Hoya 67mm HMC NDX400 Screw-in Filter

I recently purchased one of the Hoya NDX400 ND filters. This after reading reports that although a good filter, the main problem was cleaning it, especially when drops of water get on it. As this filter is going to be used near water a lot for blurring waterfalls etc, this does seem to be a problem. I emailed Hoya and they answered quite quickly to say that 'Please clean with a lens cleaner in the same way as a lens. It's possible to use dehydrated alcohol.
When a splash of water adhere to a filter, please wipe it off as soon as possible.

I have a bottle of Baader Wonder Fluid and am not sure what's in it or whether or not it would damage the filter. Some reports suggest that the coating on the filter comes off during cleaning (I am not sure what they were using). I find this a little hard to believe with modern multi coatings.

Has anyone had any experience with this type of filter, I am afraid to clean it just in case.

Thanks and merry xmas to all

Brian

meddyliol said:

I recently purchased one of the Hoya NDX400 ND filters...

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I've never had an issue cleaning my filters using denatured alcohol (I think your pen pal typo'ed there); do not try substituting rubbing alcohol. I've not heard of Baader Wonder Fluid so I can't say what it would do to a filter. For around $8, though, your local hardware store will happily sell you a quart of denatured alcohol, a lifetime supply for most us probably.

Another great tool for keeping your kit clean are these 4" x 4" Pec Pads. Every photographer should have some of these in the bag for routine cleaning chores.

Last night i went out to shoot a sunset on the lake. The winds were 30+mph and i got down close to the water and paid the price. I went back to the truck and took off the ndx400 filter and tried to clean it with just a lens cloth. It did not work except to get the droplets off the glass - the spots remained. When i got home i used Giottos multi purpose cleaner and a lens cloth and had to work at it much harder than i wanted to get the spots off. I never did get it as clean as it was before. As hard as i have wiped on the glass i'm pretty sure it won't clean up like new anymore.
My point of this is to find something that works ahead of time if you can. The ndx400 for 82mm glass ain't cheap and wish i would have been prepared. Just thought i would share. I'm going to pick up some denatured as Paul suggested and give that a try.

Thanks for your replies. I will try and get some of that denatured alcohol but I don't know if I can get some in the UK.
I have just found out that it might be the same as methylated spirits in the UK which is very cheap although a purple colour. Another, maybe better alternative is Iso-propyl alcohol which is again available in the UK. I have just ordered 100ml of Iso-propyl alcohol from ebay for £3.99 post free.