cleaning a Hoya CPL

I have a Hoya CPL that I tried using a couple times but never got the hang of it and considering I do mostly avian photography it's not the most useful tool in my bag. I'd like to sell it but it's covered in smudges. . . I think it got a little smudge on it so I tried wiping it with a lens cloth and it made it worse. Can anyone tell me how to clean this thing?

Also, if you are interested in buying it (and want to clean it yourself) I'd give a nice discount. Hoya Pro1 CPL

Thanks

Luke,

From your desciption, this is an 'oily' smudge. Removing it will likely take a non-amonia-based cleaner. A tiny drop of isopropyl alcohol on a dampened microfiber cloth will probably remove the spot without harming the coating. Don't allow any liquid to flow into the mount. Follow the spot cleaning with a wipedown using a dry microfiber cloth. That should do it.

--P

I don’t know much about Hoya, but I had the same problem with my B+W. I could not remove the smudges even using a lens cloth and cleaner kit. The B+W rep told me to use isopropyl alcohol. Like Preston wrote, just a little bit on the cloth (not on the filter) will do the trick. This is all I use now.

Excessive failed attempts with the wrong tools may damage the surface.

Jeez, all this time I thought I was the only one who had problems cleaning a filter!

I use B+Ws now which are somewhat easier to clean, but the one Hoya Digital I still have is my 82mm CPL because I'm out of home equity room in order to obtain the B+W, lol. SO, I know your struggle with trying to clean that thing. The best results I get are when using Ivory Dish Soap & water with a soft rag, in circular motion, and then drying it with a regular Bounty kitchen napkin. This will leave a clean glass but with a lot of lint from the paper napkin. I remove that with a blower bulb, and then a loosly bunched microfiber cloth, used lightly like a feather duster. THEN when it's all clean, I put it in the case and never pull it out again so I don't have to go through all that any more.