Lens fungus on a rigid I-50?

[wolves3012]

I've recently acquired a Zork 2C, which arrived a few days ago. Bought off the bay, the seller wasn't entirely honest although she appears not to sell cameras usually, so I'll forgive what could be inexperience. The "smooth focussing" turned out to not so smooth and what little lubricant there was was very dried up. Easily sorted. The "works properly on all speeds" turned out to mean that it did fire, sort of. The second curtain release was all gummed up so it only "fired" on releasing the button. Easily sorted. First curtain tension was so low that only the second curtain colliding with it caused it to open. Easily sorted. Self-timer didn't release the shutter, though it did unwind. Small spring dislodged, sorted. A thorough lubing has it all running smoothly & reliably now.

Ok, enough of the ramble...I think the lens has fungus but since I've never seen it before I don't actually know what I'm looking at. There are some very fine, almost-clear, spidery threads visible with a 10x eye-glass. They appear to be on the back of the front element and somewhere probably on the front of the second. There isn't a great deal of it, but is this fungus?

Assuming it is, what's the likelihood of being able to remove it and what's the chances there's permanent damage? I have other lenses I can use so I'm not going to cry if it's not fixable but I'd rather keep the lens available since it seems to be the original.

I think the camera has been kept in a loft or something, since there's evidence of dampness inside it. There was some furry corrosion of the alloy in places, which I've cleaned off. Presumably good conditions for fungus?

The other bit of help I could do with is how to strip the lens fully, I can't seem to find anything on the rigid I-50. I'm sure someone on here will point me to where I should have found it - I have looked, honest!

 

[Screwy]

Sounds like the start of fungus , I have similar on an early J8 , Not to sure about damage , the main concern is etching of the glass as far as I know , also It's considered a good idea to store the affected lens away from unaffected lens to avoid cross contamination though all this is just what I've picked up on the web .

the only link I have is one on Tom Tigers site for a partial strip down of the rigid I-50 , Hopefully it is of some use .



Paul

 

[wolves3012]

Update: After a bit of paranoia and thorough checking, I've found traces of fungus in four lenses, three I-50s and an I-26M. The I-26 was easily cured since it was just beginning, around the periphery of the front face of the front element. A quick wipe round with alcohol got rid.

The three I-50s didn't fare quite as well. One is an SLR version and the rear face of the rear element had some pretty stubborn stuff right in the middle. 95% has gone but it's left a couple of tiny spots that won't come off. I don't want to risk abrading it.

The other two I-50s had fungus on the rear of the very front element. Removing these was easier than I feared. On both of them the coating has been damaged and the threads have left a pattern of missing coating. Not too bad, one of them it was very little and cannot now be seen with the lens reassembled,. The other one has left a more obvious etching but it probably won't affect pictures (I hope!).

One thing I did find - a little hard to believe but there was a VERY tiny flea, or some such insect, in between the front and rear groups in one lens! It was maybe 0.5mm long and almost clear (and very dead!). Presumably it's been in there for the last 50 years. Beat that for a find!

 

[JonP]

Wolves you think you have problems look here
http://www.certo6.com/gallery/planar.html

 

[tobias]

Hi there,
I am looking for tips on what kind of lubricant to put in shutter cams, and i find something i do know about. hah.

I thought that fungus was the end of the world (which reminds me that i should take my enlarger lenses apart), but then found, after some research and experimentation, that there are several things you can do, and one thing that works really well, to remove it. Hydrogen Peroxide kills most living cells, so if you want to kill the fungus, then use peroxide. said this, by the time you see the fungus it is probably long dead. However the fun bit is that to remove the fungus you want to soak the lens in white vinegar. none of these chemicals hurt the lens or coating, so it is fine to leave it for an hour or so. but i found that just soaking it for maybe 10 minutes allowed for the little tree patterns to just slide off with a cotton swab. then i think you want to use some ethanol or isopropanol to remove the vinegar residue.

good luck
t

 

[longw]

Hi there,
However the fun bit is that to remove the fungus you want to soak the lens in white vinegar. none of these chemicals hurt the lens or coating, so it is fine to leave it for an hour or so. but i found that just soaking it for maybe 10 minutes allowed for the little tree patterns to just slide off with a cotton swab. then i think you want to use some ethanol or isopropanol to remove the vinegar residue.

good luck
t

Hi tobias,

Could you say more in details about this tip? I have two M42 lenses which have fungi everywhere. Those fungi might have dead already. But I am looking for an easy way to remove them.

So, just soak the lens into white vinegar, that easy? But is it harmful to the mechanical part, the moving part? And, after that, the fungi will disappear?

Thanks,
tao

 

[Nickfed]

The other bit of help I could do with is how to strip the lens fully, I can't seem to find anything on the rigid I-50. I'm sure someone on here will point me to where I should have found it - I have looked, honest!

This might get the ball rolling if you haven't started already

http://www.rangefinderforum.com/forums/showthread.php?t=10633

 

[wolves3012]

Thanks guys, I decided to have a go and found the I-50 pretty easy to disassemble. They're all done now (3 I-50s and they all had fungus!). Seems the fungus has eaten at the coatings to some degree but they aren't too bad and I think it's not really going to affect images.

 

[wolves3012]

So, just soak the lens into white vinegar, that easy? But is it harmful to the mechanical part, the moving part? And, after that, the fungi will disappear?

Vinegar will corrode aluminium if you leave it too long, but it will take a while to do noticeable damage.

 

[wolves3012]

Hi there,
I am looking for tips on what kind of lubricant to put in shutter cams, and i find something i do know about. hah.

I thought that fungus was the end of the world (which reminds me that i should take my enlarger lenses apart), but then found, after some research and experimentation, that there are several things you can do, and one thing that works really well, to remove it. Hydrogen Peroxide kills most living cells, so if you want to kill the fungus, then use peroxide. said this, by the time you see the fungus it is probably long dead. However the fun bit is that to remove the fungus you want to soak the lens in white vinegar. none of these chemicals hurt the lens or coating, so it is fine to leave it for an hour or so. but i found that just soaking it for maybe 10 minutes allowed for the little tree patterns to just slide off with a cotton swab. then i think you want to use some ethanol or isopropanol to remove the vinegar residue.

good luck
t

Thanks very much for the vinegar trick, it certainly works! I thought the coating was damaged on my two I-50s but I decided to have another go at the worst one first. 10 minutes or so in white vinegar and I was looking at a pristine lens (well, not counting the cleaning marks on the front anyway). The second one fared just as well, as did a J-8 that came on my '62 Zorki 4.

Never ceases to amaze me at the simple tricks we hold as collective knowledge on here, with such a willingness to share and help each other out....

 

[tobias]

Indeed. All we need is an editor to now gradually compile the useful tips together into a useable database. God would that be useful.

I am very glad that the vinegar has worked for you too. The thing with it is that vinegar is probably the last think you might think of using to clean a lens, and yet it appears to be all that you need.. so glad i could help.

t

 

[longw]

I would have a try with white vinagar. Maybe wash the lens with fresh water after soaking? It sounds lik washing an apple. 🙂