I have heard many complaints about the lens hood for the 12-40 2.8, and have experienced the shortcomings myself. On first examination, the hood seems to be substantial and well-engineered. The two release buttons give the impression that the hood will be securely locked to the lens and not easily lost. Nothing could be further from the truth. In practice, only one button at a time does anything. One locks when the hood is in the shooting position and the other one locks it in the stowed, reversed position. The buttons protrude 2mm from the hood and the springs are relatively weak. The end result is that if the button knocks, even lightly, against your body, the lens hood will detach very easily. I "lost" (and luckily found) mine about 4 times before I decided that I needed to fix the problem. I actually took the hood apart to see how the mechanism worked, but it is not necessary to dismantle it to achieve a cure. What you need to do is to turn this: [/url]LH1-1.jpg by Roger OZ, on Flickr[/IMG] Into this: [/url]LH2-1.jpg by Roger OZ, on Flickr[/IMG] Apply 2-3 layers of masking tape around the buttons to protect the hood from possible damage: [/url]LH3-1.jpg by Roger OZ, on Flickr[/IMG] Using sandpaper, files, or preferably a "Dremel"-type tool, trim at least one to two mm from the buttons to make them almost flush with the masking tape. Finish off with fine sandpaper and remove the masking tape. You will now find that the buttons are still easy to press in enough to release the hood, but they will NOT be released accidentally. If you remove the full 2mm protrusion of the button, you will find that you are left with a rectangular hole in the centre of the button, as in the photo. If you remove only 1mm you will avoid making the hole, but at a slight loss of security. I modified my hood this way about one month ago and since then, using the camera every day, I have never had the hood detach unexpectedly. TNew hoods are anything from $35 to $80, so it's a simple solution that costs nothing. Roger Allison-Jones.