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Optical Construction of HG/ LX and EDG Binoculars (1 Viewer)

John A Roberts

Well-known member
Australia
For ease of future reference, I’ve posted in this new thread information with additions,
that I posted yesterday (in a Leica thread!) about the the Nikon HG/ LX and EDG series:


It’s commonly thought that the premium Nikon roof prism binoculars have unique optical designs

This is because:
- the cross-section views seem to show the use of fewer but thicker elements than in other premium designs, and
- Nikon does not state the number of lenses in their binoculars

However, cut away images (showing the external shapes of the lenses) show more detail
and that somewhat disappointingly the binoculars are very conventional designs

In order:
A) HG - showing only groups
B) HG - lenses and groups
C) HGL - lenses and groups (i.e. the light weight version of the HG, with the same optical construction, though using lead and arsenic free 'Eco' glass)
D) EDG - showing only groups

n.b. A), B) and C) are all specifically the 8x42 versions (as indicated in the images)


As can be seen the HG/ HGL construction is:
Objective 4 lenses in 3 groups (2, 1 + 1 focusing); Eyepiece 6 lenses in 4 groups (1, 2, 2, 1)

And the EDG construction is:
Objective 4 lenses in 3 groups (1, 2 + 1 focusing); Eyepiece 6 lenses in 4 groups (1, 2, 2, 1)

So notably there is a reordering of the objective construction
The EDG focusing lens is of significantly larger diameter than that of the HG (and the EDG body has been modified to enable this)
And most likely other details of the lenses (thickness, curvature, composition and spacing) differ between the two lines


John
 

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  • HG 8x42 - cross section.jpg
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  • HG 8x42 - showing lenses.jpg
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  • HGL 8x42 - with lenses.jpg
    HGL 8x42 - with lenses.jpg
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  • EDG - cross section.jpg
    EDG - cross section.jpg
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Last edited:

Tobias Mennle

Well-known member
Thanks, John, for pointing that out - that the Nikon drawings are a lie, plain and simple.

And I was marveling at the EDG x-rays...
 

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