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Nikon eii 8x30 internal design/dimensions? (1 Viewer)

Dancat

Well-known member
Hi all,
I'm currently doing a school project where I need to accurately model an object using a CAD program. I decided to model my eii binoculars, as their design interests me. The challenge is that I do not want to open up my bins just to get the internal dimensions and layout for this one project. I was wondering if anyone had access to a manual of sorts that might have this information, or has opened up a pair of eii's in the past and has photos or dimensions of the internal design. Any help is appreciated. Thanks in advance!
 
Hello Dancat,

I’ve not seen any cutaway or exploded views of Nikon’s EII porro’s. However an Allbinos article includes an actual x-ray of the EII’s construction: https://www.allbinos.com/168.1-article-Legendary_binoculars_-_Nikon_8x30_EII.html

You can clearly see the optical construction: the objective doublet; the prisms (and that the objective prism - the one physical closest to the eyepiece - is larger than the ocular one), and; the ocular construction (5 lenses in 3 groups of 2 elements, 2 elements and 1 element). Contrary to what’s stated in the text, there does not appear to be a sixth element in the eyepiece.

Henry Link has previously written about the optical construction of the Nikon SE, EII and E series: https://www.birdforum.net/showthread.php?t=38202 . Usefully he calculated the following for the EII 8x30 (the information is in the fourth and fifth paragraphs of the initial post):
Objective focal length c110 mm
Eyepiece focal length c13.75 mm
Field stop diameter c17 to 17.2 mm
This may be of assistance in calculating internal dimensions.

Porro prism binoculars have similar/time-proven internal designs and mechanics. If you google ‘binoculars cutaway’ and then go to the Images option at the top of the page, you’ll get to see a lot of binocular internals, including some porro models. Even better would be to buy a cheap old porro binocular and take it apart to study the details.
 
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Dencat,
I've attached a cutaway of a Swarovski porro prism. It gives a clear view of some of the of the internal construction details, common to many porros.
 

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...the ocular construction (5 lenses in 3 groups of 2 elements, 2 elements and 1 element). Contrary to what’s stated in the text, there does not appear to be a sixth element in the eyepiece.

Hi John,

I thought the same thing when I first saw that x-ray, however Arek was kind enough to provide an eyepiece x-ray with better detail. In it you can see the narrow air space separating the field lens from the first of the two cemented doublets.

Henry
 

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