How To Avoid Lens Fungus?

I am about to bin a 45mm Mamiya 645 lens because of fungal growth on the
lens elements. If I use it at any aperture smaller than 5.6 the effect of
the ugly fungus becomes obvious. It seems to me that it has gone beyond
repair.

How best to avoid such a nasty occurrence with my other lenses?

I live in a damp climate (Ireland).

Silica Gel is one option I suppose. Another is exposing the lenses to bright
sunshine for hours on end.

Are there other options?

Is it worthwhile constructing an ultra-violet light cabinet in which to keep
the lenses?

Any advice would be much appreciated.

John

see http://medfmt.8k.com/mf/fungus.html hth bobm
--
************************************************** *********************
* Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 *
********************Standard Disclaimers Apply*************************

Carrigman wrote:

I am about to bin a 45mm Mamiya 645 lens because of fungal growth on the
lens elements. If I use it at any aperture smaller than 5.6 the effect of
the ugly fungus becomes obvious. It seems to me that it has gone beyond
repair.

How best to avoid such a nasty occurrence with my other lenses?

I live in a damp climate (Ireland).

Silica Gel is one option I suppose. Another is exposing the lenses to
bright sunshine for hours on end.

Are there other options?

Is it worthwhile constructing an ultra-violet light cabinet in which to
keep the lenses?

Any advice would be much appreciated.

John

How about a cabinet with a household dehumidifier inside? You can then
control the storage conditions of your equipment. Down side? Cost of the
electricity. But in a small enclosed space.....

Jon

"Carrigman" carrigman@DEATHTO SPAMMERShotmail.com wrote in message ...
I am about to bin a 45mm Mamiya 645 lens because of fungal growth on the
lens elements. If I use it at any aperture smaller than 5.6 the effect of
the ugly fungus becomes obvious. It seems to me that it has gone beyond
repair.

How best to avoid such a nasty occurrence with my other lenses?

I live in a damp climate (Ireland).

Silica Gel is one option I suppose. Another is exposing the lenses to bright
sunshine for hours on end.

Are there other options?

Is it worthwhile constructing an ultra-violet light cabinet in which to keep
the lenses?

Any advice would be much appreciated.

John

john:
out here in the tropics we buy electric dryboxes which come in
30litre, 60, 120, 200 and up to 500litre capacity boxes. They have a
built-in electric drying unit which controls the humidity between
40-70% (your choice)... lenses thrive at about 55%. They're not
expensive... about US$100 for the smallest... and enough for lenses. I
don't know if you can get them in ireland.

There are also "room drying" units which you can use to keep a room
fairly dry... but these units require you to clear the water-tray once
a day or so.

fungus... any competent tech. should be able to clean it... and if
the fungus is not too bad, get it done... because fungus GROWS. If its
been on too long, it will also scar the coating.

Contrary to what is commonly believed in drier climates... while
fungus is a problem, adequate cleaning is enough ... it isn't like a
virus which recurs easily and infects everything in-sight once it is
properly cleaned.

"Carrigman" carrigman@DEATHTO SPAMMERShotmail.com wrote in message ...
I am about to bin a 45mm Mamiya 645 lens because of fungal growth on the
lens elements. If I use it at any aperture smaller than 5.6 the effect of
the ugly fungus becomes obvious. It seems to me that it has gone beyond
repair.

How best to avoid such a nasty occurrence with my other lenses?

I live in a damp climate (Ireland).

Where did you store the lens? In the attic? In your garage? I would
have thought that if you kept it in the cupboard in a bedroom or
living room then you would not have a problem. Unless it is also damp
in there, of couse.

Silica Gel is one option I suppose. Another is exposing the lenses to bright
sunshine for hours on end.

Make sure the silica gel is not already saturated (I don't know how to
"refresh" it) and keep the lens in a sealed bag with silica gel
inside.

Are there other options?

Is it worthwhile constructing an ultra-violet light cabinet in which to keep
the lenses?

Any advice would be much appreciated.

John

Bob Monaghan wrote:

see http://medfmt.8k.com/mf/fungus.html hth bobm

This one is pretty interesting:

quote
rec.photo.misc
From: "Kirk R. Darling"
[1] Suggestions to avoid mildew growth on lenses
Date: Mon Feb 16 15:24:49 CST 1998

A ventilated cabinet with an incandescent light has been used for
decades by photographers in the tropics, and I can testify myself that
it worked for me in the Philippines. Simple, low tech, zero
maintainance, as long as one can afford to keep a 60-watt lamp burning
8-10 hours a day.
/quote

So the problem isn't absolute humidity (g/m3) but relative humidity (%
of saturation). The easiest way to reduce %RH is to warm the air. The
amount of absorbed humidity vs. temperature is almost exponential. A 60W
lamp is pretty effective in warming a cabinet and lowering %RH.

Another thing to avoid is thermal cycling. It will pump air and humidity
in and out, and in the process may introduce inside the lens all that
dirt that the fungus needs.

-- Lassi

In article ,
(RolandRB) wrote:

Make sure the silica gel is not already saturated (I don't know how to
"refresh" it) and keep the lens in a sealed bag with silica gel
inside.

Just put in a warm oven for a few hours

Peter

yes, but the costs of constant heating add up, and add to air conditioning
loads and so on too. Zip loc baggies with lens/camera and silica gel
packets are also more portable ;-) The silica gel is a few dollars a pound
when you buy cat litter drying crystals (which are silica gel with a blue
cobalt indicator, these crystals are larger, easier to handle, less dust).
A coffee filter plus rubber band and you are in business. The
under-the-bed clear plastic storage cases are also handy, often tight
sealing, and you can put a few silica gel packets in there to keep them
dry too. I'd use both techniques if I was someplace very humid all the
time, but for non-tropical areas the silica gel seems to be enough, and if
the indicator shows it is exhausted, all you need to do is put it in an
oven at 200 degrees F. for a few hours and reuse. So long term running
costs are very low...

hth bobm
--
************************************************** *********************
* Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 *
********************Standard Disclaimers Apply*************************

You can buy silicon dessicant (sp) at wholesale quantities and prices on
this website.

http://www.desiccare.com/unitpak.htm

"Carrigman" carrigman@DEATHTO SPAMMERShotmail.com wrote in message
...
I am about to bin a 45mm Mamiya 645 lens because of fungal growth on the
lens elements. If I use it at any aperture smaller than 5.6 the effect of
the ugly fungus becomes obvious. It seems to me that it has gone beyond
repair.

How best to avoid such a nasty occurrence with my other lenses?

I live in a damp climate (Ireland).

Silica Gel is one option I suppose. Another is exposing the lenses to
bright
sunshine for hours on end.

Are there other options?

Is it worthwhile constructing an ultra-violet light cabinet in which to
keep
the lenses?

Any advice would be much appreciated.

John

You can buy silicon dessicant (sp) at wholesale quantities and prices on
this website.

http://www.desiccare.com/unitpak.htm

"Carrigman" carrigman@DEATHTO SPAMMERShotmail.com wrote in message
...
I am about to bin a 45mm Mamiya 645 lens because of fungal growth on the
lens elements. If I use it at any aperture smaller than 5.6 the effect of
the ugly fungus becomes obvious. It seems to me that it has gone beyond
repair.

How best to avoid such a nasty occurrence with my other lenses?

I live in a damp climate (Ireland).

Silica Gel is one option I suppose. Another is exposing the lenses to
bright
sunshine for hours on end.

Are there other options?

Is it worthwhile constructing an ultra-violet light cabinet in which to
keep
the lenses?

Any advice would be much appreciated.

John