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Trying to unfungus a nice Canon FD 50mm 1.8
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PostPosted: Tue Aug 30, 2011 8:31 pm    Post subject: Trying to unfungus a nice Canon FD 50mm 1.8 Reply with quote

Martinsmith99 has been so kind of providing me with one for free (thanks Martin!) and I committed to a tutorial on disassemby and fungus killing.

This first attempt has been unsuccessful (in removing the fungus) but anyway, I'll show the lens and the steps taken.

This is the lens. Martin told me about some incipient fungus around the top lens border:



You can see them quite clearly:



On the bottom lens there were also some suspicious spots:




So I started from the top. At first I thought the 50mm 1.8 had a screwed nameplate, so I took the rubber lens wrench for that diameter and tried to unscrew it:





But the plate was turning without unscrewing, so I went to the laptop and searched for "FD 50mm disassmbly" and found the page from Rick Oleson where he disassembles the 50mm 1.4. I learned there that the plate was glued and not screwed, so I protected the lens with s piece of microfiber fabric and placed a small plastic screwdriver under the plate. It popped up and showed the top of the lens itself:



Three small screws that fix the top. Taking them out , frees the retainer for the top optical element:





Gently turning down the lens dropped the top element.



It seems to be made up of two lenses, glued onto a plastic piece:





Not clear to me if the fungus was on top or inside the lens, so I used the common practice: hands cream on top of the lens:




For half an hour I was expecting the same results than with the 500mm mirror (that one had a worse infection).

But unexpectedly the treatment didn't provide any results. So I have to infer these fungus are not on top. It will be really difficult to disassemble the top element, so I assembled it back for now and see what else can be done.

Again thanks to Martin for such nice opportunity to learn about lenses..

Regards.
Jes.


PostPosted: Sat Sep 03, 2011 7:29 pm    Post subject: Reply with quote

Thanks for sharing. I am in the search for a 50 canon lens, and (as I always do) will look for a fungused or a not-working-iris one, for price sake. It seems a very easy lens to work with. Regards

Javier


PostPosted: Sat Sep 03, 2011 9:53 pm    Post subject: Reply with quote

wupdigoj wrote:
Thanks for sharing. I am in the search for a 50 canon lens, and (as I always do) will look for a fungused or a not-working-iris one, for price sake. It seems a very easy lens to work with. Regards

Javier


Thanks for your comment, Javier.
Yet, it's quite easy, but beware where the fungus are: if they get inside the lenses, they are almost impossible to clean without expensive equipment.
The iris seems easy to handle. Once removed the top element you are in front of it, and is fixed by a few screws.

Good luck,

Jes.


PostPosted: Sat Dec 03, 2011 9:14 pm    Post subject: Reply with quote

Hi Jes,

the two lenses of the central element in 50 nFD 1.8 are not glued onto a plastic piece, they can be separated. I just did this by gently but firmly pulling the plastic piece (which allows rotation for focusing, by the way, so it couldn't be glued : ). Once you've done that, carefully pull the smaller lens, which will come out.
I'm presently cleaning my fungus this way : )

Ciao,
GT


PostPosted: Sat Jan 28, 2012 6:21 pm    Post subject: Reply with quote

GT wrote:
Hi Jes,

the two lenses of the central element in 50 nFD 1.8 are not glued onto a plastic piece, they can be separated. I just did this by gently but firmly pulling the plastic piece (which allows rotation for focusing, by the way, so it couldn't be glued : ). Once you've done that, carefully pull the smaller lens, which will come out.
I'm presently cleaning my fungus this way : )

Ciao,
GT


Many thanks for the tip!. I have to open it again, it has been put into an autoclave to kill the fungus... and also has killed the diaphragm Sad

Will report!.

Regards.
Jes.


PostPosted: Sun Jan 20, 2013 6:50 pm    Post subject: Reply with quote

Sadly S.C. version has all front system elements wrapped in one piece of plastic which cannot be separated as described above. I already started carving plastic profile to release the front element (under which fungus resides). Is there a better way to get the element out?




PostPosted: Sun Nov 22, 2015 1:44 am    Post subject: [img]http://forum.mflenses.com/userpix/201511/9403_IMG_1893_ Reply with quote

this is the "second" element from the front of a canon fd 50mm 1.8 lens. it is not a single element, it is either glued or welded together somehow. and this is where I have found fungus or iridescent snow flake-ish like patterns, which may be in the coatings. however this is not a single element as some have suggested, it is 2 elements bound together somehow. how do we get them apart?[ href=" target="_blank" rel="nofollow" class="postlink">


PostPosted: Sun Nov 22, 2015 8:25 am    Post subject: Re: [img]http://forum.mflenses.com/userpix/201511/9403_IMG_1 Reply with quote

kimherrick wrote:
this is the "second" element from the front of a canon fd 50mm 1.8 lens. it is not a single element, it is either glued or welded together somehow. and this is where I have found fungus or iridescent snow flake-ish like patterns, which may be in the coatings. however this is not a single element as some have suggested, it is 2 elements bound together somehow. how do we get them apart?[http://forum.mflenses.com/userpix/201511/9403_IMG_1893_2.jpg[/img]][/img]


PostPosted: Fri Dec 04, 2015 7:46 am    Post subject: Re: [img]http://forum.mflenses.com/userpix/201511/9403_IMG_1 Reply with quote

kimherrick wrote:
this is the "second" element from the front of a canon fd 50mm 1.8 lens. it is not a single element, it is either glued or welded together somehow. and this is where I have found fungus or iridescent snow flake-ish like patterns, which may be in the coatings. however this is not a single element as some have suggested, it is 2 elements bound together somehow. how do we get them apart?


You don't. These elements are glued together, and while taking them apart is not that complicated putting them back together will most likely be well beyond your ability.


PostPosted: Sat Oct 01, 2016 7:22 am    Post subject: Reply with quote

Gardener wrote:
kimfherrick wrote:
Plus "second" element from the front of a canon fd 50mm 1.8 lens. it is not a single element, it is either glued or welded together somehow. and this is where I have found fungus or iridescent snow flake-ish like patterns, which may be in the coatings. however this is not a single element as some have suggested, it is 2 elements bound together somehow. how do we get them apart?


You don't. These elements are glued together, and while taking them apart is not that complicated putting them back together will most likely be well beyond your ability.


I would soak it in salt water first to kill the fungus and then put vinegar on it.