M lens education needed

[ALScott]

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So I am new to the M series.  I just picked up another 35 lux and there were black flakes, maybe grease, around the tube part holding the rear element.  They were not on the glass but the outside of the black metal around the glass, the bit that sticks out of the rear of the lens some.  Anybody have any idea what that could be?  Should it be there? Is that common/normal?  It was large enough for me to see and I assume could have fallen into the camera which cannot possibly be good.  What's the name of that part of the lens?  

[LocalHero1953]

Matte black anti-reflective paint from inside the barrel? You might be able to see where it comes from.

Edited September 15, 2024 by LocalHero1953

[69xchange]

A picture would be useful here

[ALScott]

I saw the flakes or whatever where the q-tip is touching.  You can see the goo on the q-tip.  There are some bits around in the other pics I can't get to.

 

 

 

 

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Edited September 15, 2024 by ALScott

[69xchange]

The helicoid is greased for smooth operation of the focus system and usually that attracts dirt which eventually builds up. It is normal to see the helicoid grease from the rear.

My assumption is that the black “flakes” are either dried grease or dirt that has been accumulated over the years and mitigated to the rear element outer case? It doesn’t hurt to wipe off the excess with Q tip like what you are doing. 

Edited September 15, 2024 by 69xchange

[newtoleica]

Looks like grease on the helicoid to me that’s picked up a litte bit of dirt. There will be grease there as the RF coupler needs it. I never look that closely round the back of the lens myself….. 

[ALScott]

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34 minutes ago, newtoleica said:

 I never look that closely round the back of the lens myself….. 

That may be what I need to start doing too!😁