Swarovski Habicht ‑ Question about Waterproofing (1 Viewer)

Dialyt · May 7, 2016

How is it possible to fill these binoculars with nitrogen and guarantee waterproofing with external focusing?

My guess is that the main body of the binocular is indeed sealed, but the eyepieces are only water resistant and prone to water ingress.

Any more informed opinions?

henry link · May 7, 2016

You can see how the eyepieces are sealed in this cutaway.

Dialyt · May 7, 2016

henry link said:
You can see the relevant eyepiece seals in this cutaway.

I'm not sure what I'm looking for here. I can't see any seals, but I do see the eyepiece tubes which must slide up and down. It is this that I believe is unable to be hermetically sealed. If the little black rings are O-rings, then these would rub as they move up and down, eventually perishing. At most, it would be water resistant but not guaranteed waterproof. It would be impossible to seal the binoculars and fill them with N gas under pressure when the area occupied by the gas increases and decreases as the binocular is focused.

In any case, I don't understand how you can hermetically seal a binocular and fill it nitrogen gas that has moving parts which must inhale and expel air as they move in and out.

Gijs van Ginkel · May 7, 2016

Dialyt, post 3,
Yes it can be done and proof of it is the test I did with a WW-2 military porro binocular with B&L body and IF focussing. I left it for 24 hours under a layer of 50 cm of water (the instrument was more than 40 years old) and not a molecule of water could be detected inside the binocular. It than went for 6 months to the tropics , was used a lot and came back as if the optics was polished half an hour ago.
Gijs van Ginkel

elkcub · May 7, 2016

Dialyt said:
I'm not sure what I'm looking for here. I can't see any seals, but I do see the eyepiece tubes which must slide up and down. It is this that I believe is unable to be hermetically sealed. If the little black rings are O-rings, then these would rub as they move up and down, eventually perishing. At most, it would be water resistant but not guaranteed waterproof. It would be impossible to seal the binoculars and fill them with N gas under pressure when the area occupied by the gas increases and decreases as the binocular is focused.

In any case, I don't understand how you can hermetically seal a binocular and fill it nitrogen gas that has moving parts which must inhale and expel air as they move in and out.

I agree that an instrument designed to exchange internal/external gas during its operation probably can't be waterproof in every sense. However, if it were not operated while (being) under water it might meet static waterproof test criteria, depending on what they are. It's not an absolute thing, really.

Ed

Binastro · May 7, 2016

Even fully waterproof binoculars are limited to 5m maybe 10m depth for Steiner.

I have an old Minolta waterproof centre focus Porro. Maybe I'll stick it in the bath and see what happens.

Russian Porros are pretty good even though supposedly not waterproof. They use a goo to seal gaps.

jring · May 8, 2016

Hi,

first of all, roof bins with N2 inside are usually not under pressure either. And an external focusing mechanism is not a problem to get waterproof as shown by a lot of fully waterproof military bins with external IF focusing - like the east german Zeiss EDF 7x40 which actually was put under pressure (50kPa or 5m immersion equivalent for an hour) temporarily during the test cycle.

The challenge Swarovski was facing for the CF Habichts was to get the external center focus mechanism watertight - the rather stiff focuser of the Habichts still tells the tale - but since it is speced at 4m immersion and Swarovski tends to stick to their warranty and more, I would not worry...

Joachim

Swarovski Habicht ‑ Question about Waterproofing (1 Viewer)

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