Help! Strange oil layer was found in my lens

[Hercules Fu]

:( I hand carried my lens case with me on plane from HongKong to Taiwan,when i arrived Taiwan(which is really colder than HongKong for approx. 4-6 degree and more humid) i find that all my lens have a strange oil layer which occupied ''only'' 75% of the surface of the front and rear piece of the lens(it's the most weird part).

 

I think that it was a fog layer due to temperature change, so i leave my lens case opened to reduce the fog, but it fail( I did this for a whole day). Then i try to clean the oil layer with the Tiffen lens tissue, chamois cloth, micro-fibre lens cloth, it fail again, when ever i clean the oil layer, it disappear for about 3-5seconds, and it come back again.

 

Finally, I try to clean it with kodak lens cleaner, it seems to works better, but after half a day, the oil layer come back again.

 

The oil layer is not visible without a flashlight, i tried to look through the lens with a light bulb, it's not visible too. When to flashlight is lighting the lens with a back side light, the oil layer become extremely visible, and the circular pattern will change if i clean it with a cloth.

 

Does anyone encounter such kind of problem before? I've no more idea on how to clean this strange oil layer anymore! :( (I don't want to clean it with 99% alcohol)

 

*some additional detail, there is one lens without oil layer and it's a new Canon Zoom lens(EF mount), and all the lens suffering now are Nikon AI old mf lens

Edited November 16, 2009 by Hercules Fu

[Bernie O'Doherty]

The oil layer is most likely coming from the lens interior. Perhaps a technician used too much lubrication in the interior at one time. He also may have used the wrong viscosity level. See if you can find a good lens technician in your country and have him (or her) disassemble and clean the interior thoroughly. A little lens grease goes a long way.

[Hercules Fu]

The oil layer is most likely coming from the lens interior. Perhaps a technician used too much lubrication in the interior at one time. He also may have used the wrong viscosity level. See if you can find a good lens technician in your country and have him (or her) disassemble and clean the interior thoroughly. A little lens grease goes a long way.

 

But all the lenses were in good conidtion in HongKong, i double check them one by one, is that cause by temperature change?

[Russell Richard Fowler]

I had similar problems from a lens that had just been serviced. The cabin pressure change during flight, which make your ears pop, was enough to have the lens lubricant creep.

 

 

quote name='Hercules Fu' date='Nov 16 2009, 06:56 PM' post='306061']

But all the lenses were in good conidtion in HongKong, i double check them one by one, is that cause by temperature change?

[Olex Kalynychenko]

The oil layer is most likely coming from the lens interior. Perhaps a technician used too much lubrication in the interior at one time. He also may have used the wrong viscosity level. See if you can find a good lens technician in your country and have him (or her) disassemble and clean the interior thoroughly. A little lens grease goes a long way.

 

I support of this idea, but, the owner do not say any about full name of lens, fix or zoom and other.

It's a metal body or plastic body of lens ?

If we told about prime lens the lens must have waterproof front and rear optical blocks before and after aperture mechnaism.

The mechanism of aperture control can be re-lube and oil can ingress on glass surface.

My other idea - moist (humid air) inside waterproof optical block.

But, it's can be , if you carry lens from cold ( -5..10 C ) to indoor.

 

Yes, of course, need optical technician for inspect of lens.

If this oil on glass surface, need professional optical cleaning and do not destroy of MC.