Help with jammed filter.

[Les Olson]

I recently pointed out that the population of Ai-S lenses in the world would continue to fall, because one by one they would suffer unfortunate accidents.  Karma being what it is, I promptly dropped my 50/1.4 Ai-S two metres onto pavement.  It was wearing a yellow filter (B&W, brass ring) which, fortunately, took the impact.  In a testament to old-fashioned build quality the lens appears to be unharmed and the filter, as well as cracked glass, has only a small dent where it hit the asphalt, but it is now jammed on the filter ring. 

Does anyone have suggestions for getting the filter off?  If I have to drill through the metal of the filter ring, can I preserve the filter threads on the lens?  The lens is usable as it is, because the cracks in the filter glass are visible through the viewfinder only at f/16, so it is not a nothing to lose situation. 

[michel]

This may help you

http://www.ebay.fr/itm/49-52-55-58-67-72-77mm-Combo-Kit-Cle-Pour-Filtres-Objectif-Appareil-Photo-/401042192258?hash=item5d5ffa3782:g:FA8AAOSw~otWcCp~

[Bjørn Rørslett]

Filter wrenches, if they are fitting adequately to the filter diameter, should solve the stuck item.

Pushing the lens hard onto a huge rubber stopper then twisting off the stuck filter in some cases works equally well.

[Andrea B.]

ouch! Happy the lens itself was not hurt.

There are also those rubber jar opener discs as used in the kitchen. Won't scratch and permit a good grip on the filter. Here is a (randomly chosen) link from Amazon to show you what I mean. One of them is like the rubber stopper Bjørn referred to. The others are flat.
https://www.amazon.com/Prepworks-Progressive-Jar-Grips-Set/dp/B00F67TLFC/ref=pd_lpo_vtph_79_bs_lp_img_2/134-4626238-8400560?_encoding=UTF8&psc=1&refRID=DBBGDJY3PHBHYFRKDX64

When my entire rig (tripod, camera, lens) went over the side of an embankment and fell on a granite slab (everything survived, amazingly!!), I had that kind of stuck filter with a dent in the lens rim where the filter threads are. Given that the lens took such a fall, I decided to send the lens in and let Nikon techs pry the filter off and check the lens out for any loosened elements, etc. They have the tools to make such repairs. So, there's always that if you cannot remove the filter yourself. The techs were able to make the dented rim better also so that filters could still be used.

[richardHaw]

if the threads of the front ring is warped from the fall then the only way to get that out is by destroying the filter 

I did this with a 50-300 and the front filter was soooo big  it took me some time to get the thing off...

[Øivind Tøien]

I once removed a stuck filter by touching it for a few seconds to a cold pack that came out of a -80°C freezer, and then quickly removed the filter with a leather gloved hand. It went very easily.

[Les Olson]

I once removed a stuck filter by touching it for a few seconds to a cold pack that came out of a -80°C freezer, and then quickly removed the filter with a leather gloved hand. It went very easily.

Good idea.  Thermodynamic orthodoxy says you have to cool the filter ring and the threads.  If you only cool the filter it will be stuck worse, but if you cool both it will be looser.

[Bjørn Rørslett]

I'm getting curious as to how your filter issue was solved?

[Akira]

I would also go for the filter wrenches or the non-slip rubber.

I once removed a stuck filter by touching it for a few seconds to a cold pack that came out of a -80°C freezer, and then quickly removed the filter with a leather gloved hand. It went very easily.

Øivind, that sound great, but I wonder how the ordinary people like us can have a -80 degree centigrade freezer near at hand!?   

[Øivind Tøien]

I would also go for the filter wrenches or the non-slip rubber.

Øivind, that sound great, but I wonder how the ordinary people like us can have a -80 degree centigrade freezer near at hand!?   

I would try a cold pack from a -20°C freezer (1/2 the temperature gradient) and go 2x as long.   

Good idea.  Thermodynamic orthodoxy says you have to cool the filter ring and the threads.  If you only cool the filter it will be stuck worse, but if you cool both it will be looser.

As the cold pack was in contact with the filter front and created a very steep temperature gradient, I think most of the effect would be on the filter although hard to verify. While the filter shrinks axially, likely the major effect is shrinking the diameter of the filter (there is much more metal in that direction to shrink) to loosen it up. The filter ring in that case was not damaged (it has currently been transformed to a solar filter), but tiny glass shards were locking up the threads.

[Les Olson]

Thanks everyone for the suggestions. 

The freezer did not help.  The rubber bung did not help.  The kitchen gadgets did not help - we have several because I am left handed and my wife is right-handed, so I keep putting lids and caps on too hard for her to get off (in humans forearm pronation - turning the palm downwards - is much stronger than supination, so caps and taps and so on go on and off the directions they do because on is supination and off is pronation for right-handers, so it is unlikely things will be put on so you can't get them off, but for left-handers the arrangement is a disaster waiting to happen).  A pipe wrench did not help, before or after the freezer, within the limits of my nerve given that I don't want to break the lens.  The filter wrench is in the mail, but I don't have a lot of hope it will work when a pipe wrench has failed. 

If the filter wrench does not work it will be a choice between sending it to Nikon or drilling through the ring, accepting that will probably wreck the lens threads. 

[Bjørn Rørslett]

We'll have to wait and see with abated breath then

The filter wrench has more "bite" is it is flexing and thus there is much less risk of damaging the front casing of the lens whilst a larger pressure can be brought to bear on the stuck filter.

[richardHaw]

 

[David H. Hartman]

I once had to remove a filter from a AI Nikkor involved in a similar mishap. I carefully removed all the glass from the filter then I cut the filter ring probably with a fine toothed hacksaw blade. [I may have use a very small file to cut the filter ring.] Finally I used pliers to break the ring while twisting it inward and lifting it away from the front element. The filter ring was probably aluminum, probably a Nikon or Hoya filter. The lens was my father's lens. I found no problems with the lens either optically or mechanically. There was no cosmetic damage either.

You really roll the dice in an incident like this. 

Dave Hartman

[Les Olson]

The filter wrench did not help.

What helped was a triangular file, applied parallel to the glass surface.  It was not necessary to disturb the threads, just file down just beyond the glass surface.  The lens filter threads are fine - they accept a filter readily.