Ok with further research I got the following infos...:
1. The Nisi Nano filters are coated which makes them more prone to scratches. They also seem to go towards magenta/red.
2. The Firecrest IRND filters have the coating in between the glasse which supposedly make them more durarble.
and questions:
1. Does the Nisi filters waterresistance really work in pratice?
2. I read about the firecrest ultra but couldn't find any infos wether they are IR resistant? Are they?
3. How about the Lee Proglass IRND. Outside Coating or in between the class?
4. Most reviews are about the 10-stoppers. I don't care about these. Can I go wrong with low stop NDs with any of these brands?
When spending so much on glass durability is very important to me. So scratch resistance is of essence.
Thanks for commenting.
Cheers
Hello,
if it interests you, I tested many filters and found that the Firecrest were the best. Back then, Haida and NiSi were not around, you can see my results here:
BEST FILTERS FOR LANDSCAPE PHOTOGRAPHY REVIEWAs far as neutrality, I think Firecrest, NiSi and Haida are better than the others; personally, I prefer the FH (Disclaimer: I am a Formatt-Hitech Ambassador and Featured Artist. The review above, however, I wrote prior to becoming an Ambassador). The reason why I prefer them is, as you mentioned, durability: the Firecrest and Firecrest Ultra have the coating in between two thin panes of glass, making them much more scratch-prone than any other filter. More, the new Ultra have been improved further by using a cinematic glass polishing technique (don't ask, but you'll find info on FH blog!), which makes them much sharper than the older Firecrest, and much sharper than anything else using long lenses.
The reason for this is that long lenses, say over 70-80mm, might show local lack of sharpness in some area of the image due to the (invisible) "ripples" on regular filters' surfaces. These "ripples" don't get picked up by Wide-Angles and normal lenses, but they affect longer lenses. I am not a tech guy, so I hope this makes sense - all I know is that my Ultras are MUCH better than the older Firecrest for tele lenses.
Hope this helps, best regards
Vieri