Seperating a filter that's stubborn stuck...

Tom Reichner wrote in post #19412046
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Good way to set off someone's motion-sensing car alarm, isn't it? . I am afraid to even gently brush against any parked car, let alone push something firmly into one of its tires. . Good way to embarrass yourself and run somebody's battery down to nothing and ruin their adventure.

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Yeah, here in crime crazy Los Angeles, doing that could result in an unwelcomed confrontation or worse.

RDKirk wrote in post #19413304
Leverage.

And convenience. I'm changing the filter, not the lens. It's not necessary to remove the lens from the body and then have to put the lens back on the body.

I’m a mechanical engineer so I’d be a bit concerned about the torque being applied to the body and lens components by the increased and perhaps undesirable leverage of gripping the body. It’s kind of like tightening a 1/4 inch nut with a 10-inch adjustable instead of a 4-inch adjustable. The potential for undesirable consequences become quite high IMO.

You could screw on a monopod. Use it as a cheater. Like breaking lug nuts.

John from PA wrote in post #19413315
I’m a mechanical engineer so I’d be a bit concerned about the torque being applied to the body and lens components by the increased and perhaps undesirable leverage of gripping the body. It’s kind of like tightening a 1/4 inch nut with a 10-inch adjustable instead of a 4-inch adjustable. The potential for undesirable consequences become quite high IMO.

Loosening, not tightening, though. And it only takes a quarter turn of a filter that will take several more turns before it comes away.

This is a matter of:

"Shucks, my filter is stuck." Looks around. "Truck!" Runs over, presses, twists, filter is loose. Remove filter and keep going.

I've been seeing this discussion of pushing to a flat rubber. How does this work on filters that rotate, like CPL and Variable ND?

FrostMonolith wrote in post #19413748
How does this work on filters that rotate, like CPL and Variable ND?

I can't see that it would...

in terms of leverage & earlier mentioned worry about breaking the lens mount if a body is still mounted, the only thing I would say is that it's surprising how many folks get the direction of "loosen" wrong...

FrostMonolith wrote in post #19413748
I've been seeing this discussion of pushing to a flat rubber. How does this work on filters that rotate, like CPL and Variable ND?

Yes, it does. If you push hard enough, you'll bind the polarizer and it'll transfer to the ring. I do it all the time with B+W polas that like to stick. Heliopans don't stick as much, but when they do, it works for them too.

docholliday_sc001 wrote in post #19413766
Yes, it does. If you push hard enough, you'll bind the polarizer and it'll transfer to the ring. I do it all the time with B+W polas that like to stick. Heliopans don't stick as much, but when they do, it works for them too.

I continue to be amazed at these methods of pushing enough to "bind the polarizer" and then turning by using the increased leverage of using the body. I would not do that with any of my vintage German lenses that are made dominantly of brass and I certainly would not do it with modern lenses that have the majority of the internal components (rings, cams, etc.) made from polycarbonate. Also tiny focusing motors and gearing that is not intended to be back driven. Review the content at https://www.canon.com.​cy …ens-developers-interview/ which is specific to the RF 70-200mm F2.8L IS USM lens. The content includes a cutaway showing the complexity of lenses today, many of which have polycarbonate internals for the sack of weight and ease of manufacturing.

John from PA wrote in post #19413783
I continue to be amazed at these methods of pushing enough to "bind the polarizer" and then turning by using the increased leverage of using the body. I would not do that with any of my vintage German lenses that are made dominantly of brass and I certainly would not do it with modern lenses that have the majority of the internal components (rings, cams, etc.) made from polycarbonate. Also tiny focusing motors and gearing that is not intended to be back driven. Review the content at https://www.canon.com.​cy …ens-developers-interview/ which is specific to the RF 70-200mm F2.8L IS USM lens. The content includes a cutaway showing the complexity of lenses today, many of which have polycarbonate internals for the sack of weight and ease of manufacturing.

I've done it with my Canons, 24-70v1, 70-200, 100-400, 16-35, 100L, 35L, Otus 55, and Distagon 21. I've also done it with my pile of Hasselblad HC/D lenses and my Phase One SK Blue Rings for XF. *Never* had an issue.

Oh, and back in the day, a pile of "vintage" Contax Zeiss lenses, both small format and 645 as well as Mamiya RZ glass. The only lenses I never did it to was my Hasselblad V lenses - which never bound because of the wonderful bayonet mount.

And who said anything about using the body? I always remove the lens from mount first and then do it. The tiny screws that hold the lens mount, even on the Hasselblad H5/H6 can distort or snap with excessive torque.

joeseph wrote in post #19413758
I can't see that it would...

in terms of leverage & earlier mentioned worry about breaking the lens mount if a body is still mounted, the only thing I would say is that it's surprising how many folks get the direction of "loosen" wrong...

Those people didn't get the filter on to begin with then. They didn't even get the lens on.

docholliday_sc001 wrote in post #19413789
I've done it with my Canons, 24-70v1, 70-200, 100-400, 16-35, 100L, 35L, Otus 55, and Distagon 21. I've also done it with my pile of Hasselblad HC/D lenses and my Phase One SK Blue Rings for XF. *Never* had an issue.

Oh, and back in the day, a pile of "vintage" Contax Zeiss lenses, both small format and 645 as well as Mamiya RZ glass. The only lenses I never did it to was my Hasselblad V lenses - which never bound because of the wonderful bayonet mount.

And who said anything about using the body? I always remove the lens from mount first and then do it. The tiny screws that hold the lens mount, even on the Hasselblad H5/H6 can distort or snap with excessive torque.

It would be amazing if the filter is on so tightly that removing it would shear the screws and overcome the lens mount.

I can't see how pushing against the front of the filter is going to help. All of the forces will be transferred from the side of each thread to the next one greatly increasing friction. It seems to be that you would want to minimize any force vector perpendicular to the filter threads. Griping the outer ring of the filter and applying all of the force parallel to the filter threads seems the best option by far. I can see a rubber band helping with grip, a filter wrench, or even a jar opener in a pinch, but shoving a lens against a tire and pressing hard while twisting seems a recipe for disaster.

docholliday_sc001 wrote in post #19413789
…And who said anything about using the body? I always remove the lens from mount first and then do it. The tiny screws that hold the lens mount, even on the Hasselblad H5/H6 can distort or snap with excessive torque.

RDKirk wrote in post #19411955
My contingency method of doing this in the field is to find a parked truck with big tires.

With the lens and the recalcitrant filter attached, push the front of the camera firmly against the sidewall of one of the truck tires (lean on it) and twist the camera counterclockwise.

And just how much do you push, a direction of force that for the most part a lens is not designed to accommodate.

John from PA wrote in post #19413850
And just how much do you push, a direction of force that for the most part a lens is not designed to accommodate.

gjl711 wrote in post #19413847
I can't see how pushing against the front of the filter is going to help. All of the forces will be transferred from the side of each thread to the next one greatly increasing friction. It seems to be that you would want to minimize any force vector perpendicular to the filter threads. Griping the outer ring of the filter and applying all of the force parallel to the filter threads seems the best option by far. I can see a rubber band helping with grip, a filter wrench, or even a jar opener in a pinch, but shoving a lens against a tire and pressing hard while twisting seems a recipe for disaster.

And yet, a bumblebee flies!

gjl711 wrote in post #19413847
I can't see how pushing against the front of the filter is going to help. All of the forces will be transferred from the side of each thread to the next one greatly increasing friction.

If it's stuck because it's fully on, then the threads are loaded on the "pushing the filter outward" direction. Pushing in not only gives traction to the rubber gripping surface, but it can unload those threads as well. This is part of how impact drivers work. Yes it increases the force on the bottomed-out contact area, but that seems to be less important than the thread contact area.

If it's stuck because the threads are corroded or something else, then this effect will not really apply.