[PGillin]

I need some help. I recently bought a Soligor Macro/Zoom lens (M42, FWIW), and it has a severely dented filter ring. This is a problem, because the front element threads in and out through the filter ring, and I need to clean the front element. I sprayed some lens cleaner on, and it got in behind the front element and formed a hell of a film. It's not supposed to, but it did.
Basically, if the filter ring has about a 1/2-1mm dent, can I do anything about it?
Also, if it is fixable, how do I get the front element out? I can tell the retaining ring just threads out, but what tool do I use to thread it out?

All advice is appreciated. Thanks.

[ramseybuckeye]

I need some help. I recently bought a Soligor Macro/Zoom lens (M42, FWIW), and it has a severely dented filter ring. This is a problem, because the front element threads in and out through the filter ring, and I need to clean the front element. I sprayed some lens cleaner on, and it got in behind the front element and formed a hell of a film. It's not supposed to, but it did.
Basically, if the filter ring has about a 1/2-1mm dent, can I do anything about it?
Also, if it is fixable, how do I get the front element out? I can tell the retaining ring just threads out, but what tool do I use to thread it out?

All advice is appreciated. Thanks.

You might try a toolmaker to get the dent out, hopefully it could be done without contact to the glass. The barrel may be slightly out of round from the contact that dent, which would explain why the cleaner could get beind the element so easily. Hopefully someone with a lens repair background will help you out. I tried to bend a dented filter ring once with no luck. I was afraid to put to much pressure on it and stress the barrel further down. I ended up just selling it as a damaged lens.

I hope you got it cheap, but good luck.

[pacerr]

Or a jeweler.

There's a coupl'a ways you can try yourself though.

Make a rod from, say, a hardwood dowel about 1/4" diameter or a sawed-off plastic toothbrush handle works well. Rest the lens on a firm but non-marring surface with the dent down. Very gently tap on and around the dent using the rod and a light tap hammer. Takes patience but I've done it many times.

For a larger dent, build a die set in the form of a crescent (from wood scribed around the circumference of the lens perhaps or I've poured epoxy into a pocket made with tape on the front of an old filter). A hole saw of the approximate diameter in an electric drill makes a quick and easy wooden die set. What you want is matching positive and negative curved surfaces that can be squeezed with pliers or Vise-grips. Follow up with the tap rod described above.

With an older junker lens, the easiest way is to simply file or nibble out the dent! That leaves you with a gap-toothed smile in the filter ring but everything's still functional. A UV filter, or the empty ring from a glass-less filter, can be used to reinforce and/or restore the rim if desired. This may be the only easy solution for a lens with a damaged plastic filter ring. Or you may find a "donor part" using barrels from salvaged junk lenses that make a slip-fit over the original filter ring - trim and glue it in place,and maybe add a little length for a built-in hood while you're at it.

I often use draftsman's dividers as a spanner wrench to start the retainer ring. An old caliper (a measuring device) with the blades filed to suit also makes a good adjustable spanner wrench for the slotted rings.

H2