Filter cleaning time

[barx1963 (Malcolm)]

I have a couple of filters, not expensive ones just Bintel OIII and UHC, but still not cheap! After a year or so of pretty constant use, dropping in grass on dewey night, accidentally touching etc, they have gotten fairly grotty.
Any suggestions for cleaning? I have a blower and a lens pen (yes a proper one!) or do I need to do something special?

[pgc hunter]

I have an OIII that was stained when I purchased it new from Bintel, they cleaned it free of charge. Try asking them.

[mill (Martin)]

Filters are pretty sturdy.
I clean mine with some eyeglass fluid from the optician and a facial tissue, works every time.

[Saturnine (Jeff)]

Hi Guys

I semi regularly clean my filters, about once a year, just clean them as you would your eyepieces, gently.
Beware that some of the coatings maybe a bit soft so first, blow off any grit and dust and gently wipe with a lens brush then wipe softly with an cotton bud dipped in lens cleaning solution then gently pat dry with an lens tissue. That's it, pretty easy really, gently does it at all times though.

Regards

Jeff

[floyd_2 (Dean)]

I clean filters the same as I clean eyepieces. First, use a blower to remove any particles that you can. Then I use a lense brush to gently remove any other particles that didn't get the hint with the blower brush.

At that point, most of the grit that could do damage to your filter should be gone. I make three tear drop shaped pieces of cotton wool and set them aside. I put a couple of drops of pure isopropyl alcohol on the first piece of cotton wool (on the big end, holding the small end) and clean the filter gently. I then immediately grab the second piece of cotton wool and dry the filter before the alcohol can dry out (and deposit any grime that was in solution back onto the filter). After that, I breathe on the filter, and clean the moisture off the lense with the third piece of cotton wool.

I get perfectly clean eyepieces and filters using that method. Be careful to only use a couple of drops of isopropyl though, especially on lenses. You don't want any fluid finding its way into the edge of the lense etc.

Clean your filter gently, patiently and methodically, and never re use any cotton wool and you won't go wrong.

Dean