Clean needed for Nikon 50mm

[yashica1943]

I have just received from a seller in Japan (who I had used before) a Nikon Nikkor - S Auto 50mm f1.4 lens which unfortunately has fungus inside the rear element. I intend to keep it but need to find someone in the UK to clean it properly and economically. (Cheap!)

Apart from that it is in excellent condition.

I have contacted the seller and I am awaiting a reply about the condition and some sort of refund.

[yashica1943]

The continuation of this is that the seller grudgingly gave me the 50% refund that I demanded, got nasty and told me not to buy anything off him ever again! This is after I had given him excellent feedback for the two camera bodies that he had sold me before. The fungus consists of blobs covering the whole surface of the rear element with some misty filaments on one side. Described as 'there are a little thin fungus'!
After looking very hard through a loupe and taking macro pictures of the lens I have decided that the fungus is on the outside - but is white, thin and cannot be removed with a gentle application of ordinary lens cleaner.
Perhaps somebody with more knowledge could explain if this is damage? Could it be removed/ improved with an application of peroxide?
If I have no luck with this at least the outside and front of this 40+ year old lens looks good and was cheap.
I have given up trying to load photos so I cannot show the effect.

[raybar]

I don't have a specific suggestion for this particular problem, since I can't be certain what is on your lens.

In similar situations, I try different solvents until I find one that helps. Presently within reach are 
- water
- household cleaners (Windex, bleach, 409, Mr. Clean Multi-surface)
- alcohol
- petroleum distillates (naphtha and paint thinner)
- acetone
- trichloroethylene (sold as Picrin dry cleaning "spotting" fluid) 

Whatever is on your lens, something will dissolve it. But move cautiously because there is always the risk of making things worse, and you don't want anything to get inside the lens. And, as always, use with adequate ventilation or work outdoors.

[yashica1943]

Thanks for the reply. I have looked very closely at the lens and taken macro photos of it. The difficulty is that the marks are fungal, and are difficult to focus on because they are naturally 'fuzzy'. They are white but from a distance of a few inches they appear to be round and fairly solid. I have tried 6% hydrogen peroxide with no success. I am wondering if it is etched into the lens but running a fingernail gently over the surface it feels smooth, except for a small unconnected scratch that is very difficult to see with a loupe! Might give up on it and keep it for show as it is a very smart looking thing.

[raybar]

Yes. Just keeping it as a display piece is often the best course of action. But before giving up, you might try a few more solvents - whatever you have on hand.

Hydrogen peroxide just releases oxygen atoms ( H₂O₂ + energy >>> H₂O + O ). At a 6% concentration, nothing much will happen unless you apply it for a long time. And really, between lens cleaner and peroxide, you have mostly just tried water

I hesitate to suggest this, and didn't include it in my list of solvents, because it carries some risk to both the lens and yourself, but you might try a solution of sodium hydroxide (sometimes called caustic soda or lye). Something of a last resort, you might say. I get it as a drain cleaner, and use it mostly for that, but also for removing baked on grease from old cast iron cookware. (Soak overnight, scrub a bit, repeat until satisfied). For a little job like a lens element, I dissolve a couple crystals in an ounce (a shot glass, actually) of COLD water (releases heat and "mists" as it reacts with water), and apply it cautiously with a cotton swab. Afterwards, a wipe with vinegar (acid to neutralize the alkaline), and finally clean water or lens cleaner or whatever you typically use. 

CAUTION - - A strong solution is extremely alkaline and will dissolve almost anything organic, like fungus, or your skin if you don't rinse it off right away, or your lungs if you inhale vapors. It can also attack certain metals (aluminum, lead, and zinc are often listed on the container). Best to wear rubber gloves and eye protection, although I usually don't and just work carefully. But proper ventilation is a must. Work outdoors or right in front of an exhaust fan.  

[yashica1943]

Thanks, I have decided to leave it. I have a few other old quality manual 50mm lenses with cheap adapters to fit on my two CSC's one of which is permanently converted to infrared. Thanks again.