*********THIS IS NOT A THREAD INTENDED TO FIRE UP THE DEBATE - JUST MY PERSONAL EXPERIENCE*********
I know this topic is against the Warsaw Treaty to bring up, and has been beaten to death, but I just wanted to share.
Today I did something many folks might cringe at - I set up my camera with my Rokinon fisheye in a box at the park in a way that I knew would run the risk of the lens being pecked by many beaks. My goal was to get a shot looking up at a bunch of ibis's feeding all around the lens.
I took a small cardboard box, cut a hole in the top to allow just the lens front to show, and used a wireless remote (Shutterboss). Didn't take long to get the birds to come over, and they did eat off the box (hamburger buns), but I didn't get the actual shot I was hoping for (full circle of birds feeding around the lens). What I did get was a lot of birds pecking at the box, and the lens, as the wind was blowing crumbs onto the lens. I could hear the beaks hitting the lens on at least 10 occasions from about 7 feet away, and in honesty, it made me cringe. When it was all said and done, not a scratch, scuff, nick, blemish or anything on the lens or the coating.
I've taken old lenses and dropped things on them like pilot-tipped drill bits to see how they hold up with and without 'protective' filters, but I've never had a 'real-world' situation that most would think would cause damage. Today just really re-confirmed my belief that even in 'hazardous' situations, a filter is not necessary. On a side-note, I live in Florida, near the beach, which has salt water, and I go to the beach quite often, and I don't use a filter there either.
BUT - TO EACH HIS OWN. I'm not trying to start the war, just relaying my personal experience.
Here's one of the shots I got where the bird hit the lens -

RAVE
RAGE
RAGE
I fear fingerprints, dirt and everything else, never considered a threat of wild Ibis's attacking my lens.

