Binocular Weight, a Triviality? (2 Viewers)

[Tringa45]

Just to wrap up, perhaps an apology is in order if some of my posts have appeared aggressive or demeaning, but the original post was motivated by a personal situation that I was reluctant to disclose.
Many have kicked the bucket before they reach my age, so I have no complaints and sympathy would be unwanted and embarrassing.
However, as a 76 year-old cancer patient on fatigue-inducing anti-growth hormone therapy (the opposite of doping) I don't experience a 1200 g binocular as a burden after a couple of hours in the field and find it hard to understand the discussions on weight.
Many leisure activities involve volantarily induced pain but birding can bring so much pleasure for so little discomfort.

John

 

[tenex]

John: I'm very glad to know that you continue to enjoy birding without finding even your favorite binocular a burden.

My father carried a 1200g glass everywhere (Zeiss 7x50). I could do the same with my SLC 56s now... I just don't. Yet?

 

[Troubador]

Just to wrap up, perhaps an apology is in order if some of my posts have appeared aggressive or demeaning, but the original post was motivated by a personal situation that I was reluctant to disclose.
Many have kicked the bucket before they reach my age, so I have no complaints and sympathy would be unwanted and embarrassing.
However, as a 76 year-old cancer patient on fatigue-inducing anti-growth hormone therapy (the opposite of doping) I don't experience a 1200 g binocular as a burden after a couple of hours in the field and find it hard to understand the discussions on weight.
Many leisure activities involve volantarily induced pain but birding can bring so much pleasure for so little discomfort.

John

And long may you continue to enjoy your binos no matter what their weight.

Lee

 

[adhoc]

John/Tringa45, and John A. Roberts, thank you for that information, direct from you and linked, some of it fascinating. As for the question what makes today's top-tier binoculars heavier than those you describe, I see there two of the factors: more lenses, and armoring. Had forgotten that armoring can add so much weight.

 

[John A Roberts]

Hi adhoc,

In relation to current products, I suspect that it’s the glass far more so than the RA.

Going back to the image of the three Zeiss 8x56 models in my previous post, the weights are:
• Classic Dialyt 1030 g/ 36.3 oz
• Design Selection 1459 g/ 51.5 oz (42% more than the Dialyt)
• Victory (pre-FL) 1160 g/ 40.9 oz (13% more than the Dialyt)

Looking at the image it’s clear that there’s far more glass in the later two models, but it’s hard to appreciate just how much there is
e.g. the later two clearly have more glass along the optical axis, but in addition the prisms are also wider, and the DS’s eyepiece lenses are also wider.

Since the image is of 3 dimensional objects, small changes can make a big difference
e.g. as I recently posted, a small change in the diameter of a circle can have a big effect on its two dimensional area, see: NL Pure 8x32 and NL Pure 10x32!
And here we’re dealing with cubic volume.

In addition, glass density can vary a great deal. The DS was touted for it’s use of exotic glass, which among other things means more dense, and so more heavy, than usual.
In contrast, the Victory used more sophisticated lens shapes to lessen the glass mass in both the objectives and eyepieces. And with the objectives, it also managed to achieve the same magnification in a shorter physical length (compare the distances from the front objective lens face to the front prism face).


And coming forward to a quick mash-up of the classic Leitz Trinovid 7x42B and the current Swarovski NL x42, the weights are:
• TV 7x42 660 g/ 23.2 oz
• NL 8x42 840 g/ 29.5 oz (27% more)

Considering all of the extra glass in the NL, what’s surprising is that it’s only only 27% heavier. Part of the explanation may be in the use of magnesium for the body shell, but part may also be in the use of synthetic material for internal components
e.g. in relation to the two images of Swarovski products that I recently posted, I presume that 'synthetic material' is not only referring to the RA
- see all of the spacing rings in the image of a disassembled EL x42.


John

 

[adhoc]

John, thank you for all that, how thorough, as usual.

Now (addressing others also), in my post before my last I asked what made the newer top-tier binoculars that much heavier, and as examples of the points I sought I listed (in regard to glass, i.e. in addition to other factors): "lenses for closer focus, wider views, flatter views, easier viewing?" I added, to make it easier for whoever replied: "If any of those [reasons], then, although expanding will be appreciated, even a simple Yes for that will do!"

So then, were lenses added for those reasons? Have others been added to refine the image? What does the denser (in mass) "exotic" glass achieve? Thanks.

 

[Binastro]

Exotic glass reduces CA or allows a more compact instrument.

However, there are major disadvantages.
Really exotic glass degrades as soon as it is made and must be immediately hard coated.
Even cemented surfaces need to be coated in multi element designs.

In top end lenses some of the glass costs more than gold.
The lenses cost more than $20,000.
Also there are not many glass makers who can consistently meet the specs.
Some Chinese glass just does not meet requirements.

Exotic glass doesn't last very long unless the maker takes great care.

I have 1800s lenses made of simple glass that are free of fungus or degradation.

The Cooke photovisual telescopes from the late 1800s that performed so much better than previous telescopes were found to degrade after about seven to ten years and had to be repolished periodically.
The glass becomes opaque over time.

Some older Leica lenses were famous for failing glass.

It is mainly improved coating techniques that allow the use of exotic glass.

Regards,
B.

 

[Boogieshrew]

Reading this thread I can't help but fixate on the old backpackers saying that an ounce at the beginning of a days walking (change to birding) feels like a pound at the end of a days walking (birding).
Weight matters to me. I have stopped using/sold lots of binoculars because they are more than I can carry all day.

 

[John A Roberts]

I just came across an image of a disassembled Zeiss Design Selection 8x56 on the Dutch site De Kijkerspecialist ('The Binocular Specialist'), at:
Projects - De Kijkerspecialist (I’ve slightly adjusted the exposure to show more detail)

It helps to highlight that unsurprisingly the internal design and construction of binoculars has evolved over time, reflecting the development of different production techniques and economies.


In terms of a chronological progression, see:
a) Zeiss 8x30 Jenoptem Porro prism; the post-WWII version of the Deltrintem that was introduced in 1920 *
b) Zeiss 8x56 Design Selection roof prism introduced in 1994
c) Swarovski EL SV x42 introduced in 2010, and
d) Maven B2 x45, also a current design *

As can be seen, in several ways the DS’s detail is similar to that of the much earlier Jenoptem design. In contrast, both the EL SV and the B2 make use of far more parts, including many standardised rings and washers.
And notwithstanding the Maven branded B2 (from the Japanese OEM company Kamakura?) has a significantly simpler focuser mechanism than the EL SV, it makes use of even more parts - especially what seem to be off-the-shelf ones.


* The sources are:
• The Jenoptm is from Ant1 at Cloudy Nights: Service Manual for Zeiss Jenoptem 10x50(w)? - Binoculars - Cloudy Nights
(unfortunately, the image is no longer attached to the post)
• The Maven B2 is from Todd McLellan at Popular Mechanics: We Tore a Pair of Binoculars Into 172 Parts


John