Earlier this summer there were complaints on a couple micro four-thirds related forums that the hood that came with the rather fabulous-but-spendy Panasonic Lumix Leica 42.5mm f/1.2 Nocticron lens was emitting a hard, rubber cement-like glue onto the lens barrel itself. I was one of the affected.

The glue seemed to be seeping out from under the tightening ring that surrounds the inside of the hood. First of all, these stupid screw on lens hoods are the dumbest design ever, and I had agreed with another forum member that whoever came up with this style of attaching hoods (as opposed to twisting the hood on bayonet style) should be shot. To me, it offers the potential for bad things as leaving marks/scratches (as it did to my Olympus 75mm/1.8 lens--same stupid screw-on style lens hood by JJC) when it is accidentally pulled off by something/someone. ANYWAY that's another topic.

About a couple months after I received my PL 42.5mm lens, I noticed a mark that I thought was left by one of my friends attempting to twist the hood off as if it were bayonet style (imagine my horror as I watched this!). Not having inspected it closely, I thought it was a scratch. Then over the next few weeks, more of these marks showed up! I started picking at it, and thought it was cheap black paint melting off the lens barrel! After more picking at this hard, gluey substance and inspecting around, I saw that the culprit was the leaking/seeping glue inside the hood.

Recently, I finally made time to see if I could clean the stuff off the lens:

Another view in different light. Cameo appearance by my Microsoft Surface Pro 2.

Inside the lens hood. You can see the tightening ring at the rear.

Different light: see those "scuff" marks?  Those are actually glue residue. The glue would seep out from under those "strips" over time and onto the lens barrel. Pulling the hood on and off the barrel left extra residue back on top of the "stri… — Different light: see those "scuff" marks? Those are actually glue residue. The glue would seep out from under those "strips" over time and onto the lens barrel. Pulling the hood on and off the barrel left extra residue back on top of the "strips."

Armed with alcohol swabs and a microfiber cloth, I took a deep breath, said a prayer, and began my clean up work...

After about 20 minutes, it worked!  Looks about as good as new. — After about 20 minutes, it worked! Looks about as good as new.

Now if Panny would make this lens a twisty bayonet style, then this glue problem wouldn't exist, would it?? Although I was able to clean my lens (thankfully), there is still minor residue from inside the lens hood (I was able to clean it up as well). But who knows if this is a long-term problem that will keep persisting over the length of ownership? My point is, for a $1600 pro lens, this is unacceptable, and I'm definitely not an isolated case. >:(

UPDATE (October 10th, 2014): Alan from Panasonic has immediately reached out to me to help resolve my issue. Good on Panasonic!

UPDATE 2 (Oct/Nov 2014): Panasonic sent me a UPS shipping label to ship back the lens. I was a bit nervous since it was superb optically--the problem was only for the hood-- and sending the entire expensive lens seemed a bit overkill. But I did as was told and sent it in. In three weeks flat, I received the lens back, although as you will see in the update photos below, it came with a nice fingerprint on the front element:

The lens worked fine as it always did, and yes I even checked that it was the exact same lens I had sent out. In the remaining time that I owned the lens up until late Summer 2015, it served me very well with no more glue leaking problems. I was sad to see it go, I hope to own it again someday if I ever win the lottery.