Hi! I just got a low priced (about 20 Euro, sent) Kenko 52mm CPL filter, from what it seems a reputable eBay seller. The filter is the non multicoated type, so the price was reasonable: low but not "suspect". Here's a pic found on the net of the same model, just as a reference: The item was of course quoted as "new": it had two small, a bit anonymous, silver seals on the side, that kept the flimsy plastic box closed. I was surprised to see that the filter was not clean at all: some dust, and also some "greasy" like smudges. All become clear with a Lenspen, but still... My question is: is this common / to be expected with cheap / low price filters? Or I have to suspect that it wasn't new? Thanks!