Pentax SMC Takumar 1.4/50 Question

[heath]

I recently abtained the above mentioned lens in a bulk lot of photography equipment, including a SMC 55 1.8.

My problem is the 1.4 has a fungal growth in it. Not too bad, but I would still like to get her cleaned up. I will still shoot some shots with her as a test before any cleanup is attempted though.

Do any of you fellow members of this esteemed site know what needs to be done to clean up a fungal bloom in one of these lenses? Is it something that I could easily do myself, or should I send it to a more qualified and experienced person?

Any and all help on this matter will be greatly appreciated.

Heath

[vintageslrs]

Heath

there are other ways to achieve what you want. However, I know of one way...don't laugh OK?
The sun's UV rays will kill the fungus...don't know if it will clean the lens (lol) but it will kill the fungus.
I have been told to wrap the rear of the lens and the casing in aluminum foil. Leave the lens somewhere that it can get direct sunlight into the front of the lens. ( a window sill is OK). It may take up to 2 weeks but it will cure it
I think the most difficult part is finding a place that gets direct sunlight where it will not get disturbed by others in your household including pets.

good luck
Bob

[heath]

Thanks for the tip Bob. I will have to hunt around for a place, which may be hard to find here. We have two cats in this household.

Heath

[herron]

Heath:
If you can disassemble the lens, a 50-50 mixture of hydrogen peroxide and household ammonia will eliminate the fungus.
www.mamiya35collectors.com/fungus.htm

[John Parry]

Hi Heath,

Any 1.4 is worth trying to save. It sounds from your description as though the
infestation may not be too bad. It all depends whether the fungus has eaten
into the lens coating. If it has, you can only take drastic steps to remove the
coating altogether (acid), and then put up with any flare you get.

There is a special tool for removing the front and rear elements, which is pretty
pricey if you are only going to use it once. An alternative is to make up a tool
to fit the retaining piece slots from a 'bulldog' type paper clip. These are rigid
enough to be able to turn the retainer ring, but thin enough to be easily worked
with wire cutters.

Once you have the offending element out, my advice is to use ordinary washing-up
detergent applied neat on a paper towel before using exotic chemical combinations.
You may need the chemicals if the detergent doesn't work, but it's at least worth a
try first.

MOST IMPORTANT: If you are cleaning and rinsing the lens over a sink (the best method), drape a towel right across the sink leaving no exposed area. I managed to clean a couple of lenses beautifully, only to let them slip. The resulting chips at the edge of the lenses rendered them totally useless!

Regards - John

[herron]

Heath:
I'm sure John is referring to a spanner wrench, which can indeed be pricey if it is only going to be for a one-time use. I used to think so, too...until the second, third and fourth time I could have used one! Not to mention the scratches I put on lens rings by trying to adapt things to work. If I had been handier, I suppose I could have made a spanner wrench, but my past experience tells me that I would have the satisfaction of knowing I could make one, at several times the cost of just buying it! But then, that's me.

Needless to say, I bought a set, and have used them a lot. They have paid for themselves many times over, by not having to send a camera out for repairs.

Micro-Tools has quite a selection of spanner wrenches, some at reasonable prices:
www.micro-tools.com/Merchant2/spanner.htm

Lens fungus is not all that hard to remove, if you can get at the elements. The ammonia-hydrogen peroxide solution really works, and you can find both, inexpensively, in the grocery store or pharmacy. It doesn't take much. I usually put a little into those small plastic travel bottles, so I don't have gallon jugs of ammonia, or large bottles of HP, in my work area -- and I usually apply it with Q-Tips!

Just mild soap and water washing can provide some relief, but it often doesn't end the problem, because if any fungus residue remains at all, it will likely grow back. Using a Q-tip and the solution on the lens barrel inside is recommended too, since fungus will also grow there. It is a good idea to use a mild soap and water rinse as a recommended final step.

John brings up some other very valid points. If the fungus has destroyed parts of any coating, your only choice to save the lens may be to try to remove all the coating with a mild acid bath...but there can be consequences to that, too, not all of them something you're going to look forward to.

And John is particularly right about making sure there is a soft surface everywhere, in case the lens slips out of your grip. There is probably nothing more frustrating than eliminating all the fungus from a lens, knowing it is a pristine piece of glass again, only to drop it and have that perfectly clean chip staring you in the face!

Good luck!
;D

[heath]

Again, thanks for all the valuable advice you have given me.

I had a good look at the lens and there are no small slots for a spanner wrench.
I am at a loss at how to open the lens. Any idea's on this?

Thanks in advance.

Heath

[herron]

heath said:

I had a good look at the lens and there are no small slots for a spanner wrench.
I am at a loss at how to open the lens. Any idea's on this?

Heath:
I have to believe there are slots for a spanner wrench on the "inside" lens...if not, the whole inside assembly must come apart with screws somewhere.

On the lens ring, a lot of cameras have no spanner slots. That's where you need a gum rubber tool, like the ones they sell on Micro-Tools, toward the bottom of this page:
www.micro-tools.com/Merchant2/lens.htm

It lets you get a grip on the lens ring without damaging the glass or the ring itself. I suppose you could "make" one...but I've never been that handy!


I hope this helps.

[PeterW]

Heath,

I've been inside sevearl lenses to clean them where there doesn't seem to be any slots or holes on the name ring at the front of the lens. These rings are usually screwed in on the same threads used for a filter and, as Ron said, you need a rubber gripping tool to undo them. Being a cheapskate I usualy make my own, either from an old rubber door stop or something similar. I've even cut down an old ice hockey puck. The rings aren't usually screwed in all that tight, and on one lens I undid it with my thumbs using a pair of household rubber gloves with gripping pads on the thumbs. Behind the name ring there's usually either a ring with spanner holes or a circlip to hold the front element group in.

Peter

Peter