readily imagine someone seeing his horizon bend up and down, or his trees and lampposts bend in and out, think all this should be avoided in binoculars. Remember there are lots of people also who demand a binocular's sharpness to be equallly good in the center as on the edge. There are even people who claim their binocular is performing this trick!

Another thing is, that while I use or have used such differently designed binoculars as Leica's, Nikon SE's, Kowa XD and KOMZ BPO 7x30 I happen to be completely immune to rolling balls or whatever. I mean, I can't see it. And believe me, I have tried very, very hard.

Renze

There are plenty of possible reasons:

1. If you are in an manmade environment the pincushion to correct for the rolling ball can be obnoxious when looking at a stationary target with vertical and horizontal lines. Not an issue in a natural area.

The bins I have which show the effect most are my Swift Eaglet 7x36 which (so I've been old) are widely used by police forces for observation.

2. The other consideration is the bins weren't design for panning but for looking at a target. Then moving and looking at another target.

Zeiss initially were reluctant to make the move to add pincushion because they don't like to distort the view. That might be a consideration for astronomical use (who are willing to put up with it for the more accurate preservation of angles in the view).

3. Because the optical designer likes it that way?

4. Because Kowa has always done it that way. It's part of their design style.

Regardless it's a given for a particular bin ... and if it doesn't work for you ... then no matter how good the bins are you willbe annoyed with it.

That said, like using progressive lenses in eyeglasses that introduce GOBS of distortion that your brain proceeds to "tune out" in 10 to 14 days, your brain can adapt to a certain amount of it. I found the Eaglets very annoying when I first started using them. Now, not so much.

I'm like Renze, I seem to be immune to rolling ball effect. I too have tried really hard to see it, just hopefully to better understand what people are talking about. So, unlike Kevin and his Eaglet, Steve does not see it in his.

So I guess it is like the old question of "if a tree falls in the forest and no one is there to hear it, does it make any noise?" I guess the corollary is just because I don't see the effect does not not mean it is not there. I guess my take on the subject that unless they show up, I simply do not care much if they are there, and I do not take pains to make sure I keep looking until I find them.

There some other defects (characteristics?) that show up that I can see (if I stop myself and seriously go looking for them), but that do not bother me. The more into my optics hobby I get, the more grateful I become of this.

I'm with Steve on this (and apparently the others in this thread) were we can see (once again) that bins are rather personal objects and how a bin works for one person is not always a great guide for how it works for another.

Usually we can agree in "objective" qualities of a bin but some of the bins properties might just be unacceptable for a given person.

Hi guys,
Yesterday I had an opportunity to try 8x33 Genesis. I wanted to try 8.5XD but the dealer didn't have them in stock ('special order only' - I've been told). So I tried its smaller sister instead.
Yes, there is quite prominent globe effect. I looked on buildings' walls and when panning, I could easily see this rolling ball effect. When looking on straight vertical line there was very tiny pincushion visible.
As for CA, this bino is really great - almost none! Off centre I could see a little bit, but very thin and not very intense colour. I also had a quick look through Leica 8x42 HD and the CA was much worse, plus very strong pincushion distortion.
Its 8 deg FOV didn't seem that wide, rather comparable to Leica's 7.4 deg, more or less. It could be an illusion though, as I didn't check it accurately. But subjectively, it wasn't wider than my Nikon's 8x32 SE.

On the downside, off-axis sharpness was poor. I simply couldn't obtain good sharpness when the object was placed off-centre, especially to the right or left periphery of FOV. Re-focusing didn't help much. I checked this property on Leica's and it was very good, I mean there was off-centre blur made by curvature , but I could refocus to acceptable sharpness.
Build quality wise - top class, nice rubber covering, very smooth focusing (as opposed to Leica's juddery focus), with one exception - the eyecups. They were loose when fully up, made rather cheap impression.

Overall, very nice little bino, with top notch CA suppression.

Regards,

Maciek

Hello Maciek,

Excellent review, I can easily relate to all aspects mentioned.
Comment:
I think what you call off axis-sharpness could be called sweet spot. So there's a limited sweet spot. I'm pretty certain, on theoretical grounds and from direct experience, that the 8.5XD is much better in this respect.
Also, I expect the rather narrow sweet spot to be related to the subjective impression of the FoV.

Renze

brocknroller said:

The fullsized LX and LX L have the same issue, no pincushion so the images roll very noticeably while panning, though it appears that most users are able to adapt, and the rolling ball "disappears" for them eventually.

The mid-sized LX models have some pincushion so the "rolling ball" is much less and I find it tolerable (the also have some field curvature).

Perhaps the mid-sized Kowa ED series will also have some pincushion?

Click to expand...

Perhaps a slightly more general comment but Holger also points out that Fujinon 8x30 FMTR-SX (with field flattener) has no correction either (and it has a field flattener so it's sharp to the edge). The Nikon is the SE.

http://holgermerlitz.de/nikon8x32.html

Holger Merlitz said:

Rectilinear distortion: The Fujinon is almost free of distortion. Consequently, the still image preserves horizontal or vertical lines almost to the outer parts of the field, whereas the moving image displays the characteristic 'rolling ball' effect, i.e. the image seems to roll over a semi-sphere when scrolling. The Nikon employs a slight pincushion distortion to compensate for this effect, and the scrolling of its image is very smooth and without any apparent residual motion.

Click to expand...

So there are others out there and of course even a single company is not consistent in design.

Renze de Vries said:

Hello Maciek,

Excellent review, I can easily relate to all aspects mentioned.
Comment:
I think what you call off axis-sharpness could be called sweet spot. So there's a limited sweet spot. I'm pretty certain, on theoretical grounds and from direct experience, that the 8.5XD is much better in this respect.
Also, I expect the rather narrow sweet spot to be related to the subjective impression of the FoV.

Renze

Click to expand...

Thanks, Renze.
Yes, I meant 'sweet spot', it was fairly small on the specimen I tried.

I learnt from many excellent posts on this forum, that this kind of off-centre blur is caused by astigmatism and I find it distracting, almost eye-straining. My eyes adapt quite easily to field curvature but not to astigmatism it seems.
I'd really like to try 8.5 Prominar, I phoned today another two local optics dealers that I know stock Kowa binoculars and got the same answer: 'special order only' :-C
I will have to wait until August and BirdFair at Rutland Water to try one.
So far my litle nikon SE serves me well :t:

Regards,

Maciek

KOWA showed the world that it is possible to produce a high-end binocular for an affordable price. I can't wait to have my copy in my hand. I will never ever buy a binocular over $2.000 again

Szimi