lens mount rust?

[Shibang]

Hi All,

Has anybody any advise what I can do here?

I noticed on my lens mount some brown marks. At first I thought rust but it is not like rust that I know but might just be the start of it.

It could also pass as some kind of oil based substance or grime.

Does this look like something I might be able to clean?

Regards


20121112-DSC_1807 by G-Lang, on Flickr

[groovesection]

It is certainly not rust mate
I am no metallurgist but that looks like Aluminum to me and as far as i know Aluminum is non corrosive (does not rust).

[Manfred M]

It is likely one of two things; either an accumulation of contaminants (dirt) on the lens mount. If you rub it with your finger and it comes off, you'll know that this is what it is. If it is an older lens. then these often used brass lens mounts with a hard chrome electroplated finish. With use the chrome plating wears off and exposes the brass underneath. Looking at where you see the colour is where you would expect rubbing of the mating surfaces of the lens / lens mount, so this is possibly what is happening as well.

[DanK]

I agree with Manfred--it looks like worn-off plating. It does not look at all like rust.

[Shibang]

Thanks for the comments.

Do you think this would this reduce the resell value of the lens?

The lens is the Nikon 17-55 2.8, I was planning on selling it and I noticed then when taking a few shots of it.

Regards,

[Manfred M]

It is certainly not rust mate
I am no metallurgist but that looks like Aluminum to me and as far as i know Aluminum is non corrosive (does not rust).

It's unlikely aluminum, as that metal is too soft to be used in something like a lens mount. In lenses it tends to be used in the lens barrel and in the exterior components, although engineered resins are very much the norm in newer lenses. Alumimum has more of a white colour from the aluminum oxide that forms when aluminum is exposed to the oxygen in air.

[Shibang]

One site I looked at said it was brass and chome so I guess it is the brass I can see

[Melkus]

Looks like normal wear and tear where as the lens has been put on and tooken off again. As long as the lens is working that should on affect the re-sell of it. Only when a lens start getting scuff marks on the body, scratchs on the glass or problems with the aperture blades, (oil on them, sticking etc) dose it start loosing value.

[Glenn NK]

Whatever it is (rust, guck, or worn parts), it's not a bad idea to clean these parts occasionally with a Q-tip. Moisten the cotton with a bit of isopropyl alcohol.

I have some 99 percent pure isopropyl alcohol that's used for this purpose (it's also used on my printer/scanner to remove guck that will show up on a scan). Some drugstores handle it - but DO NOT use rubbing alcohol which also contains isoprop plus some other undesirable additives. Get the good stuff, when not in use, store it with the cap down and it will last a long time. It's also one of the ingredients in some purpose made sensor cleaning fluids.

I think that one could also safely use liquid lens cleaner.

I also think that Manfred has it right about the material.

Glenn

[oleleclos]

One site I looked at said it was brass and chome so I guess it is the brass I can see

Yep, the same marks you get on camera bodies when the chrome or enamel wears off on edges and corners. Often called "brassing" because what used to be underneath was brass, so that's what shows through. On modern cameras it's more likely to be tiatnium or some other fancy stuff.