Can't loosen filter

I stacked a ND filter onto the what I always have on my 100-400 and now I can"t get it to unscrew. They're stuck tight. First time this has happened and the first I've this ND filter. I tried putting them in the fridge hoping one would contract faster than the other, but no luck. Anyone have a solution?

Have you tried putting a rubber band around the filter? I may give you a little bit more grip and leverage to help loosen it.

3Rotor wrote in post #18439916
Have you tried putting a rubber band around the filter? I may give you a little bit more grip and leverage to help loosen it.

You beat me to it! Good luck with the filter.

When filters get stuck, many times it is because they have become cross threaded. I slight bump is usually enough to do so. If you closely examine the seam between the filters and look for the spot that is a little closer than the rest of the seam. It takes a little looking as the threads are pretty fine. When you find that spot, place a knife blade in the center of the cross thread and gently twist the knife so that pressure is applied on both filters. Sometimes you can hear, or feel, a very subtle tick as the threads pop in. It should now unscrew normally.

If the filter is stuck because it is screwed on too tightly, the rubber band method or a filter wrench works well.

4huskers wrote in post #18439912
I tried putting them in the fridge hoping one would contract faster than the other, but no luck. Anyone have a solution?

Put an ice cube in a plastic bag & apply it to the ND filter so it gets colder than the lens.
When you get it off, use a pencil to apply some graphite to the threads.

gjl711 wrote in post #18439932
When filters get stuck, many times it is because they have become cross threaded. I slight bump is usually enough to do so. If you closely examine the seam between the filters and look for the spot that is a little closer than the rest of the seam. It takes a little looking as the threads are pretty fine. When you find that spot, place a knife blade in the center of the cross thread and gently twist the knife so that pressure is applied on both filters. Sometimes you can hear, or feel, a very subtle tick as the threads pop in. It should now unscrew normally.

If the filter is stuck because it is screwed on too tightly, the rubber band method or a filter wrench works well.

Agreed.

If they're not cross threaded or jammed together some other way, the rubber band method can work well. The only caveat is if they're binding because they're not staying circular enough (or one isn't circular enough by design). I've found in those cases a rubber band doesn't help, and gripping hard doesn't help, because you're distorting the shape of the filter's ring. This is more of an issue with cheap filters but a filter wrench can work wonders here.

Alternatively, if you have something you can put the filters face down on, like a jar gripper pad or mouse pad, sometimes carefully trying to unscrew the top filter without pushing down or squeezing the filter hard with your grip will work.

I'll try the ice cube trick. I checked and it's not cross threaded; screwed it now like I've always do. Thanks to everyone for your help.

If all else fails you can always resort to a hammer and chisel.

Finally got it; used the ice and then a sharp rap twice on the counter top.

Glad to hear it came off without any damage.


A few years ago when I was on a Navy ship, the presidential photographer had a stuck filter. The Navy photographers at the lab who was shooting with him also couldn't get the filter off. So they came to my shop to ask for my help. Get this..I didn't use any rubber bands or filter wrench ; I used my non-slip boot to get it off. So sometimes a military boot can also work.