Fixing damaged Polarizing filter
Jan 17, 2019 10:18:34 #
Jan 17, 2019 10:31:02 #
Toby wrote:
Not to be picky but if it is out-of-round, hitting it opposite the side it was originally hit on (if known) will increase the oval shape. You need to hit it at 90 degrees to the original.
Not to be picky lol...An oval is a curve resembling a squashed circle but, unlike the ellipse, without a precise mathematical definition. The word oval derived from the Latin word "ovus" for egg. Unlike ellipses, ovals sometimes have only a single axis of reflection symmetry (instead of two). You don't want to increase the oval shape (which shape it is in now (oval/out of round, egg shaped))... if it were like an ellipse you want to decrease the now major axis to the size of the minor axis. there by creating a circle. Hitting 90° to original strike may fix it but I really doubt it unless you go beyond the point of round where it may spring back to original diameter or roundness. You may also end up chipping the edge of the glass. Class is dismissed :)
Jan 17, 2019 11:31:02 #
RWR
Loc: La Mesa, CA
Toby wrote:
Not to be picky but if it is out-of-round, hitting it opposite the side it was originally hit on (if known) will increase the oval shape. You need to hit it at 90 degrees to the original.
I sure had a brain fart there - thanks for the correction!
Jan 17, 2019 11:37:08 #
The applied force vs deformation has two ranges: the initial is the linear, elastic range which has a force limit; beyond that limit is the non-linear plastic deformation range - removal of the force does not reverse the deformation to zero. So the filter ring deformation is permanent. So live with it or junk & replace - reversal of the deformation is not possible.
Jan 17, 2019 11:45:51 #
larryepage
Loc: North Texas area
It is going to be difficult to deform the ring enough to effect a repair with the element in place without breaking the glass. The glass may or may not be tempered, and may or may not be adhered to the polarizing gel. So be sure to wear some sort of eye protection while working around the element. Most likely, an effective repair is going to require disassembly. Otherwise deforming the element that needs fixing is going to result in undesirably bending parts that don't need to be bent. If it were me, and if the filter can be taken apart nondestructively, I'd be investigating whether I might find a lower cost polarizer into which I could remount the element. Or perhaps, although not likely, you might be able to purchase a filter "chassis" without the element, from the manufacturer and remount your good element in it.
Jan 17, 2019 13:20:32 #
rmalarz wrote:
I just got another off the wall idea. Get a hose clamp from your local hardware or car parts store. Make sure it's just the right size to fit the filter diameter. Place it around the filter and start to tighten it. You might be able to coax the filter back into a more round condition. At this point, it's worth a try. But, be prepared to purchase another filter.
--Bob
--Bob
Genuis lives amid the photog community!!!
Jan 17, 2019 14:42:31 #
Jan 17, 2019 15:33:49 #
amfoto1
Loc: San Jose, Calif. USA
A good metal "filter wrench" in the right size might be able to tweak it back into round and working condition.
Many of the affordable filter wrenches are plastic and wouldn't work.
The problem is that metal filter wrenches are expensive and are usually sold in sets with lots of sizes you wouldn't need.
I'd see if a local camera repairer has a set of them and would give it a try.
Many of the affordable filter wrenches are plastic and wouldn't work.
The problem is that metal filter wrenches are expensive and are usually sold in sets with lots of sizes you wouldn't need.
I'd see if a local camera repairer has a set of them and would give it a try.
Jan 17, 2019 15:58:16 #
Jan 17, 2019 17:27:31 #
Joexx wrote:
I have a Polarizing filter that does not rotate ea... (show quote)
You can probably get B&W to replace the metal frame and reuse the glass - call them and ask - they speak English and don't bite. Actually, they are very nice
Jan 17, 2019 17:52:47 #
rmalarz wrote:
I just got another off the wall idea. Get a hose clamp from your local hardware or car parts store. Make sure it's just the right size to fit the filter diameter. Place it around the filter and start to tighten it. You might be able to coax the filter back into a more round condition. At this point, it's worth a try. But, be prepared to purchase another filter.
--Bob
--Bob
Off the wall as it sounds, just place the hose clamp on each rotating part of the filter housing separately bringing the separate rotating and stationary pieces back into round, starting with the front part first, which it sounds to me, the part most likely to be out of round. Go in 1/8th screw-turn increments tighter once the clamp is fitted. My B+W, if I remember correctly, was brass, which should re-shape with a small amount of force. Delicate is the word here, along with readiness for replacement.
A tad further off that wall, place some thin tape inside the hose clamp to be sure not to mar the nicely finished filter you have.
Good Luck,
C
Jan 17, 2019 23:21:20 #
rmalarz wrote:
I just got another off the wall idea. Get a hose clamp from your local hardware or car parts store. Make sure it's just the right size to fit the filter diameter. Place it around the filter and start to tighten it. You might be able to coax the filter back into a more round condition. At this point, it's worth a try. But, be prepared to purchase another filter.
--Bob
--Bob
My thoughts exactly , except, just leave it on the filter. The tightening screw will give you more torque to turn it.
Jan 19, 2019 23:04:05 #
If you hit a ring containing two thin glass disks, something bad may happen.
That's why I suggested it will need to be disassembled (or at least the two rings separated).
That's why I suggested it will need to be disassembled (or at least the two rings separated).
Jan 20, 2019 07:21:21 #
John_F wrote:
The applied force vs deformation has two ranges: the initial is the linear, elastic range which has a force limit; beyond that limit is the non-linear plastic deformation range - removal of the force does not reverse the deformation to zero. So the filter ring deformation is permanent. So live with it or junk & replace - reversal of the deformation is not possible.
That depends on the material...
Jan 21, 2019 09:58:29 #
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