Photography Fungus inside the lens

[Vas (Jack)]

Has anyone had fungus inside their expensive lens ? If you had, how did you removed it and how it be prevented to get inside the lens ?

 

[panos_adgr]

I happen to have lens with fungus. My old Helios 81N.
It is very hard to be removed. UV lamps help from what I've read. Some say that cleaning with isopropyl alcohol does the job but it sounds quite risky for the lens coating....

 

[Vas (Jack)]

I happen to have lens with fungus. My old Helios 81N.
It is very hard to be removed. UV lamps help from what I've read. Some say that cleaning with isopropyl alcohol does the job but it sounds quite risky for the lens coating....

Do you need to take the lens apart ? I don’t think I have any fungus on any of my lens. Just wanted to know for the future.

Is UV lamps removes the fungus ?

 

[panos_adgr]

Do you need to take the lens apart ? I don’t think I have any fungus on any of my lens. Just wanted to know for the future.

Is UV lamps removes the fungus ?

From what I've read UV might help.
As for dismantling the lens, it has to do with the elements affected by fungus which in most cases are the front and rear and in some cases even inside if the lens was stored in humid environment for long time or if it is uncarefully used through time in moist scenarios, without proper care after shooting.

In either case it would be wise to to send the lens to a specialist because after dismantling the lens for cleaning, calibration of elements is a must to have proper image quality across the frame plus that it must be done in a sterile environment (if possible or as much as possible) due to dust particles.

 

[Vas (Jack)]

From what I've read UV might help.
As for dismantling the lens, it has to do with the elements affected by fungus which in most cases are the front and rear and in some cases even inside if the lens was stored in humid environment for long time or if it is uncarefully used through time in moist scenarios, without proper care after shooting.

In either case it would be wise to to send the lens to a specialist because after dismantling the lens for cleaning, calibration of elements is a must to have proper image quality across the frame plus that it must be done in a sterile environment (if possible or as much as possible) due to dust particles.

Thanks for the information. Then seems I would never risk to try on any of lenses.

Might look for UV lamp at home. Is it good idea to expose lenses to UV lamp even if there are no fungus inside ?

 

[panos_adgr]

Thanks for the information. Then seems I would never risk to try on any of lenses.

Might look for UV lamp at home. Is it good idea to expose lenses to UV lamp even if there are no fungus inside ?

There is no reason to expose a lens to UV.
The only lenses that should be exposed to UV are vintage lenses with thoriated elements (radioactive lenses) because due to the radioctive decay they have a yellow / brown colour cast. I have one.
These lenses are usually treated with UV lamps to restore the elements and remove the colour cast.

Thorium was added in the 50s and 60s to lens elements to improve optical properties of the glass.

''Thorium is added to glass, up to 30% by weight, to provide improved optical properties. Specifically, glasses with an index of refraction greater than 1.65 and with the product of Abbe constant and index of refraction greater than 70 are often made with thorium.''

 

[Vas (Jack)]

There is no reason to expose a lens to UV.
The only lenses that should be exposed to UV are vintage lenses with thoriated elements (radioactive lenses) because due to the radioctive decay they have a yellow / brown colour cast. I have one.
These lenses are usually treated with UV lamps to restore the elements and remove the colour cast.

Thorium was added in the 50s and 60s to lens elements to improve optical properties of the glass.

''Thorium is added to glass, up to 30% by weight, to provide improved optical properties. Specifically, glasses with an index of refraction greater than 1.65 and with the product of Abbe constant and index of refraction greater than 70 are often made with thorium.''

Thanks a lot for this information. Really helpful. So basically the modern lenses shouldn’t have problem with fungus?

 

[panos_adgr]

Thanks a lot for this information. Really helpful. So basically the modern lenses shouldn’t have problem with fungus?

Well I do not know about synthetic elements. But Glass elements need attention. Generaly all lenses need attention.

 

[Vas (Jack)]

Well I do not know about synthetic elements. But Glass elements need attention. Generaly all lenses need attention.

Thanks panos_adgr. Well, I will check my lenses, but so far all my lenses are in good state. I won't risk cleaning them myself if I'll find some fungus inside the lens.