EBC Fujinon 50mm f1.4 Fungus cleaning.

Kathmandu · Expire: 2012-04-08

I bought this lens a few months back and was hoping to clean it as it was infested with fungus.

After scouring the web-I found nothing on opening this lens to access the necessary elements. I put the lens in a UV box for 2 weeks and then out in the summer sun for a few days-to no avail. Iwas able to open the filter ring by unscrewing the three screws on the side and that was the extent of it. I could see no way of unscrewing the front cell or the back cell. I used the lens with the fungus , and I was getting beautiful images with it even with the infestation. I put the lens away in a ziplock bag , and away from other lenses, in hopes of one day opening and cleaning.

Well that day has come and I managed to open to open it up through the front and dissassemble the front cell and clean it.

Heres what I did:

Took the name ring off by unscrewing the front ring, which was held down by three tiny screws.

I could see the front cell with 2 holes on the side. This is threaded and glued down. I applied a couple of swaps of acetone and painted in between the cracks with a pointed Q-tip soaked in acetone. I firmly placed the tips of my spanner tool(the pointed tips-mine has a sloted one and a ponted one )into the two holes amd turned the spanner tool anti-clockwise firmly pushing down at the same time- and est voila it turned .I was never able to do that previously.

I unscrewed the front cell and could now see that the fungus was behind the front element, and on the face of the element underneath the iris. I blew the dust off the opened parts and used a lens brush on the open parts gently cleaning loose particles off-and then using the blower again.
I opened the iris wide open and applied an antifungal cream on the element under the iris without disassembling that portion further. I dont even know if the back cell can be disassembled. I left it with the cream on for 20 minutes or so and later cleaned it off with a q-tip soaked in denatured alchohol, and a clean lint free lens cleaning cloth. I used vapor from my breath on the element and wiped it clean.

The front element was held down by a threaded and glued retaing ring. I applied acetone in the previously mentioned method, and used a knife blade tip to scratch ,break apart and clean some of the glue in the cracks. I used a rubber band to aid in gripping the lower part of the front cell and a latex gloved hand to twist the retaining ring (anti-clockwise) . I tried a few times , making sure I wasn't touching any part of the element, and managed to unscrew the retaining ring.
I used the same method in cleaning the fungus from the back of the front element.When the fungus was cleaned off ,I cleaned the threads of the retaining ring with de-natured alchohol ,and applied some naptha on the threads-before putting the newly cleaned lens elements back on the front cell.

I then applied some naptha on the front cell threads and used the blower one last time inside the lens to blow away any dust particles.

The lens was then put back and reassembled.

lens mounted on a sony alpha adapter .

I hope someone finds this useful-as I could on find anything on the wild wild web.

Regards

Excalibur · Expire: 2014-04-21

Excellent report even though I don't have a Fuji 50mm f1.4.

tomasg · Expire: 2014-04-28

Excellent, makes me want to buy lenses that i don t need, just to fix them... Rolling Eyes

Tomas

indianadinos · Expire: 2011-12-05

Great, thanks for sharing the tutorial ...

Kathmandu · Expire: 2012-04-08

polarhei · Joined: 29 Dec 2011 Posts: 29 Location: Hong Kong,PRC

Your guide is very noticeable,although I have not the material needed, after a little cleaning internally, Improved a little.
The remain may need some liquid to do.

Although Some people seldom know what we are exactly doing(thinking I am destroying a len). Fixed focus length lens like fujinon 50mm may be the most simple to fix (as there are not more than 3 pieces of glass). Now I have some problem to fix my standard 80-200 M42 Tokina Lens.

P.S: I used to face similar thing before, a Model of Double-len camera,35mm format so Fixed focus len (Fujinon?) in M42 should be easy to maintain.

my_photography · Expire: 2016-12-25

Some of the photos are no longer available. I am tring to 'jam' the auto pin on the lens but having difficulty to start since I don't see any screw at the rear of the lens. There are 1 screw on the aperture ring and 3 on the distance ring. Any suggestion?

Jesito · Expire: 2015-01-07

Thanks for the report! Nice to see the inside of that lens.

(BTW I notice some of the pictures not being properly loaded with the page, I suggest better to store them at MFLenses directly, just to avoid third party picture repositories losing them.)

Arkku · Joined: 28 Feb 2007 Posts: 1416 Location: Helsinki, Finland

The Fujinon 50mm f/1.4 is one of the easiest lenses to modify for manual aperture: simply open three screws near rear of the lens (above aperture ring) and the whole rear part comes off. Take out aperture pin (open two screws holding it, but leave one still slightly attached so easier to reassemble), cut a ~1.5mm piece of hollow plastic tube from, e.g., “q-tip” aka cotton swab, insert over aperture pin, and reassemble. When reassembling, there is one “fork” on the mount side which needs to go grab a pin on the lens side (controls aperture).

Also, re. cleaning, unless there is fungus between the front elements, easiest way is to screw off entire rear element group, this gets you easy access to all elements below the aperture blades and the one surface above aperture blades without having to undo name ring (which is hard without scratching the ring).

my_photography · Expire: 2016-12-25

I am in trouble now, this black ring came off and I have no idea where exactly I should put it. The aperture no longer move when I changed the aperture ring.

I think the white fork tab - "A" should be put in "C".

but it does not really fit, this is how it looks when I reassembly it back. The black tab is now on top of the silver ring

By the way, did I put back "D" correctly to jam the pin?

Arkku · Joined: 28 Feb 2007 Posts: 1416 Location: Helsinki, Finland

my_photography · Expire: 2016-12-25

I managed to put the black ring in, but the small white pin (picture below - cycled area) does not move with the ring. What should be moving that area and is it possible to show me how it looks like at f16 and @1.4? Sorry I am new at this lens fixing thing and obviously I am no good at it.

@f16

Arkku · Joined: 28 Feb 2007 Posts: 1416 Location: Helsinki, Finland

my_photography · Expire: 2016-12-25

After mounting the lens back, the aperture will only response from f1.4 to f4 after that no change in aperture even if I change the aperture ring. What did I still do wrong? Any suggestion?

my_photography · Expire: 2016-12-25

spiridon · Joined: 14 Apr 2014 Posts: 3

Hi All!
Does anyone have an idea of how to open old-style EBC Fujinon 50/1.4 ? It doesn't contain these tiny screws..

My lens also has yellow tint and this leads to pictures warming. So can someone who faced this problem share with the experience of UV treatment or smth like this ?

Arkku · Joined: 28 Feb 2007 Posts: 1416 Location: Helsinki, Finland

UV treatment in sunlight, or with certain white LED lights works for the yellowing.

I have opened mine, I don't remember there being anything strange about the process; there are three rings on the barrel of the lens just above the knurled aperture ring.

spiridon · Joined: 14 Apr 2014 Posts: 3

Thanks for the answers, UV really works. But after measuring the radiation decided not to bother