camera lens vs. binoculars: Binoculars and rifle scopes have a gas in them that prevents them from fogging up. Camera lenses apparently don't have it and must not need it. Is this true...

olcoach Loc: Oregon

Binoculars and rifle scopes have a gas in them that prevents them from fogging up. Camera lenses apparently don't have it and must not need it. Is this true or don't the binocs and scopes have gas anymore either. I am asking as I have a lens that has some mold on the lens and I am going to see if I can take the lens apart and clean it. It is an inexpensive lens.

BHC Loc: Strawberry Valley, JF, USA

olcoach wrote:

Binoculars and rifle scopes have a gas in them that prevents them from fogging up. Camera lenses apparently don't have it and must not need it. Is this true or don't the binocs and scopes have gas anymore either. I am asking as I have a lens that has some mold on the lens and I am going to see if I can take the lens apart and clean it. It is an inexpensive lens.

The better binoculars are filled with nitrogen or argon gas to prevent fogging. I would guess that camera lenses are not because the focusing system would create expansion and contraction. Binoculars can have the focusing mechanisms independent and separate chambers dilled with gas. Some lenses, called duplex lenses because of multi-chamber construction might be amenable to the use of gas, but the space between the chambers would have to be tightly built or perhaps evacuated.

jerryc41 Loc: Catskill Mts of NY

Mogul wrote:

The better binoculars are filled with nitrogen or argon gas to prevent fogging. I would guess that camera lenses are not because the focusing system would create expansion and contraction. Binoculars can have the focusing mechanisms independent and separate chambers dilled with gas. Some lenses, called duplex lenses because of multi-chamber construction might be amenable to the use of gas, but the space between the chambers would have to be tightly built or perhaps evacuated.

Isn't one advantage of nitrogen that it doesn't expand like air? That was a big promotional point for filling your tires with nitrogen a while back.

Lenses aren't airtight, so the nitrogen wouldn't last long - zoom lenses, anyway.

DaveMM Loc: Port Elizabeth, South Africa

jerryc41 wrote:

Isn't one advantage of nitrogen that it doesn't expand like air? That was a big promotional point for filling your tires with nitrogen a while back.

One of many myths about nitrogen.

http://powertank.com/truth.or.hype/

jerryc41 Loc: Catskill Mts of NY

DaveMM wrote:

One of many myths about nitrogen.

http://powertank.com/truth.or.hype/

That's probably why I no longer see it advertised at tire stores.

stan0301 Loc: Colorado

The air is already 80% nitrogen--but the other 20% is mostly oxygen which over time will react with most anything--I doubt you would own a tire long enough to make any difference--as the "outsides of the tire will be exposed to oxygen all the time it would matter very little
Stan

olcoach Loc: Oregon

Thanks all for your answers. I can experiment with cleaning my lens without fear of something getting out I couldn't put back in. I have never had a lens fog up and we have some cold here. I wonder why? Thanks again.