What to do about small fungus...

[john_gerndt1]

I have a nice 1911 Voigtlander Heliar No. 7, 16-1/2" with one small

spot of fungus inbetween the rear (I assume) element pair. I am not

worried about it affecting the optics (much) but I would not want it

to spread and ruin the lens. Is there an outfit that specializes in

cleaning up lenses of this vintage? It is in aluminium barrel and I

cannot by hand disassemble it. It may prove welded with corrosion

though there is no outward indicator of this.

 

I am seeking recommendations from you experienced men (or women).

 

John D Gerndt

 

OH, if anyone knows, what may be the coverage of this lens. I have

only had it mounted to a 8x10.

[øyvinddahle]

1. Know for sure what it is!

2. If it's fungus, kill it with UV rays (energysaving UV bulb, I'm treating a lens right now)

3. Keep it dry! Use plastic bags with fresh silica gel.

 

Consider to send it off to a pro, like S. Grimes.

 

If you live in a humid area, consider purchase an automatic dryer cabinet to protect your lenses.

 

http://www.chem.helsinki.fi/~toomas/photo/fungus/

 

Øyvind:D<div></div>

[c_p_goerz]

Use some Methyl Ethyl Ketone on it, will clean up in a jiffy. Don't breathe in the fumes as they can be carcinogenic.

 

CP Goerz

[john_gerndt1]

Thanks guys for your responces. I will try some strap wrenches to get the thing apart. I don't guess it is worth the $ to fix/repolish the glass if it turns out to be etched. I just wanted to stop the fungus growth.

 

John D Gerndt

[ole_tjugen]

Judging from my experience with a 1934 Heliar 150mm, yours should have an image circle of at least 500mm - 40". Sufficient for most formats...