Stuck polarizer. Help!

[Kino]

Chances are you're going to pry that ring off and find out WHY it was glued there in the first place...

 

[eli griggs]

Using a proper filter wrench applies force circumferentialy and doesn't deform the shape of the filter. The problem with 'rubber sheet/bung' methods is that it is a polarizing filter so the front of the filter rotates freely.

The suggestion of freezing the lens & filter may have some merit. Try to remove the filter as soon as it is taken out of the freezer - or do it in the freezer if it is big enough. This assumes the aluminum of the filter has a greater coefficient of expansion, er contraction, than the plastic.

If you freeze it, moisture will form inside the lens when it is defrosted.

Do not do it!

 

[eli griggs]

Just another question in this thread that is beginning to resemble the Painless Potter advice for the gunfight scene.

If it is crazy glue then isn't there something that can soften/melt it or is the cure in this case worse than the disease because the risk of damage to the lens?

Just a thought

pentaxuser

Crazy glue, like other "super" glues is removable with acetone and if you're camera lens barrel is plastic, it will damage it.

I doubt the filter was super glued, as no one I can think of would do it and, experience showed me super glues out gas and will foul an optic, if in an enclosed space.

ie, the Eddy Murphy film Beverly Hills Cop, where he put super glue into a terrarium so the gas would show him a fingerprint.

The heat method I suggested will not melt the lens, as the heat is low, and the time on the pan is so brief.

Any plastics on the lens and camera should have a much higher melt temperature.

Gool luck.

PS: do no put any part of it in boiling water!

 

[eli griggs]

All good suggestions but one can also take it to a camera repair place.

Besides could condensation, freezing to shrink the filter, will make the tighter and you want it loose.

Heat expands and a heated ring on the flat pan, will heat jyst the ring first, instead of shrinking the entire assembly at the same time in the freezer.

Think about it.

 

[Nicholas Lindan]

freezing to shrink the filter, will make the tighter

????? The lens has external threads and the filter internal. You want to make the filter smaller so it pulls away from the lens threads. If you make the filter hotter it expands and gets tighter in the threads. All assuming the coefficient of expansion for aluminum is greater than that of plastic.

If one are paranoid about condensation slip caps on both ends. The air inside the lens isn't going to have any effect - there just isn't enough air that has enough moisture in it.

In any case this is a theortical argument for the sake of having an argument.

I agree with the 'leave it on the lens' solution. A drop or two of crazy glue to keep the ring from turning would be a help with using it all for a filter mount -- one that won't jam up.

 

[Alan Edward Klein]

Ah, that's what that stop is for.

These stops use to be on all Nikon polarizing filters. Not sure if they still do it.

 

[eli griggs]

????? The lens has external threads and the filter internal. You want to make the filter smaller so it pulls away from the lens threads. If you make the filter hotter it expands and gets tighter in the threads. All assuming the coefficient of expansion for aluminum is greater than that of plastic.

If one are paranoid about condensation slip caps on both ends. The air inside the lens isn't going to have any effect - there just isn't enough air that has enough moisture in it.

In any case this is a theortical argument for the sake of having an argument.

I agree with the 'leave it on the lens' solution. A drop or two of crazy glue to keep the ring from turning would be a help with using it all for a filter mount -- one that won't jam up.

No, I said no to freeze the lens, filter as both will shrink, so use mild heat to EXPAND the filter ring only.

 

[pentaxuser]

Crazy glue, like other "super" glues is removable with acetone and if you're camera lens barrel is plastic, it will damage it.

OK thanks

pentaxuser

 

[Sirius Glass]

No, I said no to freeze the lens, filter as both will shrink, so use mild heat to EXPAND the filter ring only.

They will only shrink or expand at the same rate if and only if all the parts are made of the same materials in the same way.

 

[Nicholas Lindan]

Mea Culpa.

My assumptions have, again, made an ass of me. Lesson - always look it up first.

Plastic has ~3 times the coefficient of expansion/contraction than aluminum.

So, to get the filter off you would heat the plastic and not the filter; well, you can heat both and it won't make much difference.

Heating the lens likely gets grease all over the diaphragm and other bits.

Heating just the aluminum will bind the filter as the filter threads will expand into the plastic.

 

[Xylo]

If I had access to a small block of dry ice, I would just chill the ring with that, but that's not the case

 

[mshchem]

If I had access to a small block of dry ice, I would just chill the ring with that, but that's not the case

Liquid nitrogen would work too!

 

[eli griggs]

They will only shrink or expand at the same rate if and only if all the parts are made of the same materials in the same way.

There is no benefit to freezing and shrinking the threads to be tighter, IMO, as heating for a few seconds, on low, is a much quicker and appropriate method.

Godspeed

 

[eli griggs]

Mea Culpa.

My assumptions have, again, made an ass of me. Lesson - always look it up first.

Plastic has ~3 times the coefficient of expansion/contraction than aluminum.

So, to get the filter off you would heat the plastic and not the filter; well, you can heat both and it won't make much difference.

Heating the lens likely gets grease all over the diaphragm and other bits.

Heating just the aluminum will bind the filter as the filter threads will expand into the plastic.

The heating will be too low to melt that plastic and is only there to expand the ring well enough to break tension between the two.

Talk about any "melting" is a canard, there is no enough temperature and time to make it so.

 

[mshchem]

The heating will be too low to melt that plastic and is only there to expand the ring well enough to break tension between the two.

Talk about any "melting" is a canard, there is no enough temperature and time to make it so.

 

[mshchem]

Just a tickle

 

[eli griggs]

View attachment 344904

OK, that there is melting!

 

[Dan Daniel]

Does anyone know what material is used in the plastic for this lens? Many plastics are not affected by acetone, the standard solvent for superglue.

OP, you can take a very small brush and put a drop of acetone on a part of the plastic. Let it sit and evaporate and see if a mark is left. Nylon, polyethylene, and many others will not melt under acetone. And are there any signs of superglue such as whitish frosting gas-off trails?

If it looks fairly safe, dripping a very small bead into the seam a few times could help.

And although I know this will draw more derision, I assume from people with no finesse and fine touch, a Dremel can be used. Notch with a burr. Finely carve away when you get to the area of threads on the lens. A diamond burr and a good touch would let you remove almost all of the filter mount and barely graze the lens threading. Protective tape over the rest of the lens. And hitting the lens threading in a small section is not as horrific as some might think. Plenty of threads left for proper attachment. And a little dressing would make any marks almost invisible.

 

[Xylo]

There is no benefit to freezing and shrinking the threads to be tighter, IMO, as heating for a few seconds, on low, is a much quicker and appropriate method.

Godspeed

Actually, aluminum is heat conductive, plastic is not. Also, aluminum has a contraction ratio much greater than plastic. The hope with such a technique is that the aluminum would shrink enough to actually break the glue bond allowing the ring to be removed.

Such a technique wouldn't work with a metal lens housing as it also would be affected by the cold.

Liquid nitrogen would work too!

I strangely don't see myself walking into a dermatologist's office asking for a bit of their liquid nitrogen in a cup

 

[Nicholas Lindan]

Also, aluminum has a contraction ratio much greater than plastic.

That's what I thought.

I looked it up, to make sure I wasn't talking out my bum: Al 23E-6, Plastics ~75E-6, both per degree C. https://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

I was talking out my bum.

Plastics, it seems, expand & contract about 3x more than aluminium.

 

[eli griggs]

Actually, aluminum is heat conductive, plastic is not. Also, aluminum has a contraction ratio much greater than plastic. The hope with such a technique is that the aluminum would shrink enough to actually break the glue bond allowing the ring to be removed.

Such a technique wouldn't work with a metal lens housing as it also would be affected by the cold.


I strangely don't see myself walking into a dermatologist's office asking for a bit of their liquid nitrogen in a cup

There are aerosols that will super cool items held close, such as canned "airs" used to blow off dust.

Medical cooling aerosols are also very cold held close and I've used these as a medic in the long ago, in the desert, etc, to cool/numb flesh, though you'll have to look about some to find them.

 

[Xylo]

The only thing with those is the short duration of the cold cycle. I don't know if they would last long enough for the cold to penetrate the materials in a substantial way.