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Fungus? (1 Viewer)

comaderek

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In a few posts it states you need to worry about fungus for binoculars.

Can you explain why it is such a problem and how to guard against fungus appearing?

Is it because binoculars are normally cased?
 
In a few posts it states you need to worry about fungus for binoculars.

Can you explain why it is such a problem and how to guard against fungus appearing?

Is it because binoculars are normally cased?

All fungi will absorb and diffuse light diminishing your image brightness. Some will etch the glass, so even IF it is removed, the outline of where it was will remain. A thorough cleaning requires the instrument to be disassembled, cleaned, reassembled, and collimated—$$. If that doesn’t bother you ... no problem. Also, the problem starts with its environment, not its case. Guarding? Keep in a dry environment. :cat:

Bill
 
There are fungal spores in the air.
In a humid environment they thrive.
I think from memory that they feed on protein from fingerprints, dust mite material, skin particles etc.
They use the minerals in the glass as a nutrient?

Some old glasses are almost immune to fungal attack. 150 year old lenses may be quite clean except for a natural surface blooming.

In binoculars, purging the air with nitrogen or argon, I think, guards against the problem, but only so far.

Typically it appears as spider patterns on the glass.
Either the glass or coatings are susceptible.

Australian optics in WW2 were rendered useless in 6 weeks from new.
So they had to learn how to clean them in the field.
Vast amounts of silica gel, I think, was used to store them.

I had a mothballed Williamson F52 camera completely encased in desiccant bags. This is a big camera with the 36inch Dallmeyer f/6.3 telephoto lens.

Tropics are the most demanding environment.

Some lenses, such as old Olympus zooms especially, often are useless from fungus.

So, a waterproof binocular is the way to go.

In the U.K, the temperature should be above 13C and humidity less than 50%.

Storing any optics in a typical garage in the U.K. is the same as throwing it in the garbage.
Storing in an attic is not much better.

Yes, being in a case can be worse.

I got a brand new Chinese waterproof binocular that already had fungus inside. So much for their makers environment.

This is a large topic.

P.S.
Fungus is rather easily cleaned off an external surface if seen early enough.
However, the fungus can track around the edge of the lens element into the interior of the optics.
 
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Mold is also something I see inside optics.
The type I see is usually black.
I am not a biologist, but there are many types of mold and related mildew.
There is mention that some types thrive in relative humidities of 62% to 93%.

In the tropics relative humidities above 90% I think occur in jungle areas with high temperatures. Here fungal attack can be rapid.
With military optics, they are abused a lot and suffer accordingly.
Other problems with aerial lenses are that filters are left off causing more problems. I also have seen dozens of RTH 4 inch f/1.8 lenses that have sandblasted almost opaque front elements.

I use a portable air conditioner, which reduces relative humidity.

Mold also affects humans.

It was reported that a contribution to Brittany Murphy's and later her husband's passing was mold, although I don't know the outcome of the claims.
Unfortunately many British homes have big problems with damp causing health problems.
 
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