Ok, I'd like to preface this by saying that : 1. I am generally very OCD about keeping my equipment in the same condition that I bought it. Cameras, cars, laptops, lenses; I like to treat them all with respect. 2. Since buying the Nocticron I have stored it in its pouch with the reversable lens hood mounted and screwed on in reverse (not overly tightened or so I thought). 3. The Nocticron has been kept stored in a LowePro Video 250W backpack in a padded compartment all to itself in the back of my ward-robe. Like I say I try and take care of my stuff. I took the Nocticron out at the weekend only to discover that there are now little scuff/markings around where the lens hood mounts to the barrel. Perhaps I over tightened the screw when storing the hood in reverse and putting it in the pouch. Perhaps while my backpack was in the boot of my car and I went over a bump or something it caused something else to push up against the bag etc... Whatever and however it happened, the lens has a slight but noticeable scuffing there now that wasn't there a few weeks back. I'm not really a happy camper! It doesn't affect the optics and other than the markings around the top of the lens barrel, the lens is prestine. Those of you here that I have spent 1600 dollars on this lens will probably not be very happy to find little scuffs on it a few weeks later! So make sure you don't make the same mistake that I made by over-tightening or storing the lens hood in reverse :/ My advice, store screw type lens hoods separately. Kinda obvious in hind sight.