Bent filter thread, and its repairability?

[George Mann]

I have a zoom lens to present to all of you that was posted for free on this website. It has a hard lifted bend in its filter ring. Can a filter ring wrench successfully fix this?

 

[rcphoto]

If that is a damaged filter ring I would clip it with some side cutters and then "roll" it out with some needle nose pliers. If you try and twist it out you may damage the threads on the lens. This was my method for years when I was working in a camera store.

 

[Paul Howell]

I have a filter ring repair tool I bought from Amazon

 

[Jim Jones]

There are tools designed to restore moderate filter thread damage. However, I've improvised substitutes for such tools for occasional restoration of less severe damage. In a piece of wood cut a concave support that fits the lens outside of the filter thread in an undamaged part. Curve one end of a thin piece of hardwood to fit the filter threads. Sharpen this end so the wood reaches the bottom of the threads. With the damaged area of the lens supported in the concave section of the large tool, seat the curved end of the second tool in the bottom of the damaged thread and hammer the other end to gradually straighten the threads. It helps to have a third hand while doing this. Probably alternately working from each end of the damaged area is better than starting in the center, especially with that much damage. A cruder quick fix is to remove the glass from an old filter, and file or grind the male threads of this filter ring down to their roots. Cut away a section of these mutilated threads in a section as long as the damaged area of the lens. Glue this filter ring onto the lens. A semi-permanent glue is advised, so you can later do the repair right, if desired.

 

[Sirius Glass]

Jim recommends something that I tried and it did not work for me. Be ready to have a repairman replace the ring.

 

[Dan Daniel]

I'll second rcphoto's recommendation as the simplest, quickest way out. Cut the bent part away. I was given a nice lens with about 1/4 of the threads smashed in. Took a Dremel and ground it all away. A filter isn't under a lot of pressure, so 2/3 or so of threads left is more than enough to keep the filter in place.

Of course this ruins any collector value...

 

[Sirius Glass]

I'll second rcphoto's recommendation as the simplest, quickest way out. Cut the bent part away. I was given a nice lens with about 1/4 of the threads smashed in. Took a Dremel and ground it all away. A filter isn't under a lot of pressure, so 2/3 or so of threads left is more than enough to keep the filter in place.

Of course this ruins any collector value...

Or usefulness for screw in filters.

 

[rcphoto]

I had interpreted this as a damaged filter ring (the OP was asking if a filter wrench would help). If it's a damaged barrel then my suggestion is irrelevant.

 

[Dan Daniel]

Or usefulness for screw in filters.

No, actually, if you cut away a section of the filter threading to eliminate the area bent, the rest of the filter threads that are still in the right shape will hold a filter. Threads don't care if there are matching threads for all 360 degrees of the circumference. As long as there is no interference, the threads just mate. You simply need enough threading to keep the overall filter in a proper orientation. I bet you could create three small tabs of 10 degrees each at 120 degree points on the outer ring and have a filter work just fine. Until one of the tbs gets bent or such.

Well, you might need to clean entrance and exit points on threads after grinding them down. A simple thing to do.

Of course this is all McGyver hacking. When you worship pretty boy Hassy chrome, such talk of mine is blasphemy.

 

[xkaes]

Those filter "wrenches" don't work. They put the same amount of pressure on the opposite side -- and press it outward to the same degree as the side you are trying to fix. You just end up with TWO dents.

 

[BobD]

I have fixed many dents like that with a good old
"church key" type can opener. I use a lot of padding and bend a little at a time. When I get close to a normal shape I screw a filter on and off until it can go on easily.

 

[Mamiya_Repair]

Those filter "wrenches" don't work. They put the same amount of pressure on the opposite side -- and press it outward to the same degree as the side you are trying to fix. You just end up with TWO dents.

I agree! Save your money and don't buy these so called filter ring tools. The way to fix filter ring dents (and yours is not too bad, it can be straightened out and filters installed) is with a form to fit the curve of the ring and a wooden forming tool with also the same curvature of the lens ring. This is trivial for a repair shop to fix and if you want to do it on your own, you can make a form out of wood. If you want details on what the tool looks like to make your own, go to my webpage and I have a link to my Instagram posts-I did an illustrated post on this issue about two months ago.

 

[OAPOli]

I fixed a bad dent on a P67 lens using a concave wooden form against the barrel and a matching convex one to press on the dent. Used a vise to slowly bring pressure. I don't recommend using a hammer! I tried and it didn't work, plus the shocks could upset the optics. In my case the reshaped metal got a tiny fatigue crack at the fold but filter usage was restored.

 

[xkaes]

And you don't have to get the repair PERFECT. Just good enough to screw-in/force-in a UV filter. Then additional filters will fit fine.

 

[mshchem]

If you repair this will you use a filter? I would use it as is.

It's the kind of thing that drives me crazy. I once threw out a beautiful old 620 folder, 4 hours later I was digging through my garbage to rescue it. I still have it, someday I will have the shutter cleaned, why I don't know.

 

[beemermark]

The filter wrench works just fine. Just need to go slow, a little at a time, and start at the ends of the bend and work it out slowly. There's always a chance with a dent like yours that the lip will break. In that case do as others have said and just cut that section out. Then take a cheap filter that isn't any good (scratches in he glass usually) and remove the glass. A little super glue, thread the new filter minus glass onto the lens. You know have a new lens barrel with 100% filter thread. If you care about looks when the new filter ring is installed you can put a little epoxy in the gap left by the missing lens thread and paint it black.

 

[albada]

There are tools designed to restore moderate filter thread damage. However, I've improvised substitutes for such tools for occasional restoration of less severe damage. In a piece of wood cut a concave support that fits the lens outside of the filter thread in an undamaged part. Curve one end of a thin piece of hardwood to fit the filter threads. Sharpen this end so the wood reaches the bottom of the threads. With the damaged area of the lens supported in the concave section of the large tool, seat the curved end of the second tool in the bottom of the damaged thread and hammer the other end to gradually straighten the threads. It helps to have a third hand while doing this. Probably alternately working from each end of the damaged area is better than starting in the center, especially with that much damage. A cruder quick fix is to remove the glass from an old filter, and file or grind the male threads of this filter ring down to their roots. Cut away a section of these mutilated threads in a section as long as the damaged area of the lens. Glue this filter ring onto the lens. A semi-permanent glue is advised, so you can later do the repair right, if desired.

I have used this wooden-curved-support method with good results. On the inside of the thread, I tap a wooden dowel with a rounded end with a hammer, starting at the end of the dent and working toward the middle. For this severe dent, you should make several end-to-middle passes, with each pass straightening the dent a little.

 

[Sirius Glass]

I have used this wooden-curved-support method with good results. On the inside of the thread, I tap a wooden dowel with a rounded end with a hammer, starting at the end of the dent and working toward the middle. For this severe dent, you should make several end-to-middle passes, with each pass straightening the dent a little.

Go v-e-r-y s-l--o---w----l-----y

 

[250swb]

Those filter "wrenches" don't work. They put the same amount of pressure on the opposite side -- and press it outward to the same degree as the side you are trying to fix. You just end up with TWO dents.

No they don't cause two dents. They apply pressure spread evenly around the arc on the opposite side (fewer foot pounds of force across the whole area), but put point pressure (more foot pounds of force) on the dent, while ever there is a high point in the dented area that is what will have most pressure applied to it. Of course you need to stop when the dent is out, but I guess somebody with the mechanical sympathy of a gorilla may carry on winding and then cause two outward dents, who knows? As far as the OP's dent is concerned it's probably easy to make it round again, but the threads will still be distorted.

 

[George Mann]

Thanks for your help. I decided not to take this project on since I have no logical need for the lens. I could of had it for the price of shipping, but I have too many unuseable "bargain" lenses as it is..

 

[DREW WILEY]

Ha! I was in a remote un-trailed mountain basin an entire weeks walk from the truck over several high passes. My hiking companion was experimenting with a prototype tent that didn't have its own poles, and used his trekking poles instead. And that of course left him without any poles to use once we were camped. And that evening he was out shooting his expensive Contax 6X6, attempting to cross a creek, and slipped. Two legs of his new Gitzo CF tripod were broken, he dunked his camera in icy water, the rim of it got dinged, and his own heel was injured. Thank goodness he brought some duct tape along. I took some whitebark pine branches and whittled him a couple of prosthetic legs to tape to his tripod and get it working again, and from a little stick of it made a notched pry device to pull back out the rim of his 2000 dollar Zeiss lens. It actually worked, and it accepted filters again. And he wrapped enough duct tape around his heel and ankle to manage the long hike out. There were other memorable predicaments on that trip, but these are enough for this thread.

 

[Sirius Glass]

Ha! I was in a remote un-trailed mountain basin an entire weeks walk from the truck over several high passes. My hiking companion was experimenting with a prototype tent that didn't have its own poles, and used his trekking poles instead. And that of course left him without any poles to use once we were camped. And that evening he was out shooting his expensive Contax 6X6, attempting to cross a creek, and slipped. Two legs of his new Gitzo CF tripod were broken, he dunked his camera in icy water, the rim of it got dinged, and his own heel was injured. Thank goodness he brought some duct tape along. I took some whitebark pine branches and whittled him a couple of prosthetic legs to tape to his tripod and get it working again, and from a little stick of it made a notched pry device to pull back out the rim of his 2000 dollar Zeiss lens. It actually worked, and it accepted filters again. And he wrapped enough duct tape around his heel and ankle to manage the long hike out. There were other memorable predicaments on that trip, but these are enough for this thread.

Does this kind of thing happen to your hiking buddies often? Jes' askin'

 

[DREW WILEY]

That kind of thing is just the tip of the iceberg. It's been an interesting life. Surprised I survived. But all those wilderness incidents put together didn't scare me half as much as my daily commute here on the freeway before I retired. I certainly saw a lot more death and utter foolishness on the freeway. Even heading toward the mountains for my many treks over the decades, the most dangerous part of the whole trip was simply the first hour getting away from the city and all the wacko idiots on the road. But crossing the Central Valley had to be done during the right hours in Winter and Spring before the awful tule fog condensed. Drivers could hardly see the front of their own car hood, yet would still drive 90mph. I've known of pileups in the fog involving over 250 automobiles. Rattlesnakes, bears, mountain lions, and even avalanches, are downright polite compared to the typical highway idiot mentality.

 

[Sirius Glass]

That kind of thing is just the tip of the iceberg. It's been an interesting life. Surprised I survived. But all those wilderness incidents put together didn't scare me half as much as my daily commute here on the freeway before I retired. I certainly saw a lot more death and utter foolishness on the freeway. Even heading toward the mountains for my many treks over the decades, the most dangerous part of the whole trip was simply the first hour getting away from the city and all the wacko idiots on the road. But crossing the Central Valley had to be done during the right hours in Winter and Spring before the awful tule fog condensed. Drivers could hardly see the front of their own car hood, yet would still drive 90mph. I've known of pileups in the fog involving over 250 automobiles. Rattlesnakes, bears, mountain lions, and even avalanches, are downright polite compared to the typical highway idiot mentality.

They are driving so fast to beat the next driver so that they are ahead by one car at the next stop light.

 

[DREW WILEY]

Not here. They run right through red, often deliberately, especially teenagers showing off to their teenage passengers. Seen em run lights right in front of oncoming semi trucks, deliberately, repeatedly. But on the freeway, the thing to do is lane-splitting right between cars - not just in motorcycles, but in actual cars at high speed. That happened to me about twice a week. Fortunately, I was already retired before Covid, when bored teens 20-somethings started really driving insane - often racing each other over 100mph on the freeways. Not surprising the death rate went up too, despite less overall traffic. Now nearly all the traffic and is back, but the same horrible habits haven't diminished. I've had a lot of cumulative close calls in the mountains, but nothing like the constant threat of mortal danger on the otherwise simple commute just 8 miles to the workplace.