How to clean an IR cut filter?

[Timmyjoe]

I've got Leica UV/IR cut filters for the Leica lenses I use on my M8. I noticed that two of them look kind of cloudy, even though they are both fairly new. I tried to clean one of them and boy did it make it a mess. Is there some specific procedure for cleaning these?

I first used a Giottos rocket blower to blow it off, then tried to use the old "breathe on the filter followed by lens tissue" method. Man, did that ever make it a smeary mess. When you slide the lens tissue across the lens surface, it feels rough. I finallly used some special lens cleaning fluid I use for cinema lenses, and that made it somewhat better, but I am wondering if there's some kind of sprayed on coating that maybe I removed by trying to clean it with lens tissue.

Does anyone know the proper way to clean these filters?

Thanks for any and all input.

Best,
-Tim

[jaapv]

No - these filters are not coated, as such, but are made up of a multitude of interference filter layers. I would try Eclipse 2.

[Vickko]

You need to use solvent. Hasselblad / Zeiss used to standardize on Windex. Kodak lens cleaner is also good, and ROR (http://www.ror.net/) is also good.

Breathing on the filter unfortunately deposits a coating of water, and, if you are unlucky, saliva, which will just smear onto the filter.

Or go here, if you want to go "all the way": http://lenses.zeiss.com/photo/en_DE/..._products.html


The method is to:
1. blow off the surface that you want to clean to get rid of dust

2. moisten a cleaning tissue with fluid and wipe it all over the surface, gently

3. with a clean tissue, dry off the surface, gently

4. do NOT touch the surface of the tissue that will come in contact with the glass, with your fingers. If you do, you'll just transfer your fingertip skin oil onto the glass and ruin the efforts. This means that you must only touch the tissue at the edges, including if you have to roll or fold it up into a more manageable wad

Have fun

Vick

[Timmyjoe]

Originally Posted by Vickko

You need to use solvent. Hasselblad / Zeiss used to standardize on Windex. Kodak lens cleaner is also good, and ROR (http://www.ror.net/) is also good.

Yeah Vick, ROR is what I used, with Kodak/Tiffen lens tissues. So that's not going to hurt the Leica UV/IR cut filters?

Can't understand that slightly gritty feeling the filter had though. Really odd.

Thanks for everyone's input.

Best,
-Tim

[AncientCityPhoto]

I would use Eclipse fluid and a PEC pad or microfiber. That is probably the gentlest and most effective way I have found to date. I also use that to clean fingerprints off of the rangefinder and viewfinder windows.

[Ben Z]

The Leica and B+W 486 filters don't have the scratch-resistant multicoating, and scratch very easily if there's any specs of grit on them when you wipe, no matter what cloth you use or if you use liquid or not. When I had the M8, on lenses I used those filters I ended up putting a B+W MRC protective filter on top of them! (I never got any flare, but it was pure luck of the draw). Eventually I replaced all the filters with the Heliopan brand, which are resistant coated. Those I could breathe on and wipe with my shirttail and nothing bad ever happened.

[Timmyjoe]

I tried ROR, Kodak Lens Cleaner, and Isopropyl alcohol, and they all worked about the same. Took alot of work to remove ALL of the smearies.

Noticed with the E46 filter, even when I got it spotlessly clean, when you shine a bright light through it from an angle, the whole filter is hazy, like it's covered in a light haze. It's completely uniform, just weird. When you look straight through it, or shine the bright light straight through it, you don't notice it, but when the bright light is coming in directly from an angle, then you can really see it.

Anyway, thanks for the advice everyone. All three filters are now clean. Hope I don't have to clean them again anytime soon.

Best,
-Tim