50 1.4 ML disassembly...?

Many thanks for the link. I think I may have to surrender and send it to a professional for cleaning; even using the correct JIS screwdrivers, I'm in danger of shredding the retaining screws on the mount... 

P.S. images taken with ml 55 f4

First hello to all !

Please, any help is welcome:

I want to clean up fungus on front element on my Yashica ML 50mm f/2.0.


First i set min focus(0.5m), i tryed unscrew(on the left) front barrel with hand, but no way. Then i put lens into NEX adapter, i put around barrel 1cm rubber, then i tryed unscrew with hands but without lucky  , barrel wont budge..


Any idea ?

Thanks biggles3 for quick respond.


If I understand correctly, i must first unscrew back screws, then disassemble all parts on back, in fact, on this Yashica lens front panel is last (he was the last to whom i come) ?  Similarly for
DSB 50mm f1.9 www.flickr.com/photos/7699588@N07/sets/72157632482008350/ ?

Laufer,

Welcome to the forum.  Sorry to see you are having problems with the disassembly of your ML 1.4/50.  Like Biggles says, it may be of a different construction than the DSB 1.9/50.  Never having owned one, or needed to take one apart, I can't tell you.

If there is fungus directly behind the front element, then you are basically out of luck as far as removing it. This is because the front element is part of a cemented group, and you would have to separate the elements to clean off the fungus. It's not a task us amateur repair folks were meant to take on. It was a little easier to do back when Canadian Balsam was used as the cement, but now it's some sort of UV actuated glue that would take more than the usual hot water heating to get it to loosen its grip.

Then after getting everything looking good (that is, if the fungus didn't etch the lens), you have to be able to put it back together in precise alignment, or suffer from really weird looking images forever. This takes proper tooling which the manufacturers won't make available to anyone except the most professional repair establishments. If the lens is etched, then you are looking at having to regrind it, something else left to the professionals. There are not many places left that do this kind of work, and they are expensive to say the least. If ground, then the element would also need to be re-coated.

Now if the fungus happens to be on the rear of the front element group, then it can possibly be cleaned. Sometimes you can do this by removing the rear group, and opening up the aperture to access the rear of the front group. You then run the risk of not being able to get the rear element cleaned correctly, which will leave a haze behind, and affect the lens sharpness.

Some methods of removing the fungus involve Ponds Cold Cream, a 50/50 solution of hydrogen peroxide and ammonia, athletes foot cream, or the oil from your nose (which happens to be highly anti-biotic).

My take on the whole matter is, get another lens from a dry climate. I have a feeling that the Yashica ML lenses are susceptible to fungus invasion more than any other modern lens around. But here are some other thoughts on the matter.

To cure a fungus invasion of a camera lens, nothing works better than good old sunlight, or a strong UV lamp. Fungus thrives in the dark, so take your lenses out to shoot often enough to kill any spores that may be trying to settle in. And keep the UV filters off unless they are necessary (like shooting in the mountains around here for instance). You can also kill an established invasion by putting the lens in sunlight (don't let the exit beam burn a hole in whatever is behind the lens), or the aforementioned UV lamp, for a period of a couple of days to a week. Though this may leave behind the remains of the fungus, it will lessen its affect on image quality. And speaking of such, if the invasion is not very big, it might not show in your photos. I've used lenses with all kinds of crap in them without it causing a problem. It just depends on how much fungus there is, and how much other stuff like dust is accompanying it. Don't store lenses in the leather cases, it's a perfect breeding ground for fungus. Keep your lenses in a dry place.

Good luck.

That could happen.  Probably best to get a "black light" bulb, and make a box to mount it all in (with ventilation to keep the heat from the bulb building up).

PF