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Material Composition of NL x42 vs EL SV x42 (1 Viewer)

John A Roberts

Well-known member
Australia
Swarovski has recently posted a series of downloadable magazines from 2021 at: SWAROVSKI OPTIK

The Outdoor & Birding one includes a table showing the composition of the NL x42 in terms of materials.
This allows ready comparison to the data for the EL SV x42, shown in post #45 at: Binocular Weight, a Triviality?
For convenience, see below from left to right: the NL x42 data; the EL SV x42 data; and the data directly compared.

Swarovski lists the three NL x42’s as between 840 and 850 g (29.6 and 30.0 oz); and the two EL SV x42’s at 835 and 840 g (29.5 and 29.6 oz);
. . . so more than close enough for direct cross comparisons of the percentages.


A) Optics
As we know, the two have the same basic optical construction e.g. see a comparison image by Henry from post #42 at: Glass types in NL Pure-series

However, the NL has a much larger FOV - a 40% increase in terms of the total viewing area! See post #46 at: Baffles and Light Transmission
So the optical triumph of the NL is that such a significant increase in FOV is achieved, without any loss of optical quality.

Unsurprisingly the NL needs considerably more glass to accomplish the above, with a 17% increase in glass mass (1 ÷ 36% x 42%)
e.g. as seen in Henry’s image, the first two lenses of the eyepiece assembly are clearly considerably larger in diameter, and therefore physical volume.
However, some of the increased mass may also be due to the use of denser glass.


B) Glass vs Overall Mass
As both the NL and EL have the same overall mass, the NL necessarily has less non-glass mass at 58% vs 64%.
So the additional point can be made that the NL’s optical advantage is also achieved without any increase in overall mass or size.

In part, the lack of increased mass can explained by the tapered objective housings, which require less metal and less RA covering.


Metals
Of the two main metals used, in their pure forms magnesium is 33% lighter by volume than aluminium (though in practice various alloys of each are used).
So one would think that where practicable, magnesium would have been the preferred choice.

However, the NL both uses slightly more aluminium (at 23% vs 21%), and substantially less magnesium (at 16% vs 22%)!
Presumedly this is due to engineering considerations e.g. see the various advantages of magnesium - including the environmentally related ones -
in a screen shot from: Comparison with other metals - Magnesio & Metal

Considering Swarovski’s commitment to the use of environmentally friendly materials and practices, if it was practical to have used more magnesium,
then presumedly they would have done so.


Plastics
The NL uses considerably less plastic/ synthetic material, with a 1/3 decrease in plastic mass (11% vs 17%).

With the EL, plastics seem to have been used not only for external parts such as the RA, the eyecups and the focuser knob, but also for internal ones.
See an image of a disassembled EL x42, showing what appears to be variety of non-metallic internal components.

In contrast, perhaps for a mix of engineering and environmental considerations, it would seem that the NL has far fewer plastic internal components.


John
 

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