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Kowa Genesis 8x33 vs Nikon EII 8x30 mini review. (1 Viewer)

Pinewood

New York correspondent
United States
Hello Black Crow,

Stereopsis means a stereo effect or an appearance of three dimensions. Porro binoculars, but not reverse Porro binoculars, give an enhanced three dimensional view.

Happy bird watching,
Arthur :hi:
 

black crow

Well-known member
It is no big deal. Help her find and set her IPD on the E2. The E2 has an IPD scale on it to make it easy.

After that fold the eye cups down for her and and set the binocular to her IPD. Ideally the center hinge will be firm rather than loose.

Then have her put the binocular up against the lenses on her glasses. She still will see a very wide FOV with the 8x30 EII; much wider than any FOV she experienced using other binoculars. She might have to fine tune her IPD but that won't be difficult.:king:

Bob

This worked! Thanks
 

black crow

Well-known member
Hello Black Crow,

Stereopsis means a stereo effect or an appearance of three dimensions. Porro binoculars, but not reverse Porro binoculars, give an enhanced three dimensional view.

Happy bird watching,
Arthur :hi:

Well I dig it. It's pretty cool and I notice it in these more than any other porro I've used.
 

black crow

Well-known member
OK now for the Tracks 10x42 older version. My friend was very very happy. Super impressed and so was I. Nice balanced binocular. Easy to hold and look through. Looks pretty clear to the edge and a nice sweet spot, pretty bright. I found nothing to criticize. She can hold them very steady and so thinks 10x is right for her. What a deal with $100 off.


OK I'm exhausted from looking through binos today. I really need some sleep.

This place is great and you guys are all great. I'm very glad I returned to Birdforum. I've been missing out.
 

black crow

Well-known member
Oh one last thing. Due to the fact that the "Japanese effect" was all in my head lol. I'm giving the win to the EII 8x30 as the best binocular. The fact that the Kowa is a roof prism binocular of that quality that it can compete and still be one of the lesser expensive alpha types I would encourage everyone interested in the roof alphas to give the Genesis 8x33 some serious attention. The next few days call for rain and I'll be out in it with the Genesis. Perfectly happy.
 

black crow

Well-known member
It's optically that they are somewhat better but the Genesis is no slouch. I really do like the 3d effect I get in the EII. It's really pronounced.
 

Theo98

Eurasian Goldfinch
It's optically that they are somewhat better but the Genesis is no slouch. I really do like the 3d effect I get in the EII. It's really pronounced.

Due to the wider spaced porro objectives, the extra 3D effect is a very desirable trait by many in the BF community! :t:

Ted
 

looksharp65

Well-known member
If you cover one of the objectives on each of the binoculars and assess the perceived magnification, I'm quite sure you will find no difference.

The greater parallax of porro binoculars means that the image of an object at short or medium distance will get closer to the medial parts of the FOV of each tube, compared to a roof binocular (or reverse-porro) where the object will be shown more towards the center of the FOV.
When the object appears to the left in the right tube, and to the right in the left tube, you must converge more with your eyes to not experience diplopia (double-vision).

So what goes on here?
When you converge with your eyes, your brain will recalculate the object size. It will appear smaller and closer.
It is easy to show this perceptual phenomenon with a weak prism from the trial lens kit.
With one eye closed, the prism will only move the image sidewards. No change of the apparent object size will happen, since the prism has no dioptric power.

With both eyes open and the prism base facing laterally, the eyeballs are forced to converge and the object will appear smaller. With the prism base facing nasally (and this may only be possible at shorter viewing distance), the eyeballs can converge less than without the prism, and the object will seem bigger.

So, with porro binoculars, you're forced to converge more, but only at finite distance. For astronomic viewing, there's no apparent size difference.
Reverse-porro binoculars do the opposite. Their construction with a tiny parallax means that they have a built-in convergence, which makes their magnification seem considerably more powerful when looking at nearby objects.

//L
 

black crow

Well-known member
Thank you sincerely for that very clear explanation of what I was calling humorously the "Japanese effect". That's pretty neat. I think I get it. Enough to satisfy me anyway.
 

Theo98

Eurasian Goldfinch
Thanks for the optics info, LS...very interesting! :t:

That "Japanese effect" also follows the "Austrian effect", which also follows the "... effect", etc.!

Uh Oh, starting to see the world cross-eyed now...:eek!: :-C ;)

Ted
 
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adhoc

Well-known member
Can you roll the eye cups down for glasses wearers?
Yes you can.
I don't remember reading what follows about the EII model but unless Nikon has improved the eyecup material it will have the same problem. In Nikons of some years back if the eyecups were folded down and up many times they creased and then cracked at the fold, and if a glasses wearer kept them folded down then after some time they could not be folded back up due to stiffening.
 

dries1

Member
Some viewers who wear glasses, flip them over to get their eyeglasses closer to the ocular lens, that way they can see more of the FOV. Rubber eye ups give two options only, all up or down.

Andy W.
 

black crow

Well-known member
That's a good idea. I hope I remember that. Can you have glasses made that way lol. That might be a niche product for birders.
 

bluespiderweb

Great Grey Looking Out
Some viewers who wear glasses, flip them over to get their eyeglasses closer to the ocular lens, that way they can see more of the FOV. Rubber eye ups give two options only, all up or down.

Andy W.

Thanks Andy, I had forgotten that! I keep mine folded down, and some think that less stressful than to keep folding them down and back up. And applying Armoral once in a great while, though I'm not sure I want Armoral touching my eyelids, etc.

But now I'm going to pull them off, and put them on backwards, and see if it brings me close enough to get that immersive view I want in the EII and SE-I don't wear glasses with bins.

Besides, if they are still making EII's, the eyecups should be still available as new parts in the future. So if you like them folded down (gives you a larger eyecup that you can rest on your brow if you prefer, or if you have large eye sockets). There have been posts about the eyecups and how to order them before here.
 

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