Un removable specks on B+W UV filter

Hi guys, I wonder if anyone has come across this before. I was shooting with my 70-200 today and was not getting very sharp results, thought I was a bit out of practice. Turns out theres funny specks on my UV filter that I cannot remove.
Does anyone know what this is? I store my gear in a pelican case with Silicone desiccant and a gauge and keep it around 50% RH.
I wouldn't have thought this would happen with a relatively expensive filter. I wonder if I should take it back, although it's 3 yrs old now.

Check this thread https://photography-on-the.net/forum/showthre​ad.php?t=730285.

The B&W filters here have extensive warranties, 5 or 10 years as I recall and that is one of the things built into the price. I'd return it for a replacement, you are probably entitled to it. Check first with your local importer for the procedure.

If you put some breathe on it and use the soft padded side of a LensPen those dont come off?!

John from PA wrote in post #16400602
Check this thread https://photography-on-the.net/forum/showthre​ad.php?t=730285.

The B&W filters here have extensive warranties, 5 or 10 years as I recall and that is one of the things built into the price. I'd return it for a replacement, you are probably entitled to it. Check first with your local importer for the procedure.

Thanks, I'll check that out and I'll be going to the shop where I brought them from this week. I'll let you know how I get on.

ben_r_ wrote in post #16400934
If you put some breathe on it and use the soft padded side of a LensPen those dont come off?!

Nope, I always use lens cleaning fluid and lens tissues or a micro fibre cloth. This looks like it's inside the glass.