My Lee 9 stop soft grad filter has a few scuffs and scratches after three years of use. Any way to buff these out or otherwise repair them? Or is this a case of "just replace it?"
Lenses with 77mm front elements or larger, can be polished to correct scratches, instead of spending thousands of dollars on a new lens. But a filter is very thin glass, and it would be difficult to polishing, and then make new anti reflective coatings.
If the image quality is affected, you must replace with a new filter.
Filters should have no effect on the path of light. Therefore, the two surfaces need to be parallel and smooth. That's a job for an expensive machine, the repair would be super pricey if you can find someone with the machine.
My understanding of ND grads is that the stuff is on one surface, so only half is "repairable".
Some things are just not repairable.
Watch the YouTube video on their making and you will see they are hand dipped. This is why Lee doesn't offer a reverse grad.
Sadly mine are scratched as well but I can't find that it makes a difference.
So no, I am pretty sure they can't be polished.
please read this:
http://kurtmunger.com/dirty_lens_articleid35.html
If only half of this is true, you do not have to worry about scratches on filters.
I know that the guy is nuts, but it shows how much dirt/damage you can have on the front of the lens.
The opposite is true, even small dust particles on the rear of the lens will definitely show up.
Suggest that you try it with and without the filter.
I use the Lee filters a lot on the beach and I get a lot of salt, sand and seawater particles on them and I hardly notice it on the final pics.
Scratched filter? If you can tangibly demonstrate a loss of IQ or visible artifacts ie flare then I'm afraid it's new filter time. It's part of a filter's job as far as I can see. Without the filter it's your lens front element that would have taken the hit.
A touch OT...This is the original quick and dirty...in daily newspaper darkrooms it was not unknown to pop a bit of forehead grease onto a scratched negative. Worked like a charm. Too bad if it was an archive level hero! Of course I don't behave like that any more, and I suspect forehead oil isn't going to add anything special to a scratched filter.
From the few things I've tried polishing, my experience is that you can make the scratch less visible, but at the price of rounding the edges next to the scratch, so it becomes more fuzzy over a larger surface. Something like whitening toothpaste is designed to create smaller and smaller particles while being rubbed and usually works quite well if you want to lessen a scratch in plastics.
Bummer that it can't be repaired. It's pretty scuffed after a few years of pretty intense use. It's been a good friend to me, but I think it might be time to replace it. Thanks all!