Instruct: Classify Amazon reviews into positive or negative sentiment
Query: The first one worked well, but...

The first one I purchased worked like a charm, even though the custom B+W lens cap would fall off while stored inside my camera bag (FYI a normal lens cap will not fit over this filter) thus the filter apparantly received a few scratches from scraping other equipment inside my bag. Now, after shelling out an extra hundred bucks to replace the first one (which was almost brand new) its identical replacement has a colder blue cast in the glass... They don't even match!!!So, besides the useless lenscap which never stays on, I seriously question the scratch resistance of the glass and B+W's quality control, hence the two different colored filters I have sitting right in front of me. I know B+W is supposed to have a great reputation, but my own opinion has been swayed. I just hope I don't have any problems with the return of this item.