I just got a 77mm Hoya UV filter. As soon as I pulled it out of the plastic case I noticed a piece of something stuck to it, about the size of a dust particle. I gently blew on it, and it didn't budge so I then took a new post-it note, bent it, and used the edge to gently dislodge the debris, and no I didn't get sticky stuff anywhere near the lense. Anyway, the little booger or whatever it was left a very small smudge. Now it was time to quit playing around- so I put a drop of lense cleaning solution on a pec pad and (ever so gently of course) went to town on the smudge. The smudge was quickly gone but now to my dismay my filter had become a streaky prismatic mess. I did the natural thing whenever one has a problem in life, and googled- and it seems I wasnt the only one to ever encounter this phenomenon. Unfortunately there was a wide range of input on the subject (both wet and dry) ranging from breath and a t-shirt to lense pens. After repeated attempts I was eventually able get the new filter looking... well -almost- new again. *sigh* There are still a few streaks near the edges, and I'm sure since they're so far from the sensor they'll have no impact on the photos, but nevertheless is there a more bulletproof way to get these UV filters clean? In hindsight my first intervention after getting that little smudge would have been a dry pec pad or a qtip. The lense cleaning solution was a bad idea. There is definitely an art form to swabbing the filter with a wet pad with enough solution on it, then using a dry-oil free- NEW pad in circular motions, moving outward, ...but then there's the edges of the glass next to the metal frame which are hard to get to. Any misstep of course makes a new smear. It's like a rubiks cube, you get one smear off and make a new one. Any thoughts?